Skip Links

USGS - science for a changing world

Open-File Report 2014–1160

Prepared in cooperation with the National Oceanic and Atmospheric Administration

Sea-Floor Morphology and Sedimentary Environments of Western Block Island Sound, Northeast of Gardiners Island, New York

By Katherine Y. McMullen, Lawrence J. Poppe, William W. Danforth, Dann S. Blackwood, Andrew R. Clos, and Castle E. Parker

Thumbnail of and link to report PDF (10.4 MB)Abstract

Multibeam-echosounder data, collected during survey H12299 by the National Oceanic and Atmospheric Administration in a 162-square-kilometer area of Block Island Sound, northeast of Gardiners Island, New York, are used along with sediment samples and bottom photography, collected at 37 stations in this area by the U.S. Geological Survey during cruise 2013-005-FA, to interpret sea-floor features and sedimentary environments. These data and interpretations provide important base maps for future studies of the sea floor, focused, for example, on benthic ecology and resource management. The features and sedimentary environments on the sea floor are products of the glacial history and modern tidal regime. Features include bedforms such as sand waves and megaripples, boulders, a large current-scoured depression, exposed glaciolacustrine sediments, and areas of modern marine sediment. Sand covers much of the study area and is often in the form of sand waves and megaripples, which indicate environments characterized by coarse-grained bedload transport. Boulders and gravelly lag deposits, which indicate environments of erosion or nondeposition, are found off the coast of Gardiners Island and on bathymetric highs, probably marking areas where deposits associated with recessional ice-front positions, the northern flank of the terminal moraine, or coastal-plain sediments covered with basal till are exposed. Bottom photographs and video of boulders show that they are commonly covered with sessile fauna. Strong tidal currents have produced the deep scour depression along the northwestern edge of the study area. The eastern side of this depression is armored with a gravel lag. Sea-floor areas characterized by modern marine sediments appear featureless at the 2-meter resolution of the bathymetry and flat to current rippled in the photography. These modern environments are indicative of sediment sorting and reworking.

First posted August 27, 2014

For additional information, contact:
Director, Woods Hole Coastal and Marine Science Center
U.S. Geological Survey
384 Woods Hole Road
Quissett Campus
Woods Hole, MA 02543
http://woodshole.er.usgs.gov/

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. More information about viewing, downloading, and printing report files can be found here.


Suggested citation:

McMullen, K.Y., Poppe, L.J., Danforth, W.W., Blackwood, D.S., Clos, A.R., and Parker, C.E., 2014, Sea-floor morphology and sedimentary environments of western Block Island Sound, northeast of Gardiners Island, New York: U.S. Geological Survey Open-File Report 2014–1160, 1 DVD-ROM, https://dx.doi.org/10.3133/ofr20141160.

ISSN 2332–4899 (DVD)

ISSN 2331–1258 (online)



Contents

Abstract

Introduction

Setting

Methods

Bathymetry

Sediments

Bottom Photography

GIS Data Catalog

Summary

Acknowledgments

References Cited

Contacts


Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: https://pubs.usgs.gov/of/2014/1160/
Page Contact Information: Contact USGS
Page Last Modified: Wednesday, December 07, 2016, 07:38:42 PM