Other than the stars, the planets have the longest damn memory. Ours included.
I wanted to have a larger view of the history of the land where I garden, which seems so impossibly old. So:
We are at latitude 42.38, longitude -72.65, in West Hatfield, Massachusetts, on the western side of Hampshire County. To the east of us lies the Connecticut River, and beside it, flat farmlands stretch to the east and Hatfield proper itself.
On the western side, we live and garden on a craggy, fern-strewn, boulder-ridden, rocky and weird wild zone. It feels less refined than Hatfield, which was founded in 1660, because it is both metaphorically and literally true. Hatfield is smooth and flat; nice farmland.
The Pleistocene Era, which is meant when we say ‘the Ice Age’, was last major glacial period on Earth. For those of us whose knowledge of geology is limited to what we established reading The Far Side, that is about 2.5 million to eleven thousand years ago. Nothing much was happening, so a rough temporal estimate of 2.5 million years made sense.
During that time, the Laurentide ice sheet covered most of North America.
Over those thousands of years, the Laurentide sprawled forward and nosed along a mix of rock and regolith called a moraine (regolith is rock that doesn’t quite qualify as rock–sand, clay, gravel). The rock and regolith pushed in front of a glacier as it moves forward is called a terminal moraine, as if it were shoved by a giant snowplow.
In the late Pleistocene era, eighteen thousand years ago, Lake Hitchcock began forming in New England when the Laurentide ice sheet began melting and retreating northward, leaving the remnants of the terminal moraine behind.
As the ice receded, more frozen detritus melted into the terminal moraine, swept forward by the melting water. The dam and then the banks of Lake Hitchcock were formed, stretching two hundred miles from central Connecticut into Vermont.
The lake remained five thousand years or so, until the end of the Pleistocene era, when erosion–all of that sediment and melting water–slowly, finally, compromised the structure of the lake. The thin trickle that had eased into Long Island Sound smoothed out and became the Connecticut River.
As a result of that lake and its slurry of fish goo and rotted plant debris, the Connecticut River Valley has the richest agricultural soil in New England.
This is research pulled together during a five-hour stint at the Forbes Library in Northampton, MA. The citations at the end of the Wikipedia entry for Lake Hitchcock were a helpful place to start if anyone wants to dig deeper. Search terms I used included ‘Connecticut River valley geology’ and if by some chance someone with actual expertise wanders by, would love input on this brief history of ten thousand to 2.5 million years ago.