GEOL 1001 Chapter : Chapter 2 Notes
Document Summary
Chapter 2: plate tectonics, grand unifying theory of geology, 20 distinct plates move and build regional geologic features, wegener: continents were once joined together to form a single huge supercontinent, Identical fossils found on widely separated landmasses: glossopteris- a subpolar plant with heavy seeds, mesosaurus- a freshwater reptile. Lystrosaurus- land-dwelling reptile: cynognathus- land-dwelling mammal, didn"t swim across the ocean, matching geologic units, distinctive rock assemblages and mountain belts match across the. Why: he couldn"t explain how or why continents moved. Depends upon : absolute position of the two poles, geographic north, magnetic north. Longitude: between the two poles declination can be 180 degrees, curved field lines cause a magnetic needle to tilt, depends upon . Inclination- tilt of a compass needle from the horizontal: normal or reverse polarity. Iron minerals in rock preserve information about the magnetic field at the time the rocks formed: declination and inclination preserved in rocks often vary from present latitude/longitude.
