The High Pressure belt in the Grenville Province: architecture, timing, and exhumation

SL1 is adjacent to the Grenville Front.

“In the northwestern part of the Grenville Province in Ontario (Fig. 2), the architecture, metamorphism and interrelationships of terranes and domains have been investigated in detail and the threefold lithotectonic subdivision shown in Fig. 1 has been refined into at least six structural levels (SLs; e.g., Culshaw et al. 1997; Ketchum and Davidson 2000), with the lowest (SL1) being adjacent to the”

• cites Culshaw et al. 1997 sourcePartly supported

  Section 2.2 (page unavailable) says the Grenville Front Tectonic Zone abuts the foreland along the Grenville Front, supporting the location of the frontmost zone. The paper does not identify that zone as “SL1” or use the citing document’s structural-level numbering, so it does not establish the specific SL1 attribution. (LLM, conf=0.78)

  Experimental — accuracy not yet measured
• cites Ketchum and Davidson 2000 sourceNot checked — no full text of the source

Contractional displacements on front-parallel structures have resulted in a rise in metamorphic grade towards the interior of the orogen.

“Grenvillian planar fabrics in the Parautochthonous belt are generally subparallel to the Grenville Front, and contractional displacements on frontparallel structures have resulted in a rise in metamorphic grade towards the interior of the orogen (Haggart et al. 1993; Rivers et al. 1993; Jamieson et al. 1995).”

• cites Haggart et al. 1993 sourcePartly supported

  The Introduction (page not available) describes an increase in metamorphic grade inward from the Grenville Front, and the Tectonic Interpretation links convergence and shear-zone movement to exhumation. But its conclusions say the high-grade assemblages in the western Grenville Front Tectonic Zone predate Grenvillian deformation and were exhumed with little or no metamorphic overprinting. The paper therefore supports the spatial grade pattern and a role for deformation in exposing it, not the stronger implication that contractional displacement produced the higher metamorphic grade. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites Rivers et al. 1993 sourceNot checked — no full text of the source
• cites Jamieson et al. 1995 sourceNot checked — no full text of the source

In the northwestern part of the Grenville Province in Ontario, the threefold lithotectonic subdivision shown in Fig. 1 has been refined into at least six structural levels (SLs).

“In the northwestern part of the Grenville Province in Ontario (Fig. 2), the architecture, metamorphism and interrelationships of terranes and domains have been investigated in detail and the threefold lithotectonic subdivision shown in Fig. 1 has been refined into at least six structural levels (SLs; e.g., Culshaw et al. 1997; Ketchum and Davidson 2000), with the lowest (SL1) being adjacent to the”

• cites Culshaw et al. 1997 sourcePartly supported

  The Introduction (page unavailable) describes the three major divisions of the Grenville Province in Ontario, then identifies the Grenville Front Tectonic Zone and five first-order subdivisions of the Central Gneiss Belt along the Georgian Bay transect. This supports a more detailed subdivision of the northwestern area, but the paper does not identify those six units as numbered structural levels (SLs). (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites Ketchum and Davidson 2000 sourceNot checked — no full text of the source

Grenvillian planar fabrics in the Parautochthonous belt are generally subparallel to the Grenville Front.

“Grenvillian planar fabrics in the Parautochthonous belt are generally subparallel to the Grenville Front, and contractional displacements on frontparallel structures have resulted in a rise in metamorphic grade towards the interior of the orogen (Haggart et al. 1993; Rivers et al. 1993; Jamieson et al. 1995).”

• cites Haggart et al. 1993 sourceCould not verify

  The Tectonic Interpretation (p. 585) says that fabrics outside shear zones are parallel to those within them, but does not relate their orientation to the Grenville Front. The Introduction discusses the Front and the Parautochthonous Belt without stating that planar fabrics in the belt are generally subparallel to the Front. Searches for front-parallel fabrics and foliation did not establish the claimed relationship. (LLM, conf=0.70)

  Experimental — accuracy not yet measured
• cites Rivers et al. 1993 sourceNot checked — no full text of the source
• cites Jamieson et al. 1995 sourceNot checked — no full text of the source

SL6 includes terranes and domains of the Composite Arc and Frontenac-Adirondack belts.

“In the northwestern part of the Grenville Province in Ontario (Fig. 2), the architecture, metamorphism and interrelationships of terranes and domains have been investigated in detail and the threefold lithotectonic subdivision shown in Fig. 1 has been refined into at least six structural levels (SLs; e.g., Culshaw et al. 1997; Ketchum and Davidson 2000), with the lowest (SL1) being adjacent to the”

• cites Culshaw et al. 1997 sourcePartly supported

  The Figure 2 caption (page unavailable) identifies the Parry Sound domain as originally associated with CMB magmatic arcs, supporting the Composite Arc portion in broad terms. The copy does not identify an SL6 or place Frontenac-Adirondack terranes and domains within it; searches for “SL6” and “Frontenac Adirondack” did not establish those parts of the claim. (LLM, conf=0.78)

  Experimental — accuracy not yet measured
• cites Ketchum and Davidson 2000 sourceNot checked — no full text of the source

Eclogite-facies relics, associated with pods and lenses of ultramafic and anorthositic rocks, are restricted mainly to high-strain zones between and within the terranes and domains.

“Eclogite-facies relics, associated with pods and lenses of ultramafic and anorthositic rocks, are restricted mainly to high-strain zones between and within the terranes and domains (Fig. 2; Davidson 1991, 1998; Culshaw et al. 1997).”

• cites Davidson 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Davidson 1998 sourceNot checked — no full text of the source
• cites Culshaw et al. 1997 sourcePartly supported

  Section 4.5 (page not provided) says relict eclogitic rocks are most common in shear zones, though not confined to them. Section 2.7 says they are commonly associated with anorthosite in major shear zones. The copy does not establish the claimed association with pods and lenses of ultramafic rocks. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Direct dating of metamorphism in HP granulite- and eclogite-facies rocks in Lelukuau and Tshenukutish terranes has yielded ages of 1060-1040 Ma (Ottawa orogeny).

“direct dating of metamorphism in HP granuliteand eclogite-facies rocks has yielded ages of 1060-1040 Ma (Indares et al. 1998), i.e., Ottawa orogeny, compatible with field observations.”

• cites Indares et al. 1998 sourcePartly supported

  Section 4.1 reports a 1049 Ma metamorphic age for Lelukuau, and Section 5.1.3 reports a 1046 Ma age associated with high-pressure metamorphism in western Tshenukutish. But Section 7.2 gives the broader metamorphic-age range for both terranes as 1052–1000 Ma, including a 1027 Ma constraint in eastern Tshenukutish; 1060–1040 Ma is therefore too narrow as a statement of the dating results. The paper does not need to supply the citing authors’ ‘Ottawa orogeny’ interpretation. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Retrogressed eclogite-facies gabbro and associated ultramafic and anorthositic rocks occur in highly strained bodies up to several tens of kilometres long and in tectonically disrupted pods, lenses, and boudins, especially along domain boundaries in the western Grenville Province.

“In the western Grenville Province, as noted earlier, retrogressed eclogite-facies gabbro and associated ultramafic and anorthositic rocks occur in highly strained bodies up to several tens of kilometres long and in tectonically disrupted pods, lenses, and boudins, especially along domain boundaries (Davidson 1991, 1998; Culshaw et al. 1997; Fig. 6A).”

• cites Davidson 1991, 1998Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Culshaw et al. 1997 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

The pre-1300 Ma history of the Laurentian margin is absent in the Composite Arc and Frontenac-Adirondack belts.

“This pre-1300 Ma history of the Laurentian margin is absent in the Composite Arc and Frontenac-Adirondack belts (see also, e.g., Wodicka et al. 1996; Culshaw et al. 1997; Carr et al. 2000).”

• cites Wodicka et al. 1996 sourceNot checked — no full text of the source
• cites Culshaw et al. 1997 sourcePartly supported

  The Geological Setting (section 2.1; page unavailable) distinguishes the pre-1400 Ma Laurentian rocks of the Central Gneiss Belt from the post-1400 Ma composite arc system of the Central Metasedimentary Belt. This supports the distinction for the composite arcs, but the paper does not establish that pre-1300 Ma Laurentian-margin history is absent in the Frontenac-Adirondack belts. (LLM, conf=0.77)

  Experimental — accuracy not yet measured
• cites Carr et al. 2000 sourceNot checked — no full text of the source

Time of normal displacement on the Shawanaga shear zone in cross-section A has been dated at c. 1020 Ma.

“Time of normal displacement has been dated at c45 1020 Ma on Shawanaga shear zone in cross-section A (Culshaw et al. 1997; Ketchum et al. 1998)”

• cites Culshaw et al. 1997 sourcePartly supported

  The paper’s schematic tectonic reconstruction (section 4.5, page unavailable) places extension on the Shawanaga shear zone at approximately 1020 Ma, and its Figure 3 caption describes extensional shear there. It does not establish that the normal displacement itself was directly dated to 1020 Ma; the reconstruction explicitly calls the timing schematic. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites Ketchum et al. 1998 sourceNot checked — no full text of the source

The pattern of northwest-younging displacement and metamorphism is consistent with an overall foreland-(NW-) directed, in-sequence thrust propagation style (understacking) throughout much of the Grenville Province.

“This pattern is consistent with an overall foreland- (NW-) directed, in-sequence thrust propagation style ( understacking in the terminology of Davy and Gillet 1986) throughout much of the Grenville Province (see also Haggart et al. 1993; Rivers et al. 1993; Culshaw et al. 1997).”

• cites Davy and Gillet 1986 sourceNot checked — no full text of the source
• cites Haggart et al. 1993 sourcePartly supported

  The Introduction reports NW-directed thrusting along the entire Grenville Front, and the Tectonic Interpretation describes a shear zone migrating toward the foreland near Killarney. But the Introduction says the timing of deformation may differ from place to place; the paper does not establish northwest-younging, in-sequence thrust propagation throughout much of the Grenville Province. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites Rivers et al. 1993 sourceNot checked — no full text of the source

The Paleoproterozoic lower crust underlying the southern Parautochthonous belt in the western Grenville Province was unusually ductile during the Ottawa orogeny, leading to widespread distributed flow in gneissic rocks during both compressional and extensional tectonism.

“In addition, the Paleoproterozoic lower crust underlying the southern Parautochthonous belt in the western Grenville Province was unusually ductile during the Ottawa orogeny, leading to widespread distributed flow in gneissic rocks during both compressional and extensional tectonism (Fig. 12C; Culshaw et al. 1994, 1997; Ketchum et al. 1998).”

• cites Culshaw et al. 1994 sourceNot checked — no full text of the source
• cites Culshaw et al. 1997 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites Ketchum et al. 1998 sourceNot checked — no full text of the source

Early Ottawan out-of-sequence thrusting of the terranes overlying the HP belt occurred in the western Grenville Province.

“early Ottawan out-of-sequence thrusting of the terranes overlying the HP belt in the western Grenville Province”

• cites Culshaw et al. 1997 sourceSupported
• cites Wodicka et al. 2000 sourceNot checked — no full text of the source

In the central Grenville Province, HP rocks underwent a single stage of unroofing with transport into the upper crust by c. 1020 Ma.

“In the central Grenville Province, HP rocks formed at c45 1060-1040 Ma and underwent a single stage of unroofing with transport into the upper crust by c45 1020 Ma, whereas farther west they underwent two stages of unroofing separated by penetrative mid-crustal recrystallization before transport to the upper crust at c45 1020 Ma.”

In the central Grenville Province, HP rocks formed at c. 1060-1040 Ma.

“In the central Grenville Province, HP rocks formed at c45 1060-1040 Ma and underwent a single stage of unroofing with transport into the upper crust by c45 1020 Ma, whereas farther west they underwent two stages of unroofing separated by penetrative mid-crustal recrystallization before transport to the upper crust at c45 1020 Ma.”

HP rocks occur along the interface between the Parautochthonous and Allochthonous belts.

“it is clear from Fig. 1 that they occur along the interface between the Parautochthonous and Allochthonous belts.”

The HP belt is characterized by Grenvillian eclogite and co-facial HP granulite in mafic rocks.

“The HP belt is developed in Paleo- and Mesoproterozoic rocks of the pre-Grenvillian Laurentian margin and characterized by Grenvillian eclogite and co-facial HP granulite in mafic rocks.”

In the central Grenville Province, thrusting and extension were coeval.

“In detail, thrusting episodes preceded extension in the western Grenville Province, whereas in the central Grenville Province, they were coeval, resulting in unroofing by tectonic extrusion.”

Pressure-temperature estimates for eclogite-facies conditions in well-preserved assemblages are about 1800 MPa and 850°C.

“Pressure-temperature ( P-T ) estimates for eclogite-facies conditions in well-preserved assemblages are about 1800 MPa and 850°C.”

In the western Grenville Province, thrusting episodes preceded extension.

“In detail, thrusting episodes preceded extension in the western Grenville Province, whereas in the central Grenville Province, they were coeval, resulting in unroofing by tectonic extrusion.”

In the central Grenville Province, the footwall ramp is well preserved.

“In the central Grenville Province, the footwall ramp is well preserved, but any former ramp in the western Grenville Province was obliterated by later lower crustal extensional flow.”

The HP belt is sandwiched between two belts of Laurentian crust that experienced very different styles and intensities of Grenvillian structural and metamorphic reworking.

“Figure 1 shows that the HP belt is sandwiched between two belts of Laurentian crust that experienced very different styles and intensities of Grenvillian structural and metamorphic reworking.”

Several major compressional structures visible on some of the cross-sections were subsequently variably overprinted in extension.

“Several major compressional structures visible on some of these sections were subsequently variably overprinted in extension.”

The HP belt is developed in Paleo- and Mesoproterozoic rocks of the pre-Grenvillian Laurentian margin.

“The HP belt is developed in Paleo- and Mesoproterozoic rocks of the pre-Grenvillian Laurentian margin and characterized by Grenvillian eclogite and co-facial HP granulite in mafic rocks.”

The pattern of deep crustal seismic reflection in the Lithoprobe ECSOOT line contrasts with that farther west.

“However, the pattern of deep crustal seismic reflection in the Lithoprobe Eastern Canadian Shield Onshore-Offshore Transect (ECSOOT) line contrasts with that father west, suggesting that, if present, the HP rocks were exhumed by a different mechanism.”

The upper boundary of the HP belt is marked by a system of shear zones with normal-sense displacement.

“The upper boundary is marked by a system of shear zones with normal-sense displacement.”

Farther west, HP rocks underwent two stages of unroofing separated by penetrative mid-crustal recrystallization before transport to the upper crust at c. 1020 Ma.

“In the central Grenville Province, HP rocks formed at c45 1060-1040 Ma and underwent a single stage of unroofing with transport into the upper crust by c45 1020 Ma, whereas farther west they underwent two stages of unroofing separated by penetrative mid-crustal recrystallization before transport to the upper crust at c45 1020 Ma.”

Known occurrences of HP rocks of Grenvillian age are c45 30-150 km from the Grenville Front, the northwestern margin of the Grenville Province.

“Known occurrences of HP rocks of Grenvillian age are c45 30-150 km from the Grenville Front, the northwestern margin of the Grenville Province (Fig. 1).”

The Algonquin metagabbro is characterized by complex coronas of orthopyroxene, clinopyroxene, and garnet-clinopyroxene symplectite, separating olivine and plagioclase.

“The metagabbro is characterized by complex coronas of orthopyroxene, clinopyroxene, and garnet-clinopyroxene symplectite, separating olivine and plagioclase.”

The HP terranes lack Sudbury metadiabase.

“The HP terranes lack Sudbury metadiabase, but are characterized by the presence of the 1170-1150 Ma, coronitic Algonquin metagabbro (Davidson and van Breemen 1988; Heaman and LeCheminant 1993) and by pods and lenses of retrogressed eclogite with protolith ages of c45 1470-1403 Ma (Indares and Dunning 1997; Ketchum and Krogh 1997, 1998).”

The HP terranes appear to lack units of Archean age.

“The HP terranes, which appear to lack units of Archean age, consist of Paleo- and Mesoproterozoic metagranitoid rocks emplaced during two magmatic episodes at c45 1715-1600 and c45 1470-1430 Ma (Krogh 1991; Nadeau and van Breemen 1998; Ketchum and Davidson 2000).”

Several of the U/Pb ages overlap with the timing of the granulite-facies overprint.

“it is undeniable that several of the ages overlap with the timing of the granulite-facies overprint”

There is no evidence for a high-temperature (amphibolite-facies or higher) Grenvillian metamorphic overprint in Lac Joseph terrane, except at the structural base of the terrane.

“There is no evidence for a high-temperature (amphibolite-facies or higher) Grenvillian metamorphic overprint, except at the structural base of the terrane.”

The HP belt is composed of units of Paleo- and Mesoproterozoic age.

“(2) The HP belt is composed of units of Paleoand Mesoproterozoic age.”

In the central Grenville Province, the metaigneous bodies with HP assemblages preserve recognizable aspects of their original intrusive shapes, albeit strongly modified by folding and ductile shearing.

“In the central Grenville Province, the metaigneous bodies with HP assemblages preserve recognizable aspects of their original intrusive shapes, albeit strongly modified by folding and ductile shearing.”

The Frontenac-Adirondack boundary thrust zone is a moderately southeast-dipping, amphibolite-facies shear zone that juxtaposes the Frontenac-Adirondack belt in its hanging wall over a footwall composed of the Composite Arc belt in the west and the HP and LP belts farther east.

“The Frontenac-Adirondack boundary thrust zone is a moderately southeast-dipping, amphibolite-facies shear zone that juxtaposes the Frontenac-Adirondack belt in its hanging wall over a footwall composed of the Composite Arc belt in the west and the HP and LP belts farther east”

Retrogressed eclogite is restricted to the HP belt.

“whereas retrogressed eclogite is restricted to the HP belt (Fig. 8A).”

Tshenukutish terrane (HP belt) and Hart Jaune terrane (LP belt) both carry evidence for Pinwarian magmatism and metamorphism.

“(7) Tshenukutish terrane (HP belt) and Hart Jaune terrane (LP belt) both carry evidence for Pinwarian magmatism and metamorphism (Fig. 8B).”

In the central Grenville Province, maximum estimated conditions are in the ranges 1700 to 1900 MPa and 850 to 925°C.

“where maximum estimated conditions are in the ranges 1700 to 1900 MPa and 850 to 925°C.”

The Allochthon Boundary thrust is the site of an important, although locally cryptic, break in metamorphic grade, bringing the HP terranes in its hanging wall into contact with amphibolite-facies gneisses of the Parautochthonous belt in its footwall.

“It is the site of an important, although locally cryptic, break in metamorphic grade, bringing the HP terranes in its hanging wall into contact with amphibolite-facies gneisses of the Parautochthonous belt in its footwall.”

In the central Grenville Province, HP metamorphism took place during the Ottawa orogeny at ~1060-1040 Ma.

“In the central Grenville Province, HP metamorphism took place during the Ottawa orogeny at c45 1060-1040 Ma.”

Molson Lake terrane (HP belt) and Lac Joseph terrane (LP belt) both carry evidence for Labradorian magmatism and metamorphism.

“Similarly, both Molson Lake terrane (HP belt) and Lac Joseph terrane (LP belt) carry evidence for Labradorian magmatism and metamorphism (Fig. 8C).”

Some samples preserve evidence of a former eclogite-facies assemblage consisting of garnet-omphacite-kyanite, indicated by symplectite textures.

“For instance, clinopyroxene-plagioclase symplectite replaces presumed former omphacite; pyrope-rich garnet is surrounded by decompression collars of plagioclase-pargasite symplectite; and kyanite relics are surrounded by a symplectic intergrowth of corundum-hercynite ± sapphirine, pointing to a former assemblage consisting of garnet-omphacite-kyanite in some samples.”

• cites Davidson 1991, 1998Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Indares and Dunning 1997 sourceNot checked — no full text of the source

The Composite Arc boundary thrust zone consists of anastomosing belts of amphibolite-facies mylonite and highly strained gneiss that surround lenses and boudins of less deformed orthogneiss.

“It consists of anastomosing belts of amphibolite-facies mylonite and highly strained gneiss that surround lenses and boudins of less deformed orthogneiss (e.g., Hanmer 1988).”

• cites Hanmer 1988 sourceNot checked — no full text of the source

Retrogression was generally less pervasive in the central Grenville Province.

“Furthermore, retrogression was generally less pervasive in the central Grenville Province”

The upper boundary of the HP belt in cross-sections D and E is marked by the Upper Allochthon thrust.

“and in cross-sections D and E by the Upper Allochthon thrust”

Fe-Ti gabbro, of similar age to the Algonquin gabbro, occurs in Tshenukutish terrane.

“(5) Fe-Ti gabbro, of similar age to the Algonquin gabbro, occurs in Tshenukutish terrane (Figs. 8A, 8B).”

In cross-section D, the thrust-sense Highway shear zone carries rocks in its hanging wall that were metamorphosed at c. 1011-989 Ma.

“In cross-section D, the thrust-sense Highway shear zone carries rocks in its hanging wall that were metamorphosed at c45 1011-989 Ma (Hynes et al. 2000).”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

Geochronological data from hanging wall rocks indicate that major displacement on the Allochthon Boundary thrust occurred during the Ottawa orogeny at c. 1080-1040 Ma.

“Geochronological data from hanging wall rocks indicate that major displacement on the Allochthon Boundary thrust occurred during the Ottawa orogeny at c45 1080-1040 Ma.”

The dated time of displacement on the major contractional shear zones appears to young generally towards the northwest of the Grenville orogen.

“In summary, the dated time of displacement on the major contractional shear zones appears to young generally towards the northwest of the Grenville orogen.”

Retrogressed eclogite-facies mafic units are tectonically disaggregated and occur in pods, boudins, and pulled apart intrusions as a result of pervasive ductile flow of the HP terrane.

“Retrogressed eclogite-facies mafic units are tectonically disaggregated and occur in pods, boudins, and pulled apart intrusions as a result of pervasive ductile flow of the HP terrane.”

In both the western and central parts of the HP belt, preserved and relict eclogite-facies assemblages are restricted largely to mafic plutonic rocks.

“In both the western and central parts of the HP belt, preserved and relict eclogite-facies assemblages are restricted largely to mafic plutonic rocks.”

The Composite Arc boundary thrust zone is a 7-12 km thick, southeast-dipping, ductile thrust zone that separates the HP belt (and Muskoka domain) in its footwall from the Composite Arc belt in its hanging wall.

“The Composite Arc boundary thrust zone is a 7-12 km thick, southeast-dipping, ductile thrust zone that separates the HP belt (and Muskoka domain) in its footwall from the Composite Arc belt in its hanging wall.”

The Allochthon Boundary thrust is characterized in the field by a zone of amphibolite-facies straight gneiss up to a kilometre wide.

“The Allochthon Boundary thrust is characterized in the field by a zone of amphibolite-facies straight gneiss up to a kilometre wide.”

Archean rocks are restricted to the footwall (Parautochthonous belt) of the HP belt in all sections.

“(1) Archean rocks are restricted to the footwall (Parautochthonous belt) of the HP belt in all sections.”

Algonquin metagabbro occurs in both the HP belt and Muskoka domain.

“(4) Algonquin metagabbro occurs in both the HP belt and Muskoka domain”

Shabogamo gabbro occurs in both the Parautochthonous and HP belts in western Labrador.

“but occurs in both the Parautochthonous and HP belts in western Labrador (Figs. 8B, 8C).”

Grenvillian displacement on the Grenville Front is dated at c. 1005-995 Ma, i.e., Rigolet orogeny.

“Timing of the Grenvillian displacement on the Grenville Front has been dated at c45 1005-995 Ma (e.g., Krogh 1994), i.e., Rigolet orogeny.”

• cites Krogh 1994 sourceNot checked — no full text of the source

The Parautochthonous, HP, and LP belts exhibit profound contrasts in their Grenvillian metamorphic history, both in terms of the time and grade of metamorphism.

“In contrast to the many shared elements of their pre-Grenvillian history, the Parautochthonous, HP, and LP belts exhibit profound contrasts in their Grenvillian metamorphic history, both in terms of the time (Fig. 8) and grade of metamorphism.”

Archean rocks have not been recognized in the HP or LP terranes.

“They have not been recognized in the HP or LP terranes.”

The upper boundary of the HP belt in cross-sections A and C is marked by the Composite Arc boundary thrust zone and the Frontenac-Adirondack boundary thrust zone.

“The upper boundary of the HP belt in cross-sections A and C is marked by the Composite Arc boundary thrust zone and the Frontenac-Adirondack boundary thrust zone”

Garnet in these rocks pseudomorphs igneous plagioclase.

“Garnet in these rocks pseudomorphs igneous plagioclase (Fig. 7C).”

Decompression-retrogression reactions were more pervasive in the western Grenville Province than in the central Grenville Province.

“Decompression-retrogression reactions were more pervasive in the western Grenville Province, where it has not been possible to determine reliable estimates of peak P-T metamorphic conditions, than in the central Grenville Province”

The dyke-like shapes of bodies of Shabogamo gabbro are still evident.

“For example, the dyke-like shapes of bodies of Shabogamo gabbro are still evident (Fig. 6B).”

Rocks of Paleo- and Mesoproterozoic age also occur in both the Parautochthonous belt and the LP belt.

“Rocks of this age also occur in both the Parautochthonous belt and the LP belt (Figs. 8A, 8C).”

In the western Grenville Province, the HP rocks underwent penetrative granulite-facies recrystallization from ~1080 to 1060 Ma (Ottawa orogeny).

“In contrast, in the western Grenville Province, where the HP metamorphism occurred earlier but is less well dated, the HP rocks were subsequently transported into the mid-crust, where they were imbricated with Muskoka domain and underwent penetrative granulite-facies recrystallization from c45 1080 to 1060 Ma (Ottawa orogeny).”

Individual bodies of Algonquin metagabbro vary from pods and lenses to elongate forms from a few metres to over a kilometres in the longest dimension.

“Individual bodies vary from pods and lenses to elongate forms from a few metres to over a kilometres in the longest dimension.”

Sudbury diabase is restricted to the Parautochthonous belt.

“(3) Sudbury diabase is restricted to the Parautochthonous belt (Fig. 8A).”

In the western Grenville Province, it has not been possible to determine reliable estimates of peak P-T metamorphic conditions.

“where it has not been possible to determine reliable estimates of peak P-T metamorphic conditions”

In both western and central Grenville Province, the most widespread Grenvillian metamorphism in the parautochthonous terranes in the footwall of the HP belt took place in a short-lived event from ~1010-990 Ma during the Rigolet orogeny.

“They show that in both regions the most widespread Grenvillian metamorphism in the parautochthonous terranes in the footwall of the HP belt took place in a short-lived event from c45 1010-990 Ma during the Rigolet orogeny.”

During unroofing, HP rocks were variably retrogressed to granulite- and amphibolite-facies assemblages.

“During unroofing, HP rocks were variably retrogressed to granuliteand amphibolite-facies assemblages.”

The general geometry of the detachment systems is that they are gently to moderately southeast-dipping structures that become listric towards the southeast and sole out at or slightly above the Moho.

“The general geometry of the detachment systems that emerges from Fig. 10 is that they are gently to moderately southeast-dipping structures that become listric towards the southeast and sole out at or slightly above the Moho.”

In cross-sections B, C, D, and E, a ramp-flat geometry is well developed.

“In cross-sections B, C, D, and E, a ramp-flat geometry is well developed.”

The HP belt retains an internal structural and metamorphic coherence that can be documented from the outcrop patterns of mafic dykes, despite ductile deformation and penetrative recrystallization.

“Although ductilely deformed and penetratively recrystallized, the HP belt retains an internal structural and metamorphic coherence that can be documented from the outcrop patterns of mafic dykes.”

In cross-section A, there is widespread evidence of Ottawan (c. 1060-1020 Ma) metamorphism in the southern Parautochthonous belt prior to reworking during the Rigolet orogeny.

“In cross-section A, there is widespread evidence of Ottawan ( c45 1060-1020 Ma) metamorphism in the southern Parautochthonous belt prior to reworking during the Rigolet orogeny (Jamieson et al, 1995)”

• cites Jamieson et al, 1995 sourceNot checked — no full text of the source

There is no such gravity anomaly in the western Grenville Province.

“whereas there is no such gravity anomaly in the western Grenville Province (e.g., Rivers et al. 1989; Hynes 1994).”

• cites Rivers et al. 1989 sourceNot checked — no full text of the source
• cites Hynes 1994 sourceNot checked — no full text of the source

In cross-section C, the time of ramp formation is uncertain.

“However, in cross-section C, the time of ramp formation is uncertain (Martignole et al. 2000).”

• cites Martignole et al. 2000 sourceNot checked — no full text of the source

There is a negative gravity anomaly, the Grenville Front gravity low, under the Parautochthonous belt in the central Grenville Province.

“(9) There is a negative gravity anomaly, the Grenville Front gravity low, under the Parautochthonous belt in the central Grenville Province”

• cites Rivers et al. 1989 sourceNot checked — no full text of the source
• cites Hynes 1994 sourceNot checked — no full text of the source

In cross-section C, evidence of Ottawan metamorphism in the southern Parautochthonous belt is more limited than in cross-section A.

“whereas in C the evidence is more limited (see Fig. 4)”

In the western Grenville Province, the footwall beneath the HP belt was deformed by penetrative ductile flow during the Ottawa orogeny.

“(3) In the western Grenville Province, the footwall beneath the HP belt was deformed by penetrative ductile flow during the Ottawa orogeny”

In cross-section E, there is a marked contrast in Ottawan metamorphic grade across the Allochthon Boundary detachment.

“However, in cross-section E, the marked contrast in Ottawan metamorphic grade across the Allochthon Boundary detachment”

In contrast to regional-scale lower-crustal extension, extensional structures higher in the structural pile are discrete and vary in character, timing, and significance.

“In contrast to these examples of regional-scale lower-crustal extension, extensional structures higher in the structural pile are discrete and vary in character, timing, and significance.”

Displacement on the northwest-dipping Carthage-Colton mylonite zone, which marks the boundary between Frontenac and Adirondack terranes, has been dated at c. 1000-930 Ma.

“whereas displacement on the northwest-dipping Carthage-Colton mylonite zone, which marks the boundary between Frontenac and Adirondack terranes, has been dated at c45 1000-930 Ma (McLelland et al. 1996; Magloughlin et al. 1997).”

• cites McLelland et al. 1996 sourceNot checked — no full text of the source
• cites Magloughlin et al. 1997Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Displacement on the Lac Émérillon shear zone in cross-section E has been dated at 990 Ma.

“and on Lac Émérillon shear zone (cross-section E), it has been dated at 990 Ma (Connelly et al. 1995).”

• cites Connelly et al. 1995 sourceNot checked — no full text of the source

HP metamorphism took place at c45 1060-1040 Ma in the central Grenville Province.

“(1) HP metamorphism took place at c45 1060-1040 Ma in the central Grenville Province”

Major southeast-dipping normal faults occur in all the cross-sections.

“Major southeastdipping normal faults occur in all the cross-sections”

The Allochthon Boundary detachment system comprises several normal-sense shear zones that are known in cross-sections A, C, D, and E.

“The Allochthon Boundary detachment system comprises several normal-sense shear zones that are known in cross-sections A, C, D, and E.”

There is a significant change in the two-dimensional architecture of the HP belt along the length of the Grenville orogen.

“Fig. 9 illustrates that there is a significant change in the two-dimensional architecture of the HP belt along the length of the Grenville orogen.”

The HP belt had already been transported into the mid- to upper crust by late Ottawan time, the time of earliest displacement on the detachment systems.

“As noted earlier, the HP belt had already been transported into the mid- to upper crust by late Ottawan time, the time of earliest displacement on the detachment systems.”

All three detachment systems are ductile structures characterized by amphibolite-facies mineral assemblages.

“All are ductile structures characterized by amphibolite-facies mineral assemblages.”

Time of displacement on the Lac Émérillon and Hart Jaune shear zones has been dated at c. 990 Ma.

“Time of displacement on the Lac Émérillon and Hart Jaune shear zones has been dated at c45 990 Ma (Scott and Hynes 1994; Connelly et al. 1995).”

• cites Scott and Hynes 1994Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Connelly et al. 1995 sourceNot checked — no full text of the source

Transport of HP terranes to mid- to upper crustal levels had taken place by late Ottawan time in both the western and central Grenville Province.

“(8) Transport of HP terranes to mid- to upper crustal levels had taken place by late Ottawan time in both the western and central Grenville Province.”

In cross-section A, the HP belt dips relatively uniformly into the lower crust.

“In contrast, in cross-section A, the HP belt dips relatively uniformly into the lower crust.”

In cross-section B, the leading, northwestern edge of a flat is present in a klippe at the southeast end of the cross-section.

“In B, the leading, northwestern edge of a flat is present in a klippe at the southeast end of the cross-section (Fig. 9)”

Displacement on the Relay-Tshenukutish shear zone in the vicinity of cross-section D has been dated at 1017-1007 Ma.

“Displacement on the Relay-Tshenukutish shear zone in the vicinity of cross-section D has been dated at 1017-1007 Ma (Cox et al. 1998)”

• cites Cox et al. 1998 sourceNot checked — no full text of the source

In cross-section D, the Hart Jaune shear zone is located in the immediate hanging wall of the HP belt.

“In cross-section D, Hart Jaune shear zone is located in the immediate hanging wall of the HP belt.”

The transfer of the HP belt from the base of the lower crust to the mid- to upper crust in an understacking regime is common to both the western and central Grenville Province.

“the transfer of the HP belt from the base of the lower crust to the mid- to upper crust in an understacking regime is common to both the western and central Grenville Province”

The timing of the transfer of the HP belt from the base of the lower crust to the mid- to upper crust was slightly different in the western and central Grenville Province.

“although the timing was slightly different in the two areas”

An important phase of extensional displacement along southeast-dipping detachments followed uplift of the HP belt onto its footwall in a compressional regime during the Ottawa orogeny.

“Following uplift of the HP belt onto its footwall in a compressional regime during the Ottawa orogeny, there is evidence for an important phase of extensional displacement along southeast-dipping detachments (Fig. 12C).”

HP metamorphism was somewhat earlier in the western Grenville Province than in the central Grenville Province.

“it was somewhat earlier in the western Grenville Province”

Final transport of the HP rocks into the upper crust occurred in late Ottawan time, c. 1020 Ma.

“with final transport into the upper crust occurring in late Ottawan time ( c45 1020 Ma)”

The relict eclogite in the western Grenville Province occurs in rocks that subsequently underwent Ottawan upper amphibolite- to granulite-facies metamorphism at c. 1080-1060 Ma.

“It can be seen in Fig. 4 that the relict eclogite in the western Grenville Province occurs in rocks that subsequently underwent Ottawan upper amphibolite- to granulite-facies metamorphism at c45 1080-1060 Ma.”

The two-stage uplift-exhumation path was separated by a period of mid-crustal residence and granulite-facies metamorphism at c. 1180-1160 Ma.

“separated by a period of mid-crustal residence and granulite-facies metamorphism at c45 1180-1160 Ma”

Maximum P-T conditions of the eclogite-facies rocks, estimated from samples in the central Grenville Province, are about 1800 MPa and 850°C.

“Maximum P-T conditions of the eclogite-facies rocks, estimated from samples in the central Grenville Province, are about 1800 MPa and 850°C.”

During the late Ottawa orogeny (~1020 Ma), the HP belt was uplifted to upper crust in both areas.

“C. Late Ottawa orogeny: ~1020 Ma. Uplift of HP belt to upper crust in both areas.”

The HP rocks subsequently underwent a two-stage uplift-exhumation path.

“The HP rocks subsequently underwent a two-stage uplift-exhumation path”

Evidence exists for out-of-sequence imbrication of Muskoka domain with the HP Algonquin terrane at this time.

“This notion is supported by the evidence for out-of-sequence imbrication of Muskoka domain with the HP Algonquin terrane at this time.”

HP metamorphism in the western Grenville Province has not yet been satisfactorily dated despite detailed study.

“but has not yet been satisfactorily dated despite detailed study.”

The HP rocks comprise principally eclogite and co-facial HP granulite.

“The HP rocks comprise principally eclogite and co-facial HP granulite”

The transfer of the HP belt from the base of the lower crust to the mid- to upper crust was interrupted in the western Grenville Province by a period of mid-crustal residence.

“the process was interrupted in the western Grenville Province by a period of mid-crustal residence”

In rocks that underwent penetrative strain during their exhumation, the early record was more or less completely obliterated, largely restricting preserved HP assemblages to competent dry units, such as metagabbro.

“In rocks that underwent penetrative strain during their exhumation, this early record was more or less completely obliterated, largely restricting preserved HP assemblages to competent dry units, such as metagabbro.”

On a regional scale, there is little evidence for large-scale out-of-sequence thrusting by overstacking behind, to the southeast of, the HP rocks.

“On a regional scale, there is little evidence for large-scale out-of-sequence thrusting by overstacking behind (to the southeast of) the HP rocks”

At approximately the same time that the eclogite-facies rocks in the western Grenville Province were undergoing mid-crustal granulite-facies recrystallization, eclogites were forming in the deep crust in the central Grenville Province.

“At approximately the same time that the eclogite-facies rocks in the western Grenville Province were undergoing mid-crustal granulite-facies recrystallization, eclogites were forming in the deep crust in the central Grenville Province”

The Archean craton does not penetrate as far into the orogen at mid-crustal levels in cross-section A as elsewhere.

“As noted earlier, the Archean craton does not penetrate as far into the orogen at mid-crustal levels in cross-section A, as elsewhere.”

In the central Grenville Province, HP metamorphism was followed by a single stage of uplift into the upper crust by late Ottawan time.

“It was followed by a single stage of uplift into the upper crust by late Ottawan time.”

In the central Grenville Province, thrusting and extensional shearing were approximately coeval.

“in the central Grenville Province, thrusting and extensional shearing were approximately coeval”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

Eclogite-facies rocks have not been positively identified in the eastern Grenville Province.

“Eclogite-facies rocks have not been positively identified in the eastern Grenville Province”

Recognizable evidence for the eclogite-facies stage in the central Grenville Province is preserved in thrust fabrics, eclogite-facies mineral assemblages, growth-zoning patterns in slow-diffusing porphyroblastic minerals such as garnet, and U/Pb ages in accessory minerals.

“Recognizable evidence for this stage is preserved in thrust fabrics, eclogite-facies mineral assemblages, growth-zoning patterns in slow-diffusing porphyroblastic minerals such as garnet, and U/Pb ages in accessory minerals.”

In the central Grenville Province, extension took place above the HP belt.

“extension took place above the HP belt”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

Late extensional shear zone systems developed across the orogen, from the Mid-Parautochthon detachment in the northwest to the Carthage-Colton mylonite zone in the southeast.

“Late extensional shear zone systems develop across orogen, from Mid-Parautochthon detachment (M-PD) in northwest to Carthage-Colton mylonite zone (CCMZ) in southeast.”

HP metamorphism took place at c. 1060-1040 Ma in the central Grenville Province.

“The HP metamorphism took place at c45 1060-1040 Ma in the central Grenville Province”

• Also stated in: § Conclusions · p. 24 · plain

  “in the central Grenville Province, HP metamorphism is dated at c45 1060-1040 Ma (Ottawa orogeny)”

Several important systems of crustal-scale, ductile detachments have been identified that may have exerted a secondary control on unroofing.

“several important systems of crustal-scale, ductile detachments have been identified that may have exerted a secondary control.”

The northwestern part of the Parautochthonous belt, known as the Grenville Front tectonic zone (GFTZ), is characterized by front-parallel structures with dip-parallel lineations.

“The northwestern part of the belt, known as the Grenville Front tectonic zone (GFTZ), is characterized by front-parallel structures with dip-parallel lineations, and the various domains and terranes of the Parautochthonous belt are linked lithologically to the foreland and each other by the presence of deformed mafic dykes belonging to, or having chemical affinities with, the c45 1235 Ma Sudbury”

• cites Krogh et al. 1987Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Dudás et al. 1994 sourceNot checked — no full text of the source
• cites Indares and Dunning 1997 sourceNot checked — no full text of the source

In the region shown in Fig. 2, the Parautochthonous belt (SL1 of Ketchum and Davidson 2000) comprises the reworked continuation of the adjacent Archean Superior Province and variably gneissic granitoid intrusions and subordinate metasediments of late Paleoproterozoic to Mesoproterozoic age.

“In the region shown in Fig. 2, the Parautochthonous belt (SL1 of Ketchum and Davidson 2000) comprises the reworked continuation of the adjacent Archean Superior Province and variably gneissic granitoid intrusions and subordinate metasediments of late Paleoproterozoic to Mesoproterozoic age (e.g., Easton 1992).”

• cites Easton 1992Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The arc and (or) back-arc terranes comprising the Composite Arc belt were assembled outboard of Laurentia at c45 1250-1225 Ma during the Elzevirian orogeny, shortly before their accretion to Laurentia.

“This nomenclature reflects current understanding that the arc and (or) back-arc terranes comprising the Composite Arc belt were assembled outboard of Laurentia at c45 1250-1225 Ma during the Elzevirian orogeny, shortly before their accretion to Laurentia (see also Rivers 1997; Corriveau and van Breemen 2000; Rivers and Corrigan 2000; Hanmer et al. 2000).”

• cites Rivers 1997 sourceNot checked — no full text of the source
• cites Corriveau and van Breemen 2000 sourceNot checked — no full text of the source
• cites Rivers and Corrigan 2000 sourceNot checked — no full text of the source

The continuity of the Parautochthonous, HP, and LP belts and their structural boundaries implies that there is a broad coherence to the orogen at this scale.

“The continuity of the Parautochthonous, HP, and LP belts and their structural boundaries (Fig. 1) implies that there is a broad coherence to the orogen at this scale.”

If HP rocks are present in the eastern Grenville Province, they were exhumed by a different mechanism.

“However, the pattern of deep crustal seismic reflection in the Lithoprobe Eastern Canadian Shield Onshore-Offshore Transect (ECSOOT) line contrasts with that father west, suggesting that, if present, the HP rocks were exhumed by a different mechanism.”

The Parautochthonous belt is composed of lithologic units that locally can be correlated with less deformed and metamorphosed equivalent units in the foreland to the northwest of the orogen.

“The Parautochthonous belt, the lowest structural unit in the Grenville Province, is composed of lithologic units that locally can be correlated with less deformed and metamorphosed equivalent units in the foreland to the northwest of the orogen.”

The various domains and terranes of the Parautochthonous belt are linked lithologically to the foreland and each other by the presence of deformed mafic dykes belonging to, or having chemical affinities with, the c45 1235 Ma Sudbury swarm.

“The northwestern part of the belt, known as the Grenville Front tectonic zone (GFTZ), is characterized by front-parallel structures with dip-parallel lineations, and the various domains and terranes of the Parautochthonous belt are linked lithologically to the foreland and each other by the presence of deformed mafic dykes belonging to, or having chemical affinities with, the c45 1235 Ma Sudbury”

• cites Krogh et al. 1987Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Dudás et al. 1994 sourceNot checked — no full text of the source
• cites Indares and Dunning 1997 sourceNot checked — no full text of the source

In the western Grenville Province, any former ramp was obliterated by later lower crustal extensional flow.

“In the central Grenville Province, the footwall ramp is well preserved, but any former ramp in the western Grenville Province was obliterated by later lower crustal extensional flow.”

HP rocks form a continuous or semi-continuous belt along the orogen.

“From the distribution of HP rocks in Fig. 1, we infer that they also form a continuous or semi-continuous belt along the orogen.”

The lower boundary of the HP belt is the Allochthon Boundary thrust.

“The lower boundary, known as the Allochthon Boundary thrust, was originally defined by Rivers et al. (1989), although its precise location has been revised slightly in Fig. 1 (see figure caption for details).”

• cites Rivers et al. (1989) sourceNot checked — no full text of the source

Leucosome development in adjacent migmatitic gneisses well records the granulite-facies metamorphism.

“This event is well recorded by leucosome development in adjacent migmatitic gneisses (Bussy et al. 1995).”

• cites Bussy et al. 1995 sourceNot checked — no full text of the source

The HP terranes are characterized by the presence of the 1170-1150 Ma, coronitic Algonquin metagabbro.

“The HP terranes lack Sudbury metadiabase, but are characterized by the presence of the 1170-1150 Ma, coronitic Algonquin metagabbro (Davidson and van Breemen 1988; Heaman and LeCheminant 1993) and by pods and lenses of retrogressed eclogite with protolith ages of c45 1470-1403 Ma (Indares and Dunning 1997; Ketchum and Krogh 1997, 1998).”

• cites Davidson and van Breemen 1988 sourceNot checked — no full text of the source
• cites Heaman and LeCheminant 1993 sourceNot checked — no full text of the source

Following the HP event, the HP belt in the western Grenville Province underwent a period of mid-crustal granulite-facies metamorphism in which the eclogite-facies assemblages were partly recrystallized.

“following the HP event, the HP belt in the western Grenville Province underwent a period of mid-crustal granulite-facies metamorphism in which the eclogite-facies assemblages were partly recrystallized.”

• cites Bussy et al. 1995 sourceNot checked — no full text of the source

The mutually exclusive geographic distributions of Sudbury metadiabase in the Parautochthonous belt and Algonquin metagabbro and retrogressed eclogite relics in the HP belt have proved to be a useful tool for delineation of the boundary between the two belts in the field.

“The mutually exclusive geographic distributions of Sudbury metadiabase in the Parautochthonous belt and Algonquin metagabbro and retrogressed eclogite relics in the HP belt have proved to be a useful tool for delineation of the boundary between the two belts in the field (Ketchum and Davidson 2000).”

• cites Ketchum and Davidson 2000 sourceNot checked — no full text of the source

Many of the U/Pb results from relict eclogite bodies are not open to unequivocal interpretation.

“Unfortunately, many of these results are not open to unequivocal interpretation.”

HP metamorphism in Lelukuau and Tshenukutish terranes postdated 1170 Ma.

“This implies that HP metamorphism postdated 1170 Ma, and direct dating of metamorphism in HP granuliteand eclogite-facies rocks has yielded ages of 1060-1040 Ma (Indares et al. 1998), i.e., Ottawa orogeny, compatible with field observations.”

Paleo- and Mesoproterozoic units in Gagnon terrane display evidence for a single metamorphism dated at about 1000 Ma (Rigolet orogeny).

“Paleo- and Mesoproterozoic units in Gagnon terrane display evidence for a single metamorphism that has been dated at about 1000 Ma (Connelly and Heaman 1993; Connelly et al. 1995; Schwarz 1998), i.e., Rigolet orogeny.”

• cites Connelly and Heaman 1993 sourceNot checked — no full text of the source
• cites Connelly et al. 1995 sourceNot checked — no full text of the source
• cites Schwarz 1998Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The Algonquin gabbro could have undergone a short-lived HP event that is not recorded in the major silicate mineralogy or the U/Pb systematics of zircon and baddeleyite.

“and so, by extension, it could have undergone a short-lived HP event that is not recorded in the major silicate mineralogy or the U/Pb systematics of zircon and baddeleyite.”

The HP terranes are characterized by pods and lenses of retrogressed eclogite with protolith ages of c45 1470-1403 Ma.

“The HP terranes lack Sudbury metadiabase, but are characterized by the presence of the 1170-1150 Ma, coronitic Algonquin metagabbro (Davidson and van Breemen 1988; Heaman and LeCheminant 1993) and by pods and lenses of retrogressed eclogite with protolith ages of c45 1470-1403 Ma (Indares and Dunning 1997; Ketchum and Krogh 1997, 1998).”

• cites Indares and Dunning 1997 sourceNot checked — no full text of the source
• cites Ketchum and Krogh 1997, 1998Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Molson Lake terrane is now considered part of the HP belt on the basis of its metamorphic signature.

“Molson Lake terrane, formerly included in the Parautochthonous belt by Rivers et al. (1989), is now considered part of the HP belt on the basis of its metamorphic signature (see caption, Fig. 1).”

• cites Rivers et al. 1989 sourceNot checked — no full text of the source

Lelukuau and Tshenukutish terranes contain widespread evidence of HP granulite- and subordinate eclogite-facies assemblages in rocks with protolith ages varying from ~1620 Ma to 1170 Ma.

“Lelukuau and Tshenukutish terranes contain widespread evidence of HP granulite- and subordinate eclogite-facies assemblages in rocks with protolith ages varying from c45 1620 Ma to 1170 Ma (Indares et al. 2000).”

• cites Indares et al. 2000 sourceNot checked — no full text of the source

The thrust belt in Gagnon terrane exhibits a Barrovian metamorphic field gradient, with greenschist-facies rocks near the Grenville Front giving way to kyanite-bearing medium-pressure, upper amphibolite facies assemblages throughout much of Gagnon terrane.

“The thrust belt exhibits a Barrovian metamorphic field gradient, with greenschist-facies rocks near the Grenville Front giving way to kyanite-bearing medium-pressure, upper amphibolite facies assemblages throughout much of Gagnon terrane.”

Parry Sound domain is a klippe resting on Algonquin terrane.

“Parry Sound domain, a complex structural assemblage comprising three distinctive packages separated by ductile shear zones, is a klippe resting on Algonquin terrane (Wodicka et al. 1996).”

• cites Wodicka et al. 1996 sourceNot checked — no full text of the source

Muskoka domain overlies the southern part of the HP belt.

“Muskoka domain, SL5 of Ketchum and Davidson (2000), overlies the southern part of the HP belt (Fig. 2).”

• cites Ketchum and Davidson 2000 sourceNot checked — no full text of the source

The Algonquin and Lac Dumoine terranes consist predominantly of upper amphibolite- and granulite-facies gneisses.

“The Algonquin and Lac Dumoine terranes consist predominantly of upper amphiboliteand granulite-facies gneisses (Indares and Martignole 1990; Davidson 1998).”

• cites Indares and Martignole 1990 sourceNot checked — no full text of the source
• cites Davidson 1998 sourceNot checked — no full text of the source

The current geometry of the Composite Arc belt reflects principally thrusting and extension at c. 1080-1050 Ma.

“However, the current geometry of the belt reflects principally thrusting and extension at c45 1080-1050 Ma (Timmermann et al. 1997; Carr et al. 2000).”

• cites Timmermann et al. 1997 sourceNot checked — no full text of the source
• cites Carr et al. 2000 sourceNot checked — no full text of the source

Lelukuau terrane is overlain by Tshenukutish terrane along a southeast-dipping normal-sense shear zone.

“It is overlain by Tshenukutish terrane along a southeast-dipping normal-sense shear zone (Hynes et al. 2000).”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

Gagnon terrane consists predominantly of reworked Archean gneiss and its Paleoproterozoic cover that are imbricated in a northwest-vergent, metamorphic foreland fold-thrust belt.

“Gagnon terrane consists predominantly of reworked Archean gneiss and its Paleoproterozoic cover that are imbricated in a northwestvergent, metamorphic foreland fold-thrust belt (Rivers 1983 a , 1983 b ; van Gool 1992; Rivers et al. 1993).”

• cites Rivers 1983aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Rivers 1983bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites van Gool 1992Not checked — no full text of the source

The estimated age of metamorphism of the Algonquin gabbro is 1060-1045 Ma, determined from metamorphic zircon overgrowths on baddeleyite.

“The estimated age of metamorphism of the Algonquin gabbro is 1060-1045 Ma (Davidson and van Breemen 1988; Heaman and LeCheminant 1993), determined from metamorphic zircon overgrowths on baddeleyite.”

• cites Davidson and van Breemen 1988 sourceNot checked — no full text of the source
• cites Heaman and LeCheminant 1993 sourceNot checked — no full text of the source

The overlying LP belt in the central Grenville Province consists of Lac Joseph, Hart Jaune, and Berthé terranes.

“The overlying LP belt in the central Grenville Province consists of Lac Joseph, Hart Jaune, and Berthé terranes.”

Evidence for HP metamorphism in the retrogressed eclogite-facies rocks is generally indirect, due to extensive granulite- and amphibolite-facies overprinting.

“Evidence for HP metamorphism in the retrogressed eclogite-facies rocks is generally indirect, due to extensive granulite- and amphibolite-facies overprinting.”

The Composite Arc and Frontenac belts were situated in the upper crust during the Ottawa orogeny.

“We infer from this distribution that the Composite Arc and Frontenac belts were situated in the upper crust during the Ottawa orogeny.”

Evidence for HP metamorphism in Molson Lake terrane is best preserved in the dry interiors of the gabbro dykes, which display a spectacular range of corona assemblages.

“Evidence for HP metamorphism is best preserved in the dry interiors of the gabbro dykes, which display a spectacular range of corona assemblages (Rivers and Mengel 1988; Indares 1993; Indares and Rivers 1995).”

• cites Rivers and Mengel 1988 sourceNot checked — no full text of the source
• cites Indares 1993 sourceNot checked — no full text of the source
• cites Indares and Rivers 1995 sourceNot checked — no full text of the source

Recent evidence supports the inference that the Composite Arc and Frontenac belts were at a very high crustal level during emplacement of some ~1070 Ma granitoids in the southeastern Composite Arc belt, including narrow contact aureoles, granophyric groundmass, and miarolitic cavities.

“This inference is supported by recent evidence for the very high crustal level of emplacement of some ~1070 Ma granitoids in the southeastern Composite Arc belt, including narrow contact aureoles, granophyric groundmass, and miarolitic cavities (Davidson 2001).”

• cites Davidson 2001Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

In the GFTZ in Ontario, evidence for two high-grade metamorphic events has been recorded at c45 1060 Ma and c45 980 Ma (Ottawa and Rigolet orogenies, respectively).

“In contrast, in the GFTZ in Ontario, evidence for two high-grade metamorphic events has been recorded at c45 1060 Ma and c45 980 Ma (Ottawa and Rigolet orogenies, respectively; Jamieson et al. 1995).”

• cites Jamieson et al. 1995 sourceNot checked — no full text of the source

Muskoka domain appears to lack relict eclogite-facies units.

“It also appears to lack relict eclogite-facies units, although the significance of local occurrences of garnet-clinopyroxene rocks (Davidson 1991) requires further investigation.”

• cites Davidson 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Farther east in Réservoir Dozois terrane, estimated P-T conditions of 900-1000 MPa and 750°C (undated) were also followed by quasi-isothermal decompression.

“Farther east in Réservoir Dozois terrane, estimated P-T conditions of 900-1000 MPa and 750°C (undated) were also followed by quasi-isothermal decompression (Indares and Martignole 1990).”

• cites Indares and Martignole 1990 sourceNot checked — no full text of the source

Lelukuau terrane, at the structural base of the Manicouagan Imbricate zone, consists of a stack of thrust slices (the Manicouagan thrust system) bounded by generally southeast-dipping shear zones.

“Lelukuau terrane, at the structural base of the Manicouagan Imbricate zone, consists of a stack of thrust slices (the Manicouagan thrust system) bounded by generally southeast-dipping shear zones (Indares et al. 2000).”

• cites Indares et al. 2000 sourceNot checked — no full text of the source

The controversy over the timing of HP metamorphism hinges on interpretation of relationships between the retrogressed eclogite and spatially associated coronitic Algonquin metagabbro.

“The controversy hinges on interpretation of relationships between the retrogressed eclogite and spatially associated coronitic Algonquin metagabbro.”

The observation that relict eclogite-facies rocks are restricted principally to shear zones provides qualitative support for the interpretation that the Algonquin gabbro underwent HP metamorphism but failed to react because of kinetic constraints.

“The observation, noted earlier in the text, that the relict eclogite-facies rocks are restricted principally to shear zones, provides qualitative support for the second interpretation.”

At depth, the Grenville Front is a listric structure that soles out in the crust-mantle boundary.

“At depth, it is a listric structure that soles out in the crust-mantle boundary (Hynes et al. 2000; White et al. 2000).”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source
• cites White et al. 2000 sourceNot checked — no full text of the source

The Grenville Front is the trace of a series of southeast-dipping thrust or reverse faults that place higher grade rocks of the Parautochthonous belt on lower grade equivalents in the foreland to the northwest.

“The Grenville Front , the northwestern boundary of the Grenville Province, is the trace of a series of southeast-dipping thrust or reverse faults that place higher grade rocks of the Parautochthonous belt on lower grade equivalents in the foreland to the northwest (Rivers et al. 1989).”

• cites Rivers et al. 1989 sourceNot checked — no full text of the source

In the central Grenville Province, the presence of Shabogamo gabbro in both the Parautochthonous belt (Gagnon terrane) and the overlying HP belt (Molson Lake terrane) suggests that these two terranes were contiguous prior to Grenvillian metamorphism.

“In detail, the presence in the central Grenville Province of Shabogamo gabbro in both the Parautochthonous belt (Gagnon terrane) and the overlying HP belt (Molson Lake terrane) suggests that these two terranes were contiguous prior to Grenvillian metamorphism”

Maximum estimated P-T conditions in Lelukuau and Tshenukutish terranes, where garnet-kyanite clinopyroxenite and subordinate true eclogite are widespread, are similar to those for Molson Lake terrane, in the range 1400 to 1900 MPa and 770 to 920°C.

“Maximum estimated P-T conditions in Lelukuau and Tshenukutish terranes, where garnet-kyanite clinopyroxenite and subordinate true eclogite are widespread, are similar to those for Molson Lake terrane, in the range 1400 to 1900 MPa and 770 to 920°C (Indares 1997; Cox and Indares 1999 a , 1999 b ; Indares et al. 2000).”

• cites Indares 1997 sourceNot checked — no full text of the source
• cites Cox and Indares 1999 a , 1999 bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Indares et al. 2000 sourceNot checked — no full text of the source

Berman (in Davidson 1991) calculated that the minimum conditions of eclogite formation in mafic rocks of this bulk composition were c45 1450 MPa at 700°C.

“Berman (in Davidson 1991) calculated that the minimum conditions of eclogite formation in mafic rocks of this bulk composition were c45 1450 MPa at 700°C”

• cites Berman (in Davidson 1991)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The restriction of preserved eclogite-facies assemblages to mafic plutonic rocks is probably a function of processes during the retrograde metamorphic evolution, when only the cores of structurally competent, relatively dry lithologies, such as metagabbro that had reacted to eclogite, would have withstood decompression reactions and the accompanying strain that elsewhere resulted in granoblastic,

“This restriction is probably a function of processes during the retrograde metamorphic evolution, when only the cores of structurally competent, relatively dry lithologies, such as metagabbro that had reacted to eclogite, would have withstood decompression reactions and the accompanying strain that elsewhere resulted in granoblastic granuliteor amphibolite-facies assemblages (e.g., Rubie 1990;”

• cites Rubie 1990 sourceNot checked — no full text of the source
• cites Boundy et al. 1992 sourceNot checked — no full text of the source

The presence of relatively pristine eclogite in the central Grenville Province is compatible with rapid unroofing synchronous with transport onto the Parautochthonous belt following formation.

“The presence of relatively pristine eclogite in the central Grenville Province is compatible with rapid unroofing synchronous with transport onto the Parautochthonous belt following formation.”

In the western Grenville Province, the HP rocks were imbricated with Muskoka domain.

“In contrast, in the western Grenville Province, where the HP metamorphism occurred earlier but is less well dated, the HP rocks were subsequently transported into the mid-crust, where they were imbricated with Muskoka domain and underwent penetrative granulite-facies recrystallization from c45 1080 to 1060 Ma (Ottawa orogeny).”

The hanging-wall terranes must have been in the upper crust at the time their footwalls were undergoing HP metamorphism.

“Common to all the hanging-wall terranes is the preservation of pre-Ottawan metamorphic ages, with the concomitant lack of widespread, penetrative Ottawan metamorphism, implying that they must have been in the upper crust at the time their footwalls were undergoing HP metamorphism.”

The metasedimentary gneiss in Lac Joseph terrane displays evidence for two generations of anatectic leucosomes, both of which are Labradorian in age.

“The metasedimentary gneiss displays evidence for two generations of anatectic leucosomes, both of which are Labradorian in age (Connelly et al. 1995).”

• cites Connelly et al. 1995 sourceNot checked — no full text of the source

In the western Grenville Province, the HP rocks were subsequently transported into the mid-crust.

“In contrast, in the western Grenville Province, where the HP metamorphism occurred earlier but is less well dated, the HP rocks were subsequently transported into the mid-crust, where they were imbricated with Muskoka domain and underwent penetrative granulite-facies recrystallization from c45 1080 to 1060 Ma (Ottawa orogeny).”

In the western Grenville Province, the presence of Sudbury diabase in the Parautochthonous belt but its absence in the overlying HP belt may imply a less intimate association between these belts.

“whereas in the western Grenville Province, the presence of Sudbury diabase in the Parautochthonous belt, but its absence in the overlying HP belt may imply a less intimate association.”

The Grenville Front has a ramp-flat geometry near the present erosion surface, as suggested by its surface trace comprising relatively straight segments and more gently dipping lobate segments.

“Its surface trace comprises relatively straight segments, characterized by moderately to steeply dipping, amphibolite-facies shear zones, and more gently dipping lobate segments where metamorphic, foreland fold-thrust belts are developed, the dichotomy suggesting that it has a ramp-flat geometry near the present erosion surface.”

Hart Jaune terrane consists predominantly of gneisses that preserve evidence for two granulite-facies metamorphic events at 1470 Ma and 989 Ma (Pinwarian and Rigolet orogenies, respectively).

“Hart Jaune terrane consists predominantly of gneisses that preserve evidence for two granulite-facies metamorphic events at 1470 Ma and 989 Ma (Pinwarian and Rigolet orogenies, respectively; Scott and Hynes 1994; Hynes and St-Jean 1997; Hynes et al. 2000).”

• cites Scott and Hynes 1994Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Hynes and St-Jean 1997Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

Estimated conditions of HP metamorphism range from 1400 MPa / 750°C in the north of Molson Lake terrane to 1800 MPa and 850°C farther south.

“Estimated conditions of HP metamorphism range from 1400 MPa / 750°C in the north of Molson Lake terrane to 1800 MPa and 850°C farther south (Indares 1993; Indares and Rivers 1995).”

• cites Indares 1993 sourceNot checked — no full text of the source
• cites Indares and Rivers 1995 sourceNot checked — no full text of the source

In both the central and western Grenville Province, the lithological evidence is compelling that the Parautochthonous, HP, and LP belts were all components of the Laurentian margin.

“Nonetheless, in both areas the lithological evidence is compelling that the Parautochtonous, HP, and LP belts were all components of the Laurentian margin.”

The HP belt shared a common Paleo- and Mesoproterozoic history with the Parautochthonous belt and the LP belt prior to the Grenvillian orogenic cycle.

“These observations imply that the HP belt shared a common Paleo- and Mesoproterozoic history with the Parautochthonous belt and the LP belt prior to the Grenvillian orogenic cycle.”

The characteristic preservation of relict igneous texture in the Algonquin metagabbro indicates that it is less pervasively recrystallized than the retrogressed eclogites.

“The characteristic preservation of relict igneous texture in this unit indicates that it is less pervasively recrystallized than the retrogressed eclogites.”

This observation is compatible with evidence from the western Grenville Province that the HP rocks subsequently underwent granulite-facies metamorphism during the Ottawa orogeny.

“This observation is compatible with evidence from the western Grenville Province that the HP rocks subsequently underwent granulite-facies metamorphism during the Ottawa orogeny.”

The only definitive report of HP assemblages preserved in a non-mafic lithology is that of Indares (1995), who described HP relics in pelitic rocks from part of Gagnon terrane in the immediate footwall of the HP belt.

“The only definitive report of HP assemblages preserved in a non-mafic lithology is that of Indares (1995), who described HP relics in pelitic rocks from part of Gagnon terrane in the immediate footwall of the HP belt.”

• cites Indares (1995)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The Parautochthonous, HP, and LP belts were (semi-)contiguous components of the southeastern margin of Laurentia during the Mesoproterozoic prior to the Grenvillian collision.

“We therefore infer, with Carr et al. (2000), that the Parautochthonous, HP, and LP belts were (semi-)contiguous components of the southeastern margin of Laurentia during the Mesoproterozoic prior to the Grenvillian collision.”

• cites Carr et al. (2000) sourceNot checked — no full text of the source

The P-T estimates for the Algonquin gabbro may represent conditions attained during granulite-facies reequilibration.

“but as discussed earlier in the text, these may represent conditions attained during granulite-facies reequilibration.”

The pervasive granulite-facies reequilibration of eclogite during the Ottawa orogeny in the western Grenville Province suggests a two-stage exhumation process involving a period of residence in the middle crust before emplacement on the Parautochthonous belt.

“In contrast, the pervasive granulite-facies reequilibration of eclogite during the Ottawa orogeny in the western Grenville Province suggests a two-stage exhumation process involving a period of residence in the middle crust before emplacement on the Parautochthonous belt (e.g., Indares and Dunning 1997).”

• cites Indares and Dunning 1997 sourceNot checked — no full text of the source

Although tectonically dismembered, the Algonquin metagabbro bodies are commonly clustered, implying that they are fragments of larger intrusions.

“Although tectonically dismembered, the bodies are commonly clustered, implying that they are fragments of larger intrusions (Ketchum and Davidson 2000).”

• cites Ketchum and Davidson 2000 sourceNot checked — no full text of the source

Understacking of the future HP belt led to eclogite-facies metamorphism near the base of the doubly thickened crust.

“Understacking of the future HP belt led to eclogite-facies metamorphism near the base of the doubly thickened crust.”

In cross-section C, normal displacement on a structure in a similar location to the Mid-Parautochthon detachment may have been considerable, since it is visible on Lithoprobe seismic sections and is inferred to result in crustal thinning and displacement of the crust-mantle boundary.

“In cross-section C, in contrast, normal displacement on a structure in a similar location may have been considerable, since it is visible on Lithoprobe seismic sections and is inferred to result in crustal thinning and displacement of the crust-mantle boundary (Martignole et al. 2000).”

• cites Martignole et al. 2000 sourceNot checked — no full text of the source

The footwall beneath the HP belt in the western Grenville Province was hotter and weaker than in the central Grenville Province.

“implying that it was hotter and weaker than in the central Grenville Province.”

Emplacement of the HP belt on the Paleoproterozoic margin resulted in thin-skinned imbrication of the underlying parautochthonous supracrustal rocks.

“Emplacement of the HP belt on the Paleoproterozoic margin resulted in thin-skinned imbrication of the underlying parautochthonous supracrustal rocks.”

During the Rigolet orogeny, the adjacent foreland and upper part of the footwall were incorporated into the orogenic wedge as a foreland fold-thrust belt.

“In the final stage of tectonic development during the Rigolet orogeny (Fig. 11D), the adjacent foreland and upper part of the footwall were incorporated into the orogenic wedge as a foreland fold-thrust belt (van Gool and Cawood 1994).”

• cites van Gool and Cawood 1994Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Early unroofing of the HP belt was not a result of regional extension.

“Thus early unroofing of the HP belt was not a result of regional extension.”

Displacement on the Mid-Parautochthon and Allochthon Boundary detachment systems in cross-section A could not have contributed directly to unroofing of the HP rocks.

“so displacement on them could not have contributed directly to unroofing of the HP rocks.”

Coeval normal faulting along the Upper Allochthon detachment above the HP belt, leading to unroofing by tectonic extrusion, resulted in widespread preservation of the HP mineralogy and texture.

“Coeval normal faulting along the Upper Allochthon detachment above the HP belt, leading to unroofing by tectonic extrusion, resulted in widespread preservation of the HP mineralogy and texture (Hynes et al. 2000).”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

The Frontenac terrane was situated in the upper crust during the Ottawa orogeny.

“the inference that Frontenac terrane was situated in the upper crust during the Ottawa orogeny.”

In cross-section D, displacement on the Allochthon Boundary detachment was limited, as indicated by the HP belt occurring on both sides of the detachment.

“In cross-section D, the HP belt occurs on both sides of the Allochthon Boundary detachment suggesting that displacement was limited there.”

Displacement on the Allochthon Boundary detachment in cross-section E could have contributed significantly to unroofing the HP terranes.

“and thus could have contributed significantly to unroofing the HP terranes.”

The Allochthon Boundary detachment in cross-section E was the site of major displacement.

“suggests that it was the site of major displacement”

The first effect of the collisional orogeny was imbrication of the future LP belt onto the HP belt along the Upper Allochthon thrust.

“The first effect of the collisional orogeny was imbrication of the future LP belt onto the HP belt along the Upper Allochthon thrust (Fig. 11B).”

Displacement on the Allochthon Boundary detachment in cross-sections D and E could have contributed to unroofing, as the detachments lie within or above the HP belt there.

“On the other hand, displacement on the Allochthon Boundary detachment in cross-sections D and E could have contributed to unroofing, as the detachments lie within or above the HP belt there.”

The existence of one or more normal-sense shear zones in eastern Molson Lake terrane immediately below and subparallel to the Upper Allochthon detachment is inferred on metamorphic grounds.

“The existence of one or more normal-sense shear zones in eastern Molson Lake terrane immediately below and subparallel to the Upper Allochthon detachment (Fig. 3), where metamorphic grade ranges from midto lower amphibolite facies (Connelly 1991), is inferred on metamorphic grounds.”

• cites Connelly 1991Not checked — no full text of the source

The Allochthon Boundary detachment shear zones are tentatively linked as a single detachment system because of their close spatial relationship to the HP belt.

“However, they are tentatively linked here because of their close spatial relationship to the HP belt.”

The inference that several of the detachments sole out at or near the crust-mantle boundary implies that the latter remained ductile until late Grenvillian time.

“The inference that several of the detachments sole out at or near the crust-mantle boundary implies that the latter remained ductile until late Grenvillian time.”

The HP belt must have been transported into the mid-upper crust prior to extensional faulting.

“implies that the HP belt must have been transported into the mid-upper crust prior to extensional faulting.”

A similar architecture and evolution to cross-section D are inferred in cross-section E.

“and a similar architecture and evolution are inferred in cross-section E.”

Following attainment of peak metamorphic conditions, probably at about 1080-1060 Ma, the HP belt was uplifted along the Allochthon Boundary thrust with its ramp-flat geometry.

“Following attainment of peak metamorphic conditions, probably at about 1080-1060 Ma, the HP belt was uplifted along the Allochthon Boundary thrust with its ramp-flat geometry (Fig. 11C).”

The imbrication of the future LP belt onto the HP belt may be recorded by rare thrust-sense kinematic indicators preserved in Lac Émérillon shear zone.

“This event is largely inferred, but may be recorded by rare thrust-sense kinematic indicators preserved in Lac Émérillon shear zone (Connelly 1991).”

• cites Connelly 1991Not checked — no full text of the source

The ramp-flat shape of the Allochthon Boundary detachment in cross-section E is inferred to be a late feature associated with cross-folding.

“The ramp-flat shape of the Allochthon Boundary detachment in cross-section E is inferred to be a late feature associated with cross-folding (Connelly et al. 1995).”

• cites Connelly et al. 1995 sourceNot checked — no full text of the source

The HP belt must have been tectonically transported to mid- to upper crustal levels before the onset of the Rigolet orogeny.

“implying that it must have been tectonically transported to mid- to upper crustal levels before the onset of the Rigolet orogeny.”

• AssumptionRests on an assumption: A tectonic load on the HP belt gave rise to the HP metamorphism.

Three crustal-scale detachment systems are identified that may provide links between several of the cross-sections: the Mid-Parautochthon, the Allochthon Boundary, and the Upper Allochthon detachment systems.

“three crustal-scale systems are identified that may provide links between several of the cross-sections. These are referred to here as the Mid-Parautochthon , the Allochthon Boundary and the Upper Allochthon detachment systems .”

Total displacement of the underlying Archean rocks was probably minor.

“although total displacement of the latter was probably minor (van Gool 1992).”

• cites van Gool 1992Not checked — no full text of the source

The units making up the tectonic load were not penetratively deformed or metamorphosed during the Ottawa orogeny.

“Taken overall, these units were not penetratively deformed or metamorphosed during the Ottawa orogeny”

• AssumptionRests on an assumption: A tectonic load on the HP belt gave rise to the HP metamorphism.

The terranes with pre-Ottawan metamorphic ages that are currently situated in the hanging wall of the HP belt made up part of the tectonic load on the HP belt during the Ottawa orogeny.

“We infer that the terranes with pre-Ottawan metamorphic ages that are currently situated in the hanging wall of the HP belt made up part of this load”

• AssumptionRests on an assumption: A tectonic load on the HP belt gave rise to the HP metamorphism.

Inferred offsets of the crust-mantle boundary in cross-section C suggest that latest displacements on the detachments took place after significant cooling of the crust-mantle boundary region in late Rigolet time.

“Inferred offsets of the crust-mantle boundary in cross-section C suggest that latest displacements on the detachments took place after significant cooling of the crust-mantle boundary region in late Rigolet time.”

The crust under the Parautochthonous belt in the central Grenville Province is about 5 km thicker than average.

“implying that crust is about 5 km thicker than average”

In cross-section C, preservation of offsets on the Moho implies that displacement on the Allochthon Boundary detachment probably continued until late Rigolet time.

“whereas in cross-section C, the preservation of offsets on the Moho implies that displacement probably continued until late Rigolet time there.”

In the western Grenville Province, the eclogite-facies assemblages developed in lower crustal rocks originally situated near the former leading edge of the Laurentian margin as a result of accretion of the Composite Arc and Frontenac-Adirondack belts.

“In the west, the eclogite-facies assemblages appear to have developed in lower crustal rocks originally situated near the former leading edge of the Laurentian margin as a result of accretion of the Composite Arc and Frontenac-Adirondack belts (Fig. 12).”

The tectonic models for the central and western Grenville Province are overall similar.

“Despite the undetermined difference in timing of HP metamorphism and the single-stage versus two-stage decompression, the overall similarity between the tectonic models for the central and western Grenville Province is striking.”

In the western Grenville Province, HP metamorphism is inferred from field relations to have resulted from tectonic burial of the Laurentian margin, as a result of accretion of the combined Composite Arc and Frontenac-Adirondack belts.

“In the western Grenville Province, HP metamorphism is inferred from field relations to have resulted from tectonic burial of the Laurentian margin, as a result of accretion of the combined Composite Arc and Frontenac-Adirondack belts.”

The Shawanaga shear zone is situated beneath the HP belt.

“Shawanaga shear zone is situated beneath the HP belt, so displacement on it would have brought the HP rocks in its hanging wall into contact with hot lower crust in its footwall (Wodicka et al. 2000) but would not have contributed directly to unroofing of the HP belt.”

• cites Wodicka et al. 2000 sourceNot checked — no full text of the source

In both the central and western Grenville Province, there was a predominant progression of thrusting towards the foreland (understacking) during orogenic evolution.

“In both areas there is a predominant progression of thrusting towards the foreland (i.e., understacking) during orogenic evolution, and both imply transport of the HP rocks to upper crustal levels by late Ottawan time.”

The negative Bouguer gravity anomaly under the Parautochthonous belt in the central and eastern Grenville Province developed during Rigolet time as the orogen advanced into its foreland.

“The negative Bouguer gravity anomaly under the Parautochthonous belt in the central and eastern Grenville Province, one of the most conspicuous gravity anomalies in the Canadian Shield, is inferred to have developed during Rigolet time as the orogen advanced into its foreland.”

The HP belt was incorporated into the orogen by basal accretion to the orogenic wedge.

“This resulted in incorporation of the HP belt into the orogen, a process that has been termed basal accretion to the orogenic wedge (e.g., Dahlen and Barr 1989; Royden 1993).”

• cites Dahlen and Barr 1989 sourceNot checked — no full text of the source
• cites Royden 1993 sourceNot checked — no full text of the source

Exhumation of the HP belt in the central Grenville Province occurred by tectonic extrusion.

“Exhumation of the HP belt in the central Grenville Province by tectonic extrusion.”

The architecture in Fig. 9A represents a modification of an original ramp-flat geometry as observed in cross-sections Figs. 9B-9E.

“We thus infer that the architecture in Fig. 9A represents a modification of an original ramp-flat geometry as observed in cross-sections Figs. 9B-9E.”

Extension above the HP belt in the central Grenville Province led to tectonic extrusion of the HP rocks.

“leading to tectonic extrusion of the HP rocks (Hynes et al. 2000)”

• cites Hynes et al. 2000 sourceNot checked — no full text of the source

The location of the site of the inferred early fault separating the HP footwall from its hanging wall in the central Grenville Province was determined by a preexisting weakness in the Laurentian crust.

“In this setting, the impetus for crustal thickening and eclogite-facies formation is inferred to have been continental collision, with the location of the site of the inferred early fault separating the HP footwall from its hanging wall being determined by a preexisting weakness in the Laurentian crust.”

Displacement on the Shawanaga shear zone would not have contributed directly to unroofing of the HP belt.

“Shawanaga shear zone is situated beneath the HP belt, so displacement on it would have brought the HP rocks in its hanging wall into contact with hot lower crust in its footwall (Wodicka et al. 2000) but would not have contributed directly to unroofing of the HP belt.”

The High Pressure (HP) belt is a first-order tectonic element of the Grenville Province.

“We have defined the High Pressure (HP) belt as a first-order tectonic element of the Grenville Province through examination of HP rocks from two areas some 800 km apart in the western and central parts of the province.”

The Michael and Shabogamo gabbros are chemically similar.

“the Michael and Shabogamo gabbros are chemically similar (Gower et al. 1990)”

• cites Gower et al. 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Corona assemblages in the Mesoproterozoic Michael gabbro in Groswater Bay terrane are petrographically very similar to those in the Shabogamo gabbro.

“corona assemblages in the Mesoproterozoic Michael gabbro in Groswater Bay terrane, reported by Gower (1986), are petrographically very similar to those in the Shabogamo gabbro”

• cites Gower (1986) sourceNot checked — no full text of the source

The orogen grew progressively into its foreland by understacking.

“The figure also illustrates the progressive growth of the orogen into its foreland by understacking.”

The available data suggest that tectonic burial to eclogite-facies conditions in one part of the orogen was approximately coeval with partial unroofing, mid-crustal imbrication and granulite-facies heating elsewhere.

“The available data thus suggest that tectonic burial to eclogite-facies conditions in one part of the orogen was approximately coeval with partial unroofing, mid-crustal imbrication and granulite-facies heating elsewhere.”

The HP rocks were passively transported on deeper thrust systems after late Ottawan time.

“(D) The passive transport of the HP rocks on deeper thrust systems after late Ottawan time.”

Having attained their maximum depths of burial, the HP rocks in the central Grenville Province began a single-stage process of tectonic unroofing.

“Having attained their maximum depths of burial, the HP rocks in the central Grenville Province began a single-stage process of tectonic unroofing”

The Archean craton comprised a mechanically competent buttress or ramp that focused extrusion of the HP rocks above it in the central Grenville Province.

“The restriction of Archean rocks to the footwall of the HP belt in the central Grenville Province is significant and is compatible with the inference that the Archean craton comprised a mechanically competent buttress or ramp that focused extrusion of the HP rocks above it (e.g., Hynes and Eaton 1999; Hynes et al. 2000).”

• cites Hynes and Eaton 1999 sourceNot checked — no full text of the source
• cites Hynes et al. 2000 sourceNot checked — no full text of the source

The protoliths of the HP rocks were deeply buried units of the Paleo- to Mesoproterozoic Laurentian margin.

“their protoliths were deeply buried units of the Paleoto Mesoproterozoic Laurentian margin.”

Unroofing of the HP belt involved one- or two-stage northwest-directed tectonic transport of HP rocks along the Allochthon Boundary thrust and onto the footwall ramp in a compressional regime.

“One- or two-stage northwest-directed tectonic transport of HP rocks along the Allochthon Boundary thrust and onto the footwall ramp in a compressional regime”

Gravity data suggest that crustal thickening during the Rigolet orogeny may have been considerable.

“Gravity data suggest that crustal thickening during the Rigolet orogeny may have been considerable.”

The complete compensation of any former gravity anomaly in the western Grenville Province is compatible with the lower crust and Moho being hotter and more ductile there.

“We suggest that the depressed Moho in the central Grenville Province is consistent with a relatively cool, rigid lower crust beneath the Parautochthonous belt there, whereas, in contrast, the complete compensation of any former gravity anomaly in the western Grenville Province is compatible with the notion that the lower crust and Moho were hotter and more ductile there.”

In the western Grenville Province, any former Bouguer gravity anomaly has been completely compensated by rise of the Moho.

“The presence of a residual negative Bouguer anomaly indicates that the Moho remains depressed there as a result of excess crustal thickness, whereas in the western Grenville Province any former anomaly has been completely compensated by rise of the Moho.”

The sequence of tectonic processes implies an overall, in-sequence forelandward progression of thrusting by understacking.

“This sequence implies an overall, in-sequence forelandward progression of thrusting by understacking”

The depressed Moho in the central Grenville Province is consistent with a relatively cool, rigid lower crust beneath the Parautochthonous belt there.

“We suggest that the depressed Moho in the central Grenville Province is consistent with a relatively cool, rigid lower crust beneath the Parautochthonous belt there, whereas, in contrast, the complete compensation of any former gravity anomaly in the western Grenville Province is compatible with the notion that the lower crust and Moho were hotter and more ductile there.”

Uplift may have been partly suppressed by focused thrust loading as a result of the orogenic bend in the western Grenville Province, thereby prolonging the time available for thermal relaxation.

“As noted earlier in the text, uplift may have been partly suppressed by focused thrust loading as a result of the orogenic bend in this area, thereby prolonging the time available for thermal relaxation.”

Early unroofing in both the western and central Grenville Province probably took place in a thrust regime that led to transport of the HP rocks onto a footwall ramp.

“Early unroofing in both areas probably took place in a thrust regime that led to transport of the HP rocks onto a footwall ramp.”

The development of the HP belt in both the western and central Grenville Province can be accommodated in a similar tectonic setting.

“Overall, from an orogenic perspective, it is clear that the development of the HP belt in both the western and central Grenville Province can be accommodated in a similar tectonic setting.”

In-sequence forelandward progression of thrusting by understacking may be an essential component of the exhumation process.

“which may be an essential component of the exhumation process”

The Ottawan granulite-facies metamorphism in the mid-crust in the western Grenville Province may have taken place as a result of transport of the eclogite-facies rocks from double crustal depths coeval with thrust loading associated with the collision.

“the Ottawan granulite-facies metamorphism in the mid-crust in the western Grenville Province may have taken place as a result of transport of the eclogite-facies rocks from double crustal depths coeval with thrust loading associated with the collision.”

Rigolet out-of-sequence thrusting and metamorphism occurred in Berthé terrane in the central Grenville Province.

“Rigolet out-of-sequence thrusting and metamorphism in Berthé terrane in the central Grenville Province (Ludden and Hynes 2000)”

• cites Ludden and Hynes 2000 sourceNot checked — no full text of the source

The timing of the accretionary event in the western Grenville Province is dated by the age of the eclogite-facies metamorphism, which remains contentious.

“The timing of this accretionary event is, therefore, dated by the age of the eclogite-facies metamorphism, which as noted, remains contentious.”

This part of the Laurentian margin in the central Grenville Province had also been doubled in thickness by this time.

“implying that this part of the Laurentian margin had also been doubled in thickness by this time (Fig. 12B).”

In the central Grenville Province, HP metamorphism took place inboard from the former Laurentian margin.

“and took place inboard from the former Laurentian margin.”

Final unroofing occurred as a result of passive transport in the upper crust during the Rigolet orogeny in both the western and central Grenville Province.

“Final unroofing occurred as a result of passive transport in the upper crust during the Rigolet orogeny in both areas.”

Abundant field evidence for ductile flow in the western Grenville Province shows that the process had a profound effect on the geometry of rock units.

“The abundant field evidence for ductile flow in this area shows that the process had a profound effect on the geometry of rock units, leading us to suspect that any original architecture of the ramp up which the HP rocks were transported is no longer preserved.”

Late Ottawan metamorphism of the Mazinaw domain in the Composite Arc belt occurred at c. 1020 Ma.

“late Ottawan metamorphism of Mazinaw domain in the Composite Arc belt ( c45 1020 Ma, Corfu and Easton 1997)”

• cites Corfu and Easton 1997 sourceNot checked — no full text of the source

Extensional displacement on the Shawanaga shear zone in the western Grenville Province occurred at c. 1020 Ma (latest Ottawan).

“As noted, Ketchum et al. (1998) have dated extensional displacement on Shawanaga shear zone in the western Grenville Province at c45 1020 Ma (i.e., latest Ottawan).”

• cites Ketchum et al. (1998) sourceNot checked — no full text of the source

The unroofing of HP rocks in the central Grenville Province was probably along steep P-T gradients.

“probably along steep P-T gradients (Indares et al. 2000)”

• cites Indares et al. 2000 sourceNot checked — no full text of the source

At the beginning of the Rigolet orogeny, the HP belt in both the western and central Grenville Province was in the hanging wall of the thrust wedge and was transported passively towards the northwest.

“At this time, the HP belt in both the western and central Grenville Province was in the hanging wall of the thrust wedge and was transported passively towards the northwest.”

The ECSOOT profile exhibits a doubly vergent character with southeast-dipping reflectors in the north and northwest-dipping reflectors farther south that converge in the lower crust.

“the ECSOOT profile exhibits a doubly vergent character with southeast-dipping reflectors in the north and northwest-dipping reflectors farther south that converge in the lower crust (Gower et al. 1997)”

• cites Gower et al. 1997 sourceNot checked — no full text of the source

Both the central and western Grenville Province models imply transport of the HP rocks to upper crustal levels by late Ottawan time.

“In both areas there is a predominant progression of thrusting towards the foreland (i.e., understacking) during orogenic evolution, and both imply transport of the HP rocks to upper crustal levels by late Ottawan time.”

Formation of the eclogite-facies rocks in the western Grenville Province occurred as a result of burial of the Laurentian margin under the Composite Arc and Frontenac-Adirondack belts.

“Fig. 12A shows that formation of the eclogite-facies rocks in the western Grenville Province occurred as a result of burial of the Laurentian margin under the Composite Arc and Frontenac-Adirondack belts.”

The tectonically overlying Hawke River terrane appears to have escaped Grenvillian metamorphism.

“the tectonically overlying Hawke River terrane appears to have escaped Grenvillian metamorphism (Gower 1996)”

• cites Gower 1996 sourceNot checked — no full text of the source