Composition and Distribution of Macrobenthic Invertebrate Fauna 



NEW \ NEW 



JERSEY \ YORK/ 



NEW 



JTORK 



GRAVEL 

 SHELL 

 TILL 

 SAND 



E;;jj;;[ silty sand 



2] SILT-CLAY 



40° 



Figure 7 

 Geographical distribution of bottom-sediment tvpes in the stud) area. 



Bottom Sediments 



The composition of sediments blanketing the sea floor 

 throughout the study area is well known. Detailed stud- 

 ies have included sedimentological aspects of general 

 lithology, particle size composition, calcium carbonate 

 content, organic carbon content, nitrogen content, 

 minerology, sand and gravel fractions, and other com- 

 ponents. A representative selection of publications deal- 

 ing with the bottom sediments of New England marine 

 waters includes: Shepard, et al. (1934) ; Shepard and Cohee 

 (1936); Stetson (1936, 1938, 1949); Shepard (1939); 

 Hough (1940, 1942); Wiglev (1961a); Uchupi (1963, 

 1965b, 1966a. 1966b. 1966c, 1968, 1969); Emery (1965a, 

 1965b, 1966a, 1966b, 1968); Emerv et al. ( 1965); Rvac hev 

 ( 1 965) ; Garrison and McMaster ( 1 966) ; Hiilsemann ( 1 966, 

 1967); McMaster and Garrison (1966); Ross ( 1967, 1970a, 

 1970b); Uchupi and Emery ( 1967); Emery and Ross (1968); 

 Schlee (1968, 1973); Schlee and Pratt ( 1970); Emery and 

 Uchupi (1972); Trumbull (1972); Mtlliman (1973); Wigley 

 and Stinton ( 1973); Sheridan ( 1974); Austin et al. ( 1980); 

 Twichell et al. (1981); Butman (1982, 1987); Klitgord et. 

 al. (1982); and Valentine etal. (1980). 



Relict glacial sediments are the major constituents cov- 

 ering most of the study area, particularly on the continen- 

 tal shelf. Quart/ and feldspar sands and granite and gneiss 

 gravels are particularly common in the shallower areas 

 and on the topographically high elevations in deeper 

 water. Fine-textured sediments, mainly silts and clays, that 

 mantle the continental slope, continental rise, and pro- 

 tected pockets and basins on the continental shelf are 

 predominantly present-day detrital sediments. 



Large areas in the deeper part of the Gulf of Maine 

 are floored with unsorted glacial till, whereas the shal- 

 low banks and ridges are commonly covered with gravel 

 or sand of glacial origin that remained after washing 

 action removed the finer particles. In some deep parts 

 of the Gulf, where water currents are minimal, the till is 

 overburdened with layers of silt and clav. In Long Is- 

 land Sound, Buzzards Bay, and many of the smaller 

 bays along the coast, the sediments are composed largely 

 of silts and clays, with sand and gravel common in the 

 nearshore zones. 



The sediment chart prepared for this report (Fig. 7) 

 is based on sediment samples taken from the same grab 

 hauls from which the fauna was obtained. 



