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Research about Massachusetts

Source-linked reports with geographic coverage including Massachusetts.

At least 631 records · Page 35Linked to original sources
USGS1976

Beacon Hill end moraine, Boston: new explanation of an important urban feature

The usefulness of geology to engineers is in direct proportion to how well it helps us predict the subsurface; these predictions, in turn, depend on our knowledge of the geomorphic processes that molded the terrain. The uncertainties of interpretation are particularly great in glaciated terrain because our understanding of both glacial processes and history is so incomplete, a fact well illustrated in Beacon Hill. Recent construction activities in the eastern part of the hill, until now classified as a drumlin, have shown that it is better interpreted as an end moraine formed by a Wisconsonian glacial readvance. Instead of the firm till that was anticipated as foundation material, excavations exposed a complex of sand, gravel, and clay, with only minor zones of till. The structure of these deposits strongly suggests that originally they were plates of the glacial bed that froze to the glacier and were transported englacially. Thrust faulting and other deformations are glacial structures formed within the ice in the glacier's terminal zone. In spite of the complex englacial history, these deposits lost little of their original appearance and intergranular relationships. Upon deglaciation, the frozen moraine thawed, and slumping formed complex secondary structures on the ridge's lower flanks.

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USGS1976

Fresh ground water found deep beneath Nantucket Island, Masachusetts

In a deep water-resources and stratigraphic test well near the center of Nantucket Island, about 30 miles (48 kilometres) off the New England coast, freshwater has been found at greater depths than predicted by the Ghyben-Herzberg principle. An uppermost lens of freshwater, which occupies relatively permeable glacial-outwash sand and gravel to a depth of 520 feet (158 metres), is believed to be in hydrodynamic equilibrium with the present level of the sea and the height of the water table. However, two zones of freshwater at 730 to 820 ft (222-249 m) and 900 to 930 ft (274-283 m) are anomalously deep. Although several explanations are possible, the most likely is that the entire surface of the Continental Shelf was exposed to recharge by precipitation during long periods of low sea level in Pleistocene time. After the last retreat of glacial ice, seawater rapidly drowned the shelf around Nantucket Island. Since then, about 8,000 years ago, the deep freshwater zones which underlie dense clay layers have not had time to adjust to a new equilibrium. Under similar circumstances, freshwater may remain trapped under extensive areas of the Continental Shelf wherever clay confining beds have not permitted saltwater to intrude rapidly to new hydrodynamic equilibria positions. The implications are far reaching because all continental shelves worldwide were exposed to similar hydrologic influences during Pleistocene time.

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USGS1976

The aeromagnetic expression of bedrock geology between the Clinton-Newbury and Bloody Bluff fault zones, northeastern Massachusetts

The pattern of mapped bedrock geology in northeastern Massachusetts bears a striking similarity to patterns of aeromagnetic anomalies in the area. The correspondence of the geology with the anomaly pattern and lineaments on aeromagnetic maps is especially well shown northwest of Boston between the Clinton-Newbury and Bloody Bluff fault zones. Here, an aluminous schist unit and an underlying series of metasedimentary and metavolcanic rocks south of the Clinton-Newbury fault zone coincide with a zone of northeast-trending positive anomalies that contrast with the broad magnetic low north of the fault. Nearly concordant granitic bodies intrude the metamorphic series and correspond to broad magnetic lows between the fault zones. Smaller narrower lows correspond to zones of amphibolite-carbonate rock. Commonly faults are indicated by lineaments that separate areas of different magnetic pattern and that offset or terminate other lineaments. The northeast-trending Spencer Brook and Assabet River fault zones and other unnamed faults are emphasized by magnetic lineaments trending slightly east of the strike of the stratigraphy.

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USGS1975

Hydrologic data of the coastal drainage basins of southeastern Massachusetts, Weir River, Hingham, to Jonas River, Kingston

The principal basins are those of Weir River, James Brook, Bound Brook, North River, South River, and Jones River, all draining to Massachusetts Bay and Cape Cod Bay. These basins are bounded on the north by the Weymouth River basins, on the west by the Taunton River basin, and on the south by small basins that drain to Cape Cod Bay. The basins included all, or parts of, the Norwell, Pembroke, Plymouth, Plympton, Rockland, Scituate, Weymouth, and Whitman. With the following exceptions, each town is served by its own municipal water system--Hingham and northwest Cohasset by the Hingham Water Company; Abington and Rockland by the Abington-Rockland Joint Water Works; and Plympton lacks a public water supply. Weymouth and Cohasset are in Norfolk County; the other towns are in Plymouth County. This report presents, in tabular form, selected records of wells, test wells, borings, and springs; measurements of stream discharge, specific conductance, and temperature at partial-record stations; chemical analyses of ground water and surface water; and a summary of municipal water sources and additional sources available. The data were collected during a study of the drainage basins from 1969 to 1971 in cooperation with the Massachusetts Water Resources Commission. The report is released in order to make available to the public and to local, state, and federal agencies basic hydrologic information that may aid in planning water-resources development. Basic records contained in this report and streamflow data published elsewhere (U.S. Geol. Survey, 1960 et seq.) complement an interpretive report (Williams and Tasker, 1974).

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USGS1975

The megaspore genus Henrisporites from the Cretaceous of Massachusetts

A new megaspore species belonging to the genus Henrisporites was found in Cretaceous (probably Cenomanian) rocks from Massachusetts. Megaspores of Paxillitriletcs dakotaensis (Hall) Hall and Nicolson were found in the same rocks. This paper discusses the occurrence of these two megaspores in North America and describes Henrisporites angustus n. sp. from Massachusetts.

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USGS1974

Surficial geologic map of the Framingham quadrangle, Middlesex and Worcester Counties, Massachusetts

The Framingham quadrangle covers about 55 square miles and is centered approximately 18 miles west of Boston. Even though the major topographic features are controlled by the lithology and structure of the bedrock, glacial features, such as drumlins, kames and kettles, kame terraces, eskers, gently sloping deltas, and flat-lying lake-bottom deposits, have modified the preglacial topography. Some bedrock plucking occurred, especially on the south or southeast sides of some hills, and some valleys probably were deepened. A thin veneer of till overlies much of the bedrock and is most extensive in the hills in the western half of the map area. These deposits, which are mostly gently sloping kame deltas or flat-lying lake-bottom deposits, were laid down in or graded to glacial Lakes Charles (Clapp, 1904, p. 198) and Sudbury (Goldthwait, 1905, p. 274), which formed during deglaciation when melt waters were temporarily impounded. Some glacial-lake deposits were laid down in three smaller higher level lakes in the western part of the quadrangle. With the exception of a small part of the southeast corner, which is drained by the Charles River, the quadrangle is drained by the Sudbury River, whose waters eventually flow into the Merrimack River in the northeast part of the state.

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