Compilation of radiometric age dates from the Great Arc of the Caribbean: Evidence for an in situ or Pacific-derived Caribbean plate?

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2018-10-18

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I have used GIS to compile ~2000 radiometric dates from Cretaceous to Paleogene, island arc related rocks in the circum-Caribbean that formed a single, continuous “Great Arc of the Caribbean". The goal is to test two models for Caribbean plate evolution: an in situ arc that was static between the North and South American plates - or a mobile, Pacific-derived arc. One challenge for the study is deformation and uplift: for example, the Hispaniola arc segment has experienced Neogene deformation and uplift and therefore exposes older levels of the Great Arc. Thus, I emphasize the youngest, arc-related dates in each arc segment as a way to track the location of the Caribbean plate. Ages in Cuba show no particular directional pattern.  Two arc segments show good west to east younging progressions with a lateral change from Cretaceous to Paleogene arc ages and include: 1) a 300-km-long segment from Puerto Rico through the Virgin Islands; and 2) a 500-km-long segment from northern Colombia to the Lesser Antilles arc. The age progressions yield roughly the same rate of west-to-east plate motion inferred from subsidence and from plate models and therefore supports the Pacific origin of the arc.

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