GEOL 1001 Chapter : Geology Ch 2 Review Questions
Document Summary
Wegener suggested that a vast supercontinent, pangaea, existed until the end of mesozoic era. Pangaea then broke apart, and the land masses drifted away from each other to form continents we see today: evidence. When polar-wander paths are obtained from many different localities, it"s found that each continent has a different apparent polar-wander path. Crest of mid ocean ridges: roughly symmetric- depth variation on one side = depth variation on other side, roughly, deep-ocean trenches, along perimeters of pacific ocean, elongate troughs. Floor reaches depth of 8-12 km: seamount chains, isolated submarine mountains which were once volcanoes but no longer erupt, describe the hypothesis of sea-floor spreading. Hess suggested that molten rock rose upward beneath mid- ocean ridges and that this material solidified to form oceanic crust. The new sea floor then moved away from the ridge, a process we now call sea-floor spreading.
