GEOS 230T(S) The Ice Age Unmasked (Same as Environmental Studies 230T)

As recently as 18,000 years ago, thick glacial ice covered Williamstown and most of our hemisphere north of about 405, sea-level was some 120 m lower, crustal loading by the ice depressed some areas and lifted others, and climatic zones and vegetation shifted south. During the glaciation, ice and glacial meltwater sculpted the earth's surface, transporting and depositing a wide variety of sediments. As climate warmed, sea level rose quickly as water trapped beneath and next to ice masses escaped in a series of gigantic floods down the Columbia, Mississippi, Mackenzie, and other major drainages, catastrophically altering the landscape and possibly reversing climatic warming. The ice left behind sequences of landforms and deposits whose interpretation allows reconstruction of glacial environments and is of central importance in environmental issues such as groundwater supplies and proper waste disposal. Certain basic topics are controversial: how to interpret glacial sediments and landforms, how and why ice retreated, whether ice or water sculpted glacial landforms, and how ice sheets actually flow. In this tutorial we will read both classical literature that arose from the observation of glacial deposits and contemporary views shaped by glaciological principles, observations of modern glaciers, and the perception that catastrophic events are geomorphically significant. We will augment discussions of the literature by making observations of local glacial deposits and using reports of field observations to focus our reading. This course will follow the tutorial format. After an initial group meeting, students will meet in pairs for one hour each week with the instructor. Each student will orally present a written paper every other week for criticism during the tutorial session. Evaluation will be based on the five papers and on each student's effectiveness as a critic. Prerequisite: one upper-level Geosciences course or permission of the instructor.

Hour:  DETHIER