Geomorphology and Sediments of Western Massachusetts Bay

Abstract

Source: https://erdc-library.erdc.dren.mil/jspui/A seismic reflection survey with concurrent bottom sampling was conducted in western Massachusetts Bay to obtain information on bottom topography and sediments, subbottom structure and composition, and the location of sand deposits potentially usable for restoration and nourishment of nearby beaches. Primary data consisted of 242 statute miles of seismic reflection survey and 43 sediment cores. Seismic reflection profiles show that most of the area is underlain by a rock mass with a highly irregular surface below which no coherent reflections appear on available records. Highs in this unit outcrop in places while lows are either partly or completely filled with acoustically transparent material having internal reflection patterns which indicate a stratified deposit. Cores and extrapolation from onshore outcrops indicate that the lower unit consists of dissected basement complex rocks overlain in places by glacial drift and the upper (transparent) unit consists mainly of Pleistocene glaciomarine and Holocene sediments. The predominant sediments of the surface and shallow subsurface (less than 15 feet) deposits in the study area are fine sand, sand and gravel, and clayey silt. Sand suitable for beach restoration and nourishment on the. contiguous coast occurs only locally and in generally small quantity relative to other sediments of the study area. Seven potential borrow sites are located and discussed