From Bureau of Economic Geology, The
University of Texas at Austin (www.beg.utexas.edu).
Bureau Seminar, September 7, 2007
Pangea breakup and the early evolution of the Central Atlantic Ocean, assembly of Mexico, and opening of the Gulf of Mexico
Bird Geophysical, University of Houston
Closing ocean basins, by rotating tectonic plates about Euler poles to corresponding geomagnetic isochrons, is an objective method for analyzing reconstructed continental margins. Reconstructions of the North American, South American and African plates for Chrons M40 (165.1 Ma), M25 (154.1 Ma), and M0 (124.6 Ma), including the accretion of the continental blocks that form Mexico as well as the opening of the Gulf of Mexico over these time frames, reveal critical aspects for understanding the tectonic evolution of the region. Early sea floor spreading in the Central Atlantic included two ridge jumps (ca 170 Ma and ca 160 Ma) that are thought to be related to tectonic plate reorganization, following the breakup of Pangea and initial sea floor spreading in the Central Atlantic (ca 180 Ma), including the opening of the Gulf of Mexico.