Earth Sciences 1086F/G Lecture Notes - Lecture 7: Calcite, Paleozoic, Geologic Time Scale
Document Summary
2. 0 earth"s earliest history: accretion: growth by accumulation of smaller bodies, dust and gas (first 20 million years, the first large object would attract others by gravity and as it grew, this became faster. 2. 1 the iron catastrophe: earth"s composition = iron (30%), oxygen, magnesium, silicon, and sulphur (total. 3. 0 a differentiated earth: when earth was molten, there was a general zonation of elements (heavy- light) which is called differentiation. The zones of differentiation are called inner core, outer core, mantle and crust, with oceans and atmospheres sitting on top. 3 therefore slower to respond to outside forces the rotation of one metal inside the other is the basis for the dynamo"s construction: sometimes due to turbulence in the liquid core, the dynamo gets confused (ex. 5. 0 plate tectonics: lithosphere divided into plates. Vertical was accepted; horizontal was different: alfred wegener was interested in the parallelism of the coastlines on either side of the atlantic ocean.