Glaciers compacted soil into hardpan that slows groundwater to a trickle
Evidence
But first Guswa had to explain why, in his scientific opinion, W. R. Grace could not have contaminated the wells. As a graduate student, Guswa had specialized in the study of glaciers, and he brought that specialty to bear on the Woburn case. The terrain of east Woburn, he explained to the jury, had been shaped twelve thousand years ago, at the end of the last Ice Age, when an immense glacier more than a mile thick had covered the New England landscape. In its advance and retreat, the glacier had deposited a layer of soil fifty feet deep on the bedrock ridge where the Grace plant was now located. Soil of that type, compressed under the glacier’s enormous weight, was known to geologists as ground moraine, or hardpan. It was densely compacted and groundwater seeped through it very slowly, like water trickling through a pipe stuffed with sediment. — , Harr Jonathan - A Civil Action, 2148
Categorization
- DEFINE: Ground moraine/hardpan defined as soil compressed under glacial weight, densely compacted so water seeps slowly through it.
- SHARE: The ‘ground moraine or hardpan’ definition plus the glacier-a-mile-thick image is a niche geology tidbit for the friend who likes glacial landscapes.
- XREF: connects to: Soil formation takes centuries, making its loss nearly irreparable — Vinson Brown, Reading the Woods: Seeing More in…, 230; Lichens colonize bare glacial rock over centuries where no soil can accumulate — Robin Wall Kimmerer, Braiding Sweetgrass: Indigenous Wisdom,…, 984
Broader Connections
- Soil formation takes centuries, making its loss nearly irreparable
#qualifies(0.85) — Vinson Brown, Reading the Woods, 230 - Lichens colonize bare glacial rock over centuries where no soil can accumulate
#complicates(0.80) — Robin Wall Kimmerer, Braiding Sweetgrass, 984