The Astronomical Theory of Climatic Change: Barbados Data

Abstract

The island of Barbados, West Indies, was an area of tectonic emergence during the Pleistocene. As Barbados was uplifted, reef tracts formed around the island. The interaction of gradual tectonic uplift of the island and glacio-eustatic sea level fluctuations has resulted in the formation of a complex, terraced "coral cap." Each individual terrace represents an elevated reef tract and is therefore constructional rather than erosional in origin. Subsequent to formation, the reef terraces have been abraded by waves and subjected to minor faulting; in particular, wave abrasion has extensively modified the morphology of some of the terraces. Radiometric dating of successive reef terraces suggests periods of high sea level and associated individual reef tract developments about 82,000, 105,000, and 125,000 years ago. The next higher group of terraces was formed between 170,000 and 230,000 years ago; the rest of the terraces were formed more than 250,000 years ago. Marked interruptions in the development of well-defined reef terraces from Recent to 80,000 years ago and from 130,000 to 170,000 years ago apparently record prolonged periods of relatively low sea level. The ages of the reef terraces compare closely with times of maximum summer solar radiation in the Northern hemisphere and therefore lend strong support to the astronomical theory of climatic change.