The Pangean fit of South to North America leaves no space for the crust of present southern Mexico and Central America, thus these areas formed after the breakup of Pangean or arrived from elsewhere. Present information indicates that these terranes have discordant geologic histories suggesting that their early histories are unrelated. The Chortis block is the only terrane on the Caribbean plate with a known Paleozoic and possible Proterozoic history, and is considered an important key to solving the puzzle of Caribbean tectonics. This project will conduct geochronologic analysis of the Chortis block to place structural events in a firm temporal framework. These data, combined with available geologic, structural and tectonics constraints, will allow testing of hypotheses relating Chortis crust to specific sources in North America, and to test hypotheses relating Tertiary tectonic transport of the Chortis block to the development of the Caribbean plate.
