GEOL 1001 Chapter : Chapter One - Four
Document Summary
The earth produces a magnetic field that shields the planets from a solar wind. The dominant gas in the atmosphere is carbon dioxide. The density of the atmosphere decreases with increasing elevation. The mantel is composed of solid rock, where the core is composed of gold. According to wegener"s hypothesis of continental drift, all continents were once attached and formed a single landmass that he called pangaea. Continents on the east side could fit snugly against those on the west cost. When wegener compared rock samples now exposed on different continents bordering the atlantic ocean. Fossils of identical land-dwelling species occur on continents that are . Wegner could not explain how or why the continents move. The dipoles of tiny magnetite grains in basalt align with the earths field as the basalt cools and stay that way once basalt cools. Continents drift with respect to relatively fixed magnetic poles.
