Geology GEOL-G 130 Lecture Notes - Lecture 4: West Antarctica, Massachusetts Route 3, Divergent Boundary
Document Summary
Formation of west antarctic basin: is a basin below sea level, rocks are basalt, formed 80-100 million years ago, affects ice sheet stability, why is west antarctica below sea level. New zealand pulls away from antarctica 65 mya (cretaceous: stretching makes the valley, basalt forms 65-20 ma, stretching stops, rocks are really dense, sinking slow. Supercontinent gondwana: 180-300mya, affected evolution of life, antarctica not at pole, no ice sheet, forests and dinosaurs, 200-300 mya (permian-jurassic, no w. a. basin yet, now transantarctic mountains, then a large river valley. Granite formation along transantarctic mountains: 550 mya granites extend 1000 miles. Super continent rodinia: 1. 4 billion years ago, evidence: matching rocks east antarctica and sw u. s. Major changes and events: supercontinent rodinia, subduction. Granite formation along tam: supercontinent gondwana. Environments for life: west antarctic rift. Uplift of tam: opening of drake pssage. Erosion flattens mountinas over a few hudnered million years: produces lots of sediments.
