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Stratigraphy. The study of sedimentary rock layers. Big Idea 2. Earth is 4.6 billion years old. 2.1 Earth’s rocks provide a record of its history. HUTTON’S DISCOVERY. Giants of Geology. The beginnings of the science…and the big ideas…. Nicola Steno -- 1638 - 1686.
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Stratigraphy The study of sedimentary rock layers
Big Idea 2. Earth is 4.6 billion years old. • 2.1 Earth’s rocks provide a record of its history. • HUTTON’S DISCOVERY
Giants of Geology The beginnings of the science…and the big ideas…
Nicola Steno --1638 - 1686 Steno’s Law of Superposition = oldest rocks on bottom Steno’s Law of Original Horizontality = rock layers form from soft sediments horizontally...tilting comes later
Steno & fossils Fossils ARE bones, not just rocks that look like bones
Robert Hooke 1635-1703 Contemporary of Newton, Boyle (gas laws) Fossils are not “sports of nature” but remnants of past life
William Smith 1769-1839 First geologic map of England Law of Faunal Succession-- different fossils are found in different layers...in order! = biostratigraphy
James Hutton 1726 - 1797 “Father of geology” plutonic intrusions and angular unconformities = evidence of “deep time”
James Hutton 1726 - 1797 Siccar Point, Scotland
Charles Lyell 1797 - 1875 Uniformitarianism-- “the present is the key to the past” = gradualism vs. catastrophism...
Sedimentary Rocks and Stratigraphy: The three most abundant kinds of sediment: Quartz Sand, Shale, Limestone
Simple Ideal Model for the Evolution of Sedimentary Rocks: HighENERGYLow “Rocks reflect the conditions at which they formed.” --Fichter & Poche
First Premise: • Sedimentary rock compositions depends on • tectonic regime • depositional environment
Second Premise: • Depositional environments are predictable: • From sourceland to basin:
Conclusion: • Changes in: • Sediment composition • Sediment textures • Sedimentary structures • Rock sequences • happen predictably from sourceland to basin