Earth History GEOL 2110

1. Earth History GEOL 2110 Midterm 1 Preparation/Review

2. Style of Questions • Matching term w/ definition, person w/ notable accomplishment • Short definition of concepts/processes • Name some of multiple characteristics REVIEW PowerPoints!! Understand Figures in Text.

3. Cuvier and BrongnairtBiostratigrapy of the Paris Basin (1811-1822) Geologic Correlation between Paris and London (1722)

4. Toward a Unified Theory of the EarthThe Neptunists A.G. Werner (1787) - Developed a chronostratigraphy of the Earth’s crust that was based on progressive deposition of rocks from a gradually subsiding ocean. The theory was nearly universally accepted in the late 1700’s. Defined five crustal units: Primitive Series – crystalline rocks considered to be the first precipitates from the ocean before the emergence of land. Transition Series - more indurated sedimentary sequences that were the first orderly deposits from the ocean. Secondary Series - the remaining, obviously stratified fossiliferous rocks and certain associated "trap" rocks. These were thought to represent the emergence of mountains from beneath the ocean and were formed from the resulting products of erosion deposited on their flanks. Alluvial Series - poorly consolidated sands, gravels and clays formed by the withdrawal of the oceans from the continents. Volcanic Series - younger lavas flows demonstrably associated with volcanic vents. Werner believed that these rocks reflected the local effects of burning coal beds. Abraham Gottlob Werner 1749-1817

5. Early Ideas about Evolution • Defined “biology” as a study of the plant and animal world • Ideas about evolution published in 1809, where he argued that the fundamental course of nature is change and this change was controlled by environment • Did not ascribe to Buffon’s fixed species concept, but rather believed that organism represent a continuum of change. • Did not believe in extinction, but rather the “loss” of an organism was due to it’s changing into or replacement by another form. Jean Baptiste de Monet – Chevalier de LAMARCK (1744–1829)

6. Evidence of EvolutionHomologous Elements Diverse organisms share similar organs and features For example, the bones of appendages in a variety of vertebrates Green –humerus Red – radius Blue – ulna Tan – wrist and phalanges

7. Charactersitics of a Scientific Theory • Based on facts, but not a statement of certainty or truth • Testable – holds up to repeated testing • Predictive – forward and backward in time • Explains many related natural phenomenon • Deemed by a majority of scientists to have a high probability of being correct

8. Genetic Theory The Mechanism behind Evolution • Mendel discovered that when cross-breeding purple and white flower colors, a blended color did not result, but rather colors remained distinct with the purple color being more common • Morever, the first generation would produce only purple colors and in the second generation 25% of the flowers would be white, 75% purple • Devised the notion of dominant and recessive hereditary traits

9. Categories of Stratigraphic Units Units based on content or physical limits Lithostratigraphic Lithodemic Magnetopolarity Biostratigraphic Pedostratigraphic Allostratigraphic A lithodemicunitis a defined body of predominantly intrusive, highly deformed, and/or highly metamorphosed rock, distinguished and delimited on the basis of rock characteristics. In contrast to lithostratigraphic units, a lithodemic unit generally does not conform to the Law of Superposition.

10. Subdivisions of Geologic Units Fundamental Units From NASC, 2005

11. Walther’s Law The vertical progression of facies will be the same as the corresponding lateral facies changes

12. Decay of Radioactive Isotopes Beta decay of Rb87 to Sr87

13. The Revised Solar Nebula Theory In the thermal gradient of the solar nebula, different elemental compounds would have condensed at different temperatures. This explains the compositional progression of the planets from the heavy element-rich inner planets and light element-rich outer ones

14. Layers of the Earth • --Mohorovicic • Discontinuity OCEANIC CONTINENTAL CRUST CRUST SiO2 47% 56% Al2O3 16% 18% FeO 13% 9% MgO 10% 3% CaO 10% 4% Na2O 2% 5.5% K2O 0.7% 2.5% TiO2 1.1% 1.3% P2O5 0.2% 0.7% MANTLE SiO2 – 45% MgO – 37% FeO – 8% Al2O3 – 4% CaO – 3% others – 3% CORE Fe – 86% S – 10% Ni – 4% Compositional Layers Structural Layers = chondritic meteorites

15. Alfred Wegener Father of the Theory of Continental Drift 1915 – The Origin of Continents and Oceans (3rd edition, 1922) Meteorologist by training Introduced the hypothesis of Continental Drift Postulated the existence of the supercontinent he named Pangea Evidence: Fit of the continents Fossil record Similar geologic structures Similar paleoclimates Alfred Wegener1880-1930

16. Types of Plate Boundaries