S. Jeffress Williams

Upper Quaternary peat deposits on the Atlantic inner shelf of the United States

Twenty-one upper Quaternary peat samples have been obtained from vibracores collected along the inner continental shelf of the Atlantic coast of the United States. Radiocarbon ages and pollen identifications from the peats, coupled with those from onshore borings and published data, provide additional information on the latest history of the Atlantic shelf. The radiocarbon ages cluster in two groups: early and middle Holocene time (10,000 to 5,000 B.P.) and late Pleistocene time (35,000 to 20,000 B.P.). Although ages and depths of the upper Pleistocene peats show some agreement with published graphs of changes in sea level, pollen data indicate that most of the peats formed in terrestrial environments and therefore may be unreliable as indicators of sea level. The Holocene peats were deposited in both marine and terrestrial environments. Correlation of the stratigraphic sequences in the cores containing peat with high-resolution seismic reflection profiles indicates a history of transgressive erosion on the inner shelf. Only remnants of carbonaceous sediments originally deposited in bogs, ponds, estuaries, and salt-marsh lagoons are present in the shallow subsurface on the inner shelf. These remnants, which are discontinuous and usually associated with erosional unconformities, provide evidence of regional marine planation of the shelf by the rising Holocene sea.

Geological character and mineral resources of south central Lake Erie / by S. Jeffress Williams and Edward P. Meisburger.

Abstract : During the summers of 1977 and 1978, a 900-square kilometer region of southern Lake Erie, between the Ohio-Pennsylvania border and Erie, Pennsylvania, was surveyed, using high resolution seismic reflection equipment and long vibracores, to determine the shallow subbottom geologic character of the lake floor. Emphasis was placed on describing the sediments and identifying deposits of sand and gravel that might be dredged and used as fill for beach nourishment projects on Presque Isle Peninsula. A total of 416 kilometers of seismic profiles and 49 cores with an average length of 4.1 meters were analyzed along with 23 grab samples.

Use of vibratory coring samplers for sediment surveys / by Edward P. Meisburger and S. Jeffress Williams.

Abstract : The vibratory coring apparatus was developed about 30 years ago by Soviet engineers to increase existing capabilities to penetrate and recover cohesionless soil samples. In 1963, the original Soviet design was used by personnel at Alpine Geophysical Associates, Inc., to fabricate a system to recover 20-foot-long (6 meters) cores for use in CERCs sand inventory program, later known as the inner Continental Shelf Sediment and Structure (ICONS) program. The core apparatus has since been improved to recover up to 40-foot-long (12 meters) continuous cores in water depths to -60 feet (-18 meters), and is now widely used in oceanographic work. The CERC experience consists of more than 1,600 cores collected in 15 surveys along the Atlantic, gulf, and Pacific coasts, as well as Lakes Michigan and Erie. This experience in obtaining, handling, and sampling cores for sedimentological analysis is presented to aid others in conducting geologic and engineering studies using the vibracore. (Author)