Geology Study Guide

Only available on StudyMode
  • Download(s) : 72
  • Published : February 20, 2013
Open Document
Text Preview
GEOLOGY 101 Exam 1 Study Guide
Geology| * The science that examines Earth, its form and composition, and the changes that it has undergone and is undergoing * The processes are slow, but none the less dynamic * Physical geology: examines Earth materials and seeks to understand the many processes that operate on our planet * Historical geology: seeks an understanding of the origin of Earth and its development through time| Scientific Method| * It is a rigorous process whereby new ideas about how some part of the natural world works are put to the test * The result of testing must be reproducible * It is believed that the universe is orderly and that by observing it objectively, we can learn how it works * How does testing take place? * Starts with a question * Collect evidence/data that answers the question| Hypothesis| * A tentative conclusion/explanation about natural processes being questioned * It can be revised/changed as needed * Scientists are actually trying to prove the conclusion wrong| Scientific Theory| * A conclusion/explanation that is supported by experimental or factual evidence but has not been conclusively proved * Theories explain the data in a concise manner * Example: E = mc2 theory of relativity| Natural Law| * Never ever false|

Alfred Wegener| * “Father of Plate Tectonics,” German meteorologist * Introduced his hypothesis in “Origins of Continents and Oceans” in 1915 * Suggested that a super continent called Pangaea (all lands) existed during most of the Paleozoic * 200 Ma (Mz) Pangaea began breaking up into smaller pieces (continents) and moved to their present location| Evidence that supports continental drift| * Fit of continents looked like pieces of a puzzle * Fossils * Mesosaurus: snaggle toothed reptile; found exclusively in South America and Africa; lived in fresh water * Glossopteris: seed fern associated with polar climates; found in Africa, Australia, India and South America; from late Paleozoic seeds * Fossils were separated by: rafting, isthmian links, island stepping stones, continental drift * Paleoclimate Evidence: polar climate in late Pz – tropical conditions, major coal fields * Geologic structures: mountain belts and stratigraphy match across oceans * Major criticism: no mechanism for movement of continents| Harry Hess| * In the early 1960s, Harry Hess of Princeton University incorporated these newly discovered facts into a hypothesis that was named seafloor spreading. He proposed that oceanic ridges are located above zones of upwelling in the mantle. As rising material reaches the base of the lithosphere it spreads laterally, carrying the seafloor in a conveyor-belt fashion away from the ridge crest. Tensional forces fracture the crust and proved pathways for magma to intrude and generate new slivers of oceanic crust. As the seafloor moves away from the ridge axis, newly formed crust replaces it. | Seafloor spreading| * Midoceanic ridges (MORs) * A global oceanic mountain belt * Noted parallel to continental margins * High heat flow along ridges * MORs form in crust above convection cells in mantle * Crust breaks and magma leaks into the fractures and forms new sea floor * What is happening at the other end of the plate? Seafloor is being pushed into the mantle, forming trenches * Deep sea trenches: super deep “valleys” in the ocean floor, seismic activity very high| Geomagnetic reversals| * The earth’s magnetic field periodically changes direction * Magnetic north because magnetic south and vice versa * Seafloor striping: seafloor can be magnetized by Earth’s magnetic field – it records geomagnetic flips| Age of seafloor| * Progressively older away from mid-oceanic ridges| Rocks| * The crust of the earth is composed of rocks * Rock: an aggregate of one or more minerals| Minerals| * Naturally occurring solids *...
tracking img