ES 331/767 Lab IV

ES 331/767 Exercise IV
GREAT PLAINS GLACIAL
RECONSTRUCTIONS
James S. Aber

Introduction

The late Wisconsin ice sheet stopped well to the north of Kansas. The Des Moines lobe reached central Iowa around 14,000 years BP, and the James lobe may have crossed the Missouri River valley a short distance into northeastern Nebraska. Nonetheless, the environment of Kansas during the late Wisconsin glaciation was dramatically different from today. During the height of Wisconsin glaciation, some 14,000 to 20,000 years ago, the vegetation of Kansas included the following components (Fredlund and Jaumann 1987).

Continuous conifer forest of white spruce (Picea glauca) in the northeastern corner, like the boreal forest of central Manitoba today.
Mixed conifer/deciduous forest with spruce, pine, aspen, oak, willow, birch, elm, etc. intermingled with prairie openings of grass (Poaceae), ragweed (Ambrosia), and sagebrush (Artemisia) in the central area. The Flint Hills was a mixed pine/grassland environment, similar to the Pine Ridge today in northwestern Nebraska.
Conifer parkland with white and blue spruce (P. pungens), limber pine, and aspen along with prairie openings over the western High Plains, similar to the Black Hills today in South Dakota.

Exercise

See the large map of the northern and central Great Plains region of the United States (ice_labs.pdf, page 15). The map shows general geography--major rivers, states, and selected cities. The map will be the basis for illustrating glacial and environmental conditions that existed at two times during the Quaternary: (1) Independence glaciation, about 600,000 to 700,000 years ago during oxygen-isotope stage 16, and (2) late Wisconsin glaciation, about 14,000 to 18,000 years ago during oxygen-isotope stage 2. You should develop various symbols and use different colors to indicate the following features.

Ice sheet: position of ice limits, ice lobes and streams, ice-flow directions, ice thickness, etc.
Drainage: preglacial rivers, blocked drainage, ice-marginal rivers, proglacial lakes, catastrophic floods, etc.
Periglacial zone: permafrost, wind action: sand dunes, loess, etc.
Biology: tundra, forest and grassland, tree species, faunal provinces, etc.
Climatic zones: temperature (cold, warm), moisture (wet, dry), wind, etc.

Consult various lecture notes and figures (especially chapters 11, 16, 17) and other sites for information. You should prepare two maps, one for Independence and one for Late Wisconsin features, to avoid too much clutter on a single map. Provide brief written descriptions or explanations of glacial and environmental features depicted on your maps.

See pre-Wisconsin mapping project.

Note: This exercise is double credit--10 points for each map. You may submit paper copy or scan your maps and send image files (jpg, gif); ppt or pdf files are also acceptable. However, do not embed images in text files (rtf, doc).

Reference

Fredlund, G.G. and Jaumann, P.J. 1987. Late Quaternary palynological and paleobotanical records from the central Great Plains. Kansas Geological Survey, Guidebook Series 5, p. 167-178.