1 / 31

Quaternary Geomorphology

Quaternary Geomorphology. A Workshop for P.G . Candidates December 18, 2010 Dr. Don Thieme . Geochronology, Glacial Intervals, Isotopic Dating, etc... Glacial Landforms and Sedimentary Deposits Soil Classification and Paleosols Sea Level and Coastal Geomorphology.

reina
Télécharger la présentation

Quaternary Geomorphology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Quaternary Geomorphology A Workshop for P.G. Candidates December 18, 2010 Dr. Don Thieme

  2. Geochronology, Glacial Intervals, Isotopic Dating, etc... • Glacial Landforms and Sedimentary Deposits • Soil Classification and Paleosols • Sea Level and Coastal Geomorphology

  3. Glacial Landforms and Sedimentary Deposits

  4. Glaciers • glaciers form where snowfall is high and temperatures low • high altitudes (alpine glaciers) • high latitudes ( ice sheets) • accumulation– addition of snow to a glacier • snowfall • rain • ablation – the loss of snow and ice from a glacier • melting • sublimation • calving

  5. Alpine Glacier Profile

  6. Inputs (zone of accumulation) vs. Outputs (zone of ablation) Three Possible Situations: Inputs > outputs - advancing glacier Inputs = outputs – stationary glacier Inputs < outputs – retreating glacier end moraine till plain end moraine   

  7. Ogives • “waves” or “bands” of ice • annual features useful for calculating velocity of glacial advance and retreat • also indicate glacier base and margins Ogives icefield near Juno, AK

  8. Esker in former glacial lake, Waterford, Maine

  9. Esker near Dahlen, North Dakota

  10. Eskers - subglacial origin Esker fill near Plattsburgh, New York showing “openwork” (clast-supported) gravel overlying coarse sand beds

  11. "morphosequence" of glacial and proglacial landforms • all deposits laid down as the ice stood at a mappable location on the Earth's surface. • proglacial deposits are supplied by the "dirt machine" that occurs where live ice rides up over stagnant ice.

  12. Proglacial rivers or lakes may begin directly in front of the stagnant ice: (A = fluvial ice-contact; C = lacustrine ice-contact). Proglacial lakes may be fed by meltwater rivers (D = Fluvial lacustrine ice-contact)

  13. Rivers may be fed by water from a proglacial lake through a spillway (F = Lacustrine fluvial ice-contact)

  14. glaciers dam pre-existing rivers • glaciers depress the land surface, forming new lake basins • glaciers produce moderate to large volumes of water during spring thaw • continental glaciers produced particularly large volumes of water when they melted back during the late Pleistocene

  15. Nellie Juan Glacier and terminal moraine, Prince William Sound, Alaska. (http://pubs.usgs.gov/of/2004/1216/m/m.html)

  16. Ohio and Missouri Rivers follow ice margins Glacial Lakes occur north of both rivers No Glacial Lakes south of these rivers

  17. Climbing ripples from an ice-contact delta in Rhode Island Varves in a Swedish glacial lake

  18. The "channeled scablands" in Washington state were formed by outburst floods from proglacial Lake Missoula

  19. Shelbyville Carbondale

  20. Devensian glaciation (OIS- 2, 4) followed by the Flandrian transgression (OIS-1) in England, Wales, and Scotland

More Related