Laurel Hill Plantation's Loess Laurel Hill Plantation's Loess Deposits T wenty thousand years ago the world was in the grips of an ice age, with about a quarter of the earth's face mantled with huge sheets of ice. These ice sheets are referred to as continental glaciers, and in many places they were one to two miles thick, or even thicker. Twenty thousand years ago, the closest these glaciers came to Laurel Hill Plantation at Natchez area was about 500 miles to the north, just north of the Ohio River. When such outrageous quantities of water rampage across the landscape, it doesn't carve out graceful meanders, or even scour for itself a comfortably deep channel, like a regular river. It forms a broad floodway composed of an interconnecting maze of channels.
None are very deep.
Between the channels lie islands composed of sand and gravel dumped there by fast-moving currents. Some of the islands are tiny but some are large, and sometimes they are occupied by mud flats. Such networks of interconnecting channels are referred to technically as braided streams . Braided streams can be seen today below melting glaciers in the Far North and among the higher mountains, as well as upon alluvial fans at the base of mountains issuing large amounts of meltwater when winter's snows melt during the spring. Today if you fly over the San Gabriel Mountains north of Cucamonga, California, during the spring, you can see nice ones.