Sediments of the Continental Margin off the Eastern United States

Abstract

Research Article| May 01, 1972 Sediments of the Continental Margin off the Eastern United States JOHN D MILLIMAN; JOHN D MILLIMAN Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 Search for other works by this author on: GSW Google Scholar ORRIN H PILKEY; ORRIN H PILKEY Department of Geology and Marine Laboratory, Duke University, Durham, North Carolina 27706 Search for other works by this author on: GSW Google Scholar DAVID A ROSS DAVID A ROSS Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 Search for other works by this author on: GSW Google Scholar Author and Article Information JOHN D MILLIMAN Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 ORRIN H PILKEY Department of Geology and Marine Laboratory, Duke University, Durham, North Carolina 27706 DAVID A ROSS Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 Publisher: Geological Society of America Received: 18 Oct 1971 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1972, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1972) 83 (5): 1315–1334. https://doi.org/10.1130/0016-7606(1972)83[1315:SOTCMO]2.0.CO;2 Article history Received: 18 Oct 1971 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation JOHN D MILLIMAN, ORRIN H PILKEY, DAVID A ROSS; Sediments of the Continental Margin off the Eastern United States. GSA Bulletin 1972;; 83 (5): 1315–1334. doi: https://doi.org/10.1130/0016-7606(1972)83[1315:SOTCMO]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The character and distribution of surficial sediments on the continental shelf and slope between northern Maine and southern Florida have been denned on the basis of more than 6,000 bottom samples. Most shelf sediments were deposited in shallow water (probably littoral depths) during the last lower stand of sea level. Modern sediments are accumulating only in estuaries, in certain nearshore areas and on the continental slope.A large portion of the shelf sediment north of lat 41° N. was deposited by Pleistocene glaciers that covered the area. Sediments on the middle Atlantic shelf consist of predominantly arkosic to subarkosic fluvial sands. The inner shelf off the southeastern United States is covered by suborthoquartzitic fluvial sands, derived mostly from Piedmont rivers; carbonate-rich sands occur over much of the outer shelf and upper slope. Residual detritus, reworked from underlying mid-Tertiary formations, is an important sedimentary component on Georges Bank and Nantucket Shoals, Onslow Bay, the Florida-Hatteras slope, and the Blake Plateau.Although most sediments are not in compositional equilibrium with the present-day shelf environment, there is considerable evidence to suggest that many may be in at least partial textural equilibrium. Holocene reworking has removed most fine-grained sediment, leaving only coarse to medium sand. Some fine-grained fluvial sediment escapes the estuaries and near-shore during floods and storms, but this influx is not sufficient to offset the effect of winnowing by currents and waves. A significant portion of the modern near-shore sediment, in fact, may be derived from landward transport of fine-grained sediment from the central and outer shelf. Despite the evidence of active sediment movement on the shelf, however, the net lateral transport of sand and gravel appears to be limited.Because of the lack of present-day terrigenous sedimentation, a primary source of modern shelf sediment is calcareous skeletal material. If the present-day surface were preserved in the geologic record, much of it probably would be a carbonate-rich layer, containing altered and reworked skeletal material representing a variety of depositional environments. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.