Genesis and modification of the sand ridges : Inner and middle New Jersey shelf, U.S.A. /
Bathymetric, geophysical, textural, and paleontological data provide evidence for the genesis and modification of sand ridges on the New Jersey continental shelf. In a 37 km wide corridor extending 65 km seaward from Atlantic City, New Jersey, 551 surficial grab samples, 12 vibracores, and 291 km of...
| Main Author: | |
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
[College Station, Tex.] :
Stubblefield,
1980.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy Link to ProQuest copy |
| Summary: | Bathymetric, geophysical, textural, and paleontological data provide evidence for the genesis and modification of sand ridges on the New Jersey continental shelf. In a 37 km wide corridor extending 65 km seaward from Atlantic City, New Jersey, 551 surficial grab samples, 12 vibracores, and 291 km of 3.5 kHz seismic data were collected. Closed contours of ridges on the bathymetric map reveal three sets of ridges. Nearshore ridges intersect the coastline at 20° to 30° (nearshore coast-oblique). Seaward of these is a 30 km wide ridge complex with ridges approximately coast-parallel (mid-shelf coast-parallel). Still farther seaward are ridges which trend approximately parallel to the nearshore coast-oblique ridges and thus intersect the mid-shelf coast-parallel ridges at 20°to 30° (outer mid-shelf coast-oblique). Cores taken from the nearshore ridges reveal a medium grain sand which may either coarsen upward or be of uniform texture. Similar cores from the mid-shelf indicate these ridges consist of fine grains and which coarsens upward. Approximately the upper one meter of the mid-shelf ridges consists of coarser sand. The distribution of surficial sediments over the nearshore ridges is asymmetrical in terms of grain size. The sands are coarsest on the shoreward flank and fine toward the seaward flank. On the mid-shelf coast-parallel ridges the surficial sand distribution is more symmetrical with the coarsest fraction on the upper shoreward flank. The macrofauna from the nearshore ridges are those of shallow, open marine and are data as being younger than 700 years B.P. The micro and macrofauna from the seaward edge of the mid-shelf coast-parallel ridges are characteristic of open water, shallow marine but those from the shoreward edge are species typical of both brackish and open marine waters. The macrofauna from the mid-shelf ridges range in age from <500 to >36,000 years B.P. These data indicate two ridge types are found on the New Jersey continental shelf. The mid-shelf coast-parallel ridges are interpreted as degraded, submerged paleobarriers. The nearshore coast-oblique and outer mid-shelf coast-oblique ridges formed as shoreface-connected ridges at the foot of a barrier... |
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| Item Description: | Vita. "Major subject: Geology." |
| Physical Description: | xv, 246 leaves : illustrations, maps, graphs ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 216-225). |