PHYSICAL ENVIRONMENT
The Town of Middleborough is inland in Plymouth County, bounded to the south by Wareham, to the west by Lakeville, to the east by Carver and Plympton and to the north by Bridgewater. Drainage in the northern part of the town is via the river and in the south by various brooks. Assawompsett and Quitticus Pond border the southwestern side of the town.
The topographic situation of the the project area is on two terraces overlooking one of the ton’s primary rivers on a mostly flat surface (50-75 ft contours). The project area occupies a polygonal-shaped area approximately 20 acres in size. An unnamed brook on the west side and a wetland on the east, both of which drain south into the river, bound the project area on these sides.
Bedrock in the project area is of Narragansett Rift Basin variety, which is primarily of Pennsylvanian age (Carboniferous Period 394-290 million year BP). The entirety of Plymouth County is part of the Avalonian Tectonic Terrane which was bedrock platform, essentially an island or micro-continent, that evolved almost completely independently from the rest of North America within the proto-Atlantic Ocean. This is similar to the present day situation with Japan which is an island that will someday collide with China. The Avalonian Terrane eventually collided with what is now North America and helped to form the Appalachian Mountain range. The main stone types consist of meta-sedimentary rocks that are highly folded and fractured, dark colored siltstone, shale, graywacke, argillite and coarse-grained conglomerate. Encountered in the subsoil of north end lots 1 and 2 were large rocks and smaller boulders of argillite.
The last ice age to affect North America was the Wisconsin glaciation (1.64 million years to 10,000 years BP). The glaciers that had advanced as far as present day Martha’s Vineyard and Nantucket, had begun retreating by 25,000 years BP. The retreat had reached Boston by 14, 000 years BP and New England was ice-free by 13,000 years BP. Soils in the project area are the result of the glacial retreat and the creation of large rivers, temporary lakes and braided streams caused by the melting of the ice. Two types of soils were present within the project area: Montauk and Windsor. Montauk very stony coarse sandy loam on 3 to 8 percent slopes (formerly named Essex soils) were present in the western third of the project area in the north end lots 1 and 2 and in lots 3, 4, the Lot 5 house envelope, and the retention detention basin. Montauk soils, formed in glacial till or upland and, are well-drained and deep. They occur on upland plains, hills and ridges and their main use is for woodland, hay, pasture, silage. corn, oats, and potatoes. Original forest vegetation would have included red, white, black and scarlet oak, red maple, sugar maple, beech, gray birch, white pine and hemlock. The main limitations for development consist of the presence of large surface and subsurface stones and boulders as well as a slow permeability due to a dense substratum. Montauk soils also are found beyond the eastern edge of the project area.
Windsor loamy sands on 8 to 15 and 15 to 35 percent slopes make up the largest part of the soils within the project area. Windsor soils on 8 to 15 percent slopes occur in the middle of the project area between lots 1 and 2 and the proposed , and from the Lot 5 septic envelope to the proposed lot 7 septic envelope. Windsor soils on 15 to 35 percent slopes occur to the east of lots 7, 8 and 9. They are very deep and excessively drained, having formed on glacial outwash or eolian deposits on plains, deltas and on the tops of glacial stream terraces like those associated with the river. Windsor soils are well-suited for corn, hay or pasture, vegetable or nursery stock. Forested areas contain white, black, and northern red oak, eastern white pine, pitch pine, gray birch, poplar, red maple, and sugar maple.
Located to the immediate west of the project area is an area of Swansea series muck. Mucks form in depressions and have low permeability and are poorly-drained. Located to the north and east of the Windsor soils and outside of the project area is an extensive area of developed peat associated with a swamp.
Significant wetlands form a broad crescent around the project and generally around Middleborough Center. Ice retreat at the end of the Wisconsin glaciation and the creation of a landscape crisscrossed by braided streams and temporary lakes that created them.
The river began its life as a glacial river cutting through newly deposited sediments at this same time. The project area is part of a high peninsula surrounded on three sides by river or significant wetland. Wetlands around the project area effectively isolate it as a high and dry rise among the marshes. This would have made the area very attractive to Native people, as it forms a contact zone between many resources associated with wetland/ swamp, riverine, and woodland zones. Native people could have exploited upland, riverine and swamp/ meadow species of flora and fauna within a two kilometer catchment area around the project area. The river itself would have provided them with an easy means of transport all the way to Narragansett Bay and inland to Assawompsett Pond, as well as providing anadromous fish during the spring fish runs. Lithic resources were probably procured from glacial deposits exposed along the river banks, within the river itself and within the subsoil. Local lithic raw materials recovered from the subsoil during the course of testing and excavation included argillite, quartz, quartzite and a limited selection of rhyolite.
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