Rocks and Water
Redding lies in a physiographic province known as New England Upland. The bedrock underlying the hills and valleys there is largely metamorphic, consisting of schists, gneisses, and marble (a metamorphosed limestone). Many of these rocks are believed to be of Precambrian age-more than 600 million years old. Some were formed from pre-existing rock by the intense heat and pressure associated with the collision of continents and the formation of mountain ranges. From a molten state, igneous rocks were later injected into these formations. The intruders are called granite and pegmatite. The pegmatites, containing large crystals of quartz, feldspar and mica, are of particular interest because they may also embrace concentrations of rare minerals.
The Redding area experienced glaciation in recent geologic time (for "recent," how about 1.5 million years ago?), and the last glacier is believed to have retreated only ten to fifteen thousand years ago. The ice sheets left their mark. On the northwest slopes of many hills, bedrock has been polished smooth. The surface of some of these slopes shows numerous scratches, called glacial striations, which trace the direction the ice moved over the rocks. The southeastern sides of the hills are often rougher because, in passing, the ice plucked off pieces of rock and carried them away. The ice, in compensation, deposited large-often massive-boulders called "erratics" which you will come upon in the woods-souvenirs from another place and time.
When the melting glacier retreated, rocky fragments (called till) remained on the hillsides, while the finer particles washed into the valleys to form deep deposits (called stratified drift). Saturated with water, these deposits are the most productive aquifers in town. The thin till soils, on the other hand, do not transmit water very easily causing it either to run off or to collect in the shallow depressions of upland wetlands.
Redding is drained by four major watercourses: the Aspetuck River on the east; the Little River; the Saugatuck River; and the Norwalk River on the west. All but the ten percent of the Town that is tributary to the Norwalk River lies within a public water-supply area. This watershed is very sensitive to environmental pollution. The rock, soil and water of Redding combine to make a beautiful but fragile environment. It is one that deserves our respect and protection. ❧
The writer, Stanley Schleifer, is a former wetlands officer for the Conservation Commission.