GEOL 1003 : Chap 8 10 Review
Document Summary
Plate tectonics- proposes that discrete segments of earth"s crust and upper mantle move in relation to other segments. Pre-plate tectonics view- cartographers noticed something about continents- fit together. Glossopteris- fern fossil leaves found across continents, suggesting joined. Gondwanaland- hypothesized landmass that was connected subaerially and then sunk. Problems with gondwanaland- hard to explain distribution of modern mammals on madagascar, india, Madagascar mammals closely resemble those in india while being hugely separated. Alfred wegener- suggested continents together in geologic past. Noted fossils of mesosaurus, rock assemblages, glaciers, gondwana + laurasia = pangaea. Mesosaurus- small reptile, fossils found in brazil and africa. Dark shales with fossil insects and crustaceans (boundary between carboniferous and permian). Geologic similarities- brazil and s. africa have nearly identical geologic sequences, with similar fossils and sedimentary layers. Gondwana + laurasia- pangaea formed in late paelozoic, but before that, gondwanaland (south) and. Why cdt rejected?- could not figure out mechanism, timing was off- wegener said drift occurred in.
