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Guidelines for Understanding Quaternary Stratigraphy

Learn about the complexities and challenges of Quaternary stratigraphy, including rapid climate fluctuations, dating limitations, and various stratigraphic approaches like lithostratigraphy and biostratigraphy.

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Guidelines for Understanding Quaternary Stratigraphy

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  1. A primer on Quaternary Stratigraphy and Terrestrial Sedimentology

  2. Concerns for Q stratigraphy • Rapid fluctuations of climate, thus rapid and complex stratigraphy • Time-transgressive units are the rule • Dating and correlation limitations: correlation of records is the key • Complexities of terrestrial stratigraphy

  3. Stratigraphy and correlation • At one site: temporal dimension: stratigraphy • At one time: spatial dimension: correlation • If the Q record were complete and well dated everywhere, a time-stratigraphic framework of environmental change could be developed • But that framework is hampered by: • few long, continuous records, • fragmented terrestrial records, • dating challenges

  4. Stratigraphic approaches • Lithostratigraphy • Chronostratigraphy • Biostratigraphy • Chemostratigraphy (incl. Oxygen isotope stratigrapy) • Magnetostratigraphy • Climatostratigraphy (geologic-climatic units) • Morphostratigraphy (allostratigraphic units)

  5. Lithostratigraphy • A very important first step in any stratigraphic sequence • Forms the basis for interpreting stratigraphy in terms of processes and history • Descriptive vs. genetic terminology • e.g., diamicton vs. till

  6. Time-transgressive sequences Lowe and Walker, 1997

  7. Lithostratigraphy Bedsmembersformations Lithofacieslithofacies associations Lowe and Walker, 1997

  8. Lowe and Walker, 1997

  9. LithofaciesLithofacies associations

  10. Biostratigraphy Lowe and Walker, 1997

  11. Marine oxygen isotope stratigraphy SC Porter Oxygen isotope stratigraphy has proven one of the best means of subdividing the Q, and has been formalized in recent years, see http://www.encyclopedia.com/doc/1O112-Quaternaryoxygnstpchrnlgy.html

  12. Magnetostratigraphy

  13. Morphostratigraphy Lowe and Walker, 1997

  14. ca. 60 ka? (between 54 and 115 ka) ∆T~4ºC @ SL (Heusser, 1972) : Lyman Rapids advance (27 X 48 km)

  15. Hoh Oxbow 1 advance 33-30 cal ka ∆T~4ºC @ SL (Heusser, 1972) : (27 X 48 km)

  16. Twin Creeks 1 advance 22-21 ka (LGM equivalent; 27 km retreat from maximum) ∆T~5ºC @ SL (Heusser, 1972) : (27 X 48 km)

  17. Climatostratigraphy Lowe and Walker, 1997

  18. Chamberlin’s glacial stages Wisconsin glaciation Sangamon interglaciation Illinoian glaciation Yarmouth interglaciation Kansan (Independence) glaciation Nebraskan (Albertan) glaciation USGS

  19. Correlation issues: time/space-transgressive climatic changes Lowe and Walker, 1997

  20. Chronostratigraphy Lowe and Walker, 1997

  21. Lowe and Walker, 1997

  22. Examples of multi-proxy Quaternary records

  23. Lowe and Walker, 1997

  24. Lowe and Walker, 1997

  25. Lowe and Walker, 1997

  26. Lowe and Walker, 1997

  27. Lowe and Walker, 1997

  28. Rocky Mountain glacial stratigraphy Lundeen, 2001

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