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Ancient environments Central Kansas - 80 Ma
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Setting the Stage: Major Erosional/Depositional ‘Provinces’
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Understanding the distant past by reconstructing: Ancient environments Ancient climates Ancient life Ancient ecosystems “The present is the key to the past.” “The past is the key to the present.”
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Ancient Environments Paleoenvironment A past environment (i.e., meandering stream, delta, ocean basin) that existed in a given area. Determined through the study of: modern depositional systems rocks & enclosing structures biological remains (fossils)
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Paleoenvironment Present-Day environments ? Yazoo River Aerial viewCross section
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Paleoenvironment Present-Day environments ? Mississippi Delta Aerial viewCross section
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Paleoenvironment Present-Day environments ? Outer Banks Aerial viewCross section
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Clues Within the Sediment I Minerals? Grain size? Grain sphericity? Grain sorting? Matrix?
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Clues Within the Sediment II Planar Bedding Cross Bedding Imbrication Graded Bedding Cut and Fill Ripple Bedding
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Which way did the current flow?
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Graded Bedding in a modern stream deposit Ancient Stream Deposit
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Paleoenvironment The Geological record Paleozoic deltaic deposits in Tennessee
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Paleoenvironment The Geological record Paleozoic meandering stream deposits in Pennsylvania
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Paleoenvironment The Geological record Eocene barrier island deposits in South Carolina
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Paleoenvironment The Biological Record Wright whale 40 Ma whale skeleton, Egypt
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Ancient Climates Paleoclimate Determined through the study of: modern climate rocks & associated structures/fossils chemistry Temperature, humidity, rainfall, etc. in a given area during a particular ancient time interval.
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Climate Present-Day Climates? Alpine/Polar (glaciers) Desert (dune fields)
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Paleoclimate The Geological Record Desert (aeolean sandstone) Alpine/Polar (morraines)
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Paleoclimate The Biological Record woolly mammoth trees & other plants
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Paleoclimate Chemical records foraminifera Ice cores Scallops & other mollusks
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Temperature Fluctuation Based on O-18 analyses Chemical records – oxygen 18
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Sea Level Fluctuation Based on O-18 analyses
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North America during last glacial maximum ~ 21 Ka
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During the: Ord = Ordovician P/T = Permo-Triassic Cretac = Cretaceous PETM = Paleocene-Eocene Thermal Maximum LGM – Last Glacial Maximum LIA - Little Ice Age Paleogeographic map & Paleotemperature distributions
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Ancient Life Paleontology Life that existed during a particular time interval in the distant past. Understanding gained through the: examination of preserved remains (fossils) comparison to living organisms
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Paleontology Types of Fossils Body Fossils Molds & Casts Carbon Films
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Paleontology Present-Day Equivalents? Tiger skull Scallop dragonfly
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Ancient Ecologies Paleoecology Interactions among living organisms living within a particular ancient environment. Understanding gained through the: study of modern ecologies examination of fossils
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Ecology Great Barrier Reef, Australia
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Reconstructing Paleoecology Niobrara Formation (85 Ma), Kansas Study Rock Exposures
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Reconstructing Paleoecology Niobrara Sea (85 Ma), North America Determine Depositional Environment
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Reconstructing Paleoecology Collect and Study Fossils Plesiosaur Ammonite Mosasaur
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Niobrara Sea (85 Ma), Kansas
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Paleobiology “Fish-within-a-fish” – Niobrara Formation (85 Ma), Kansas Study of the mode of life of organisms (i.e., how big an animal grew, how it moved, what it ate)
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Paleobiology Pierre Sea (72 Ma), South Dakota
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Paleobiology Pierre Sea (72 Ma), South Dakota
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Paleobiology/Paleoecology Baby mammoth – permafrost (40 Ka), Siberia, Russian Federation
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