BIO211H5 Lecture Notes - Lecture 3: Sedimentology, Maple Syrup, Exponential Growth
Document Summary
Plate tectonics is the movement of rigid tectonic plates that compose the outer crust of the earth. The crust is composed of continental and oceanic crust. Oceanic crust is heavier, denser, and younger than continental crust. As we discussed last class, oceanic crust subducts under continental crust. With plate tectonics comes plate rotation and plate movement. As these plates are rotating around, they are creating new connections. The continent that we re on has not always been the north american continent. There is a cycle of continental construction and deconstruction. Approximately 200 million years ago, a large continent called pangaea deconstructed into two smaller continents (gondwana and laurasia). About 100 million years ago gondwana fragmented into africa, south america, india, australia, and antarctica. India and australia are on one large plate called the indo-australian plate. About 100 million years ago, india and australia start to fracture off and begin to rotate.
