A primer on Quaternary Stratigraphy and Terrestrial Sedimentology

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

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

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

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

Time-transgressive sequences Lowe and Walker, 1997

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

Lowe and Walker, 1997

LithofaciesLithofacies associations

Biostratigraphy Lowe and Walker, 1997

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

Magnetostratigraphy

Morphostratigraphy Lowe and Walker, 1997

(50 x 60 km)

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

Hoh Oxbow 1 advance 33-30 cal ka ∆T~4ºC @ SL (Heusser, 1972) : I also need to make the point that this one advanced and retreated within 3 ka--very tight dating and rapid growth and shirnkage for a big glacier. (27 X 48 km)

Twin Creeks 1 advance 22-21 ka (LGM equivalent; 27 km retreat from maximum) ∆T~5ºC @ SL (Heusser, 1972) : The poor, poor LGM. Note that the delta T is greater, but the ice extent way less (27 X 48 km)

Climatostratigraphy Lowe and Walker, 1997

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

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

Chronostratigraphy Lowe and Walker, 1997

Lowe and Walker, 1997

Examples of multi-proxy Quaternary records

Lowe and Walker, 1997

Lowe and Walker, 1997

Lowe and Walker, 1997

Lowe and Walker, 1997

Lowe and Walker, 1997

Rocky Mountain glacial stratigraphy Lundeen, 2001