amounts of chlorite and small concentrations of kaolinite present (Bothner and 
others, 1979). Montmorillonite is present only in trace amounts or is 
absent. The origin of the illite and chlorite in the clay fraction is thought 
to be unweathered material eroded from Paleozoic and older rocks in the 
northern Appalachian region transported to the Continental Shelf during 
glacial periods (Hathaway, 1972). 
The concentration of gravel is variable, ranging from 0 to almost 20 
percent (appendix table 3A). The gravel is composed of rock fragments or 
shell hash or a mixture of both. Drill cuttings were observed in the gravel 
fraction at the drill sites in blocks 312 and 410. A few cuttings were found 
at station 17, 2 km to the east of the drill site in block 410 during both 
year 2 and year 3. On cruise 9, cuttings were observed at all stations within 
500 m of the drill site in block 312. The cuttings are angular; they range in 
size from 2 to 8 mm and most are gray in color. Using X-ray diffraction 
analysis on a few cuttings, L. J. Poppe (USGS, written commun., 1984) 
identified calcite as the predominant mineral with lesser amounts of dolomite 
and layered silicates. These are common minerals throughout the subsurface 
Jurassic and Cretaceous sediments (Arthur, 1982). The highest concentrations 
of cuttings, which were localized at the drill sites, represent less than 
1.5 percent of the total sample weight. The cuttings did not occur in a 
recognizable pile in the vicinity of the drill site in block 312, according to 
R. A. Cooper, National Marine Fisheries Service (written commun., Oct. 14, 
1983), who conducted visual and photographic surveys of the drill site from a 
submersible. 
Trace metals in bulk sediments 
During the first year of this program, we established that’ the 
concentrations of trace metals in sediments collected before drilling began 
25) 
