OF 02-152 Home
DVD-ROM
Contents
Geologic
Discussion
GIS Data
Contacts
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Conclusions
This report presents a synthesis
of results obtained from systematic high-resolution mapping of the
sea floor of the New York Bight, principally by means of 100%-coverage
sidescan sonar and seismic-reflection methods. The resulting maps
offer detailed views of the sea floor, and provide a new framework
for understanding the sedimentary evolution of the inner continental
shelf. This new framework is essential for understanding the regional
sediment-transport system of the New York Bight. Our interpretation
of the subbottom data shows that: (1) a regional unconformity truncates
the Late Cretaceous to early Tertiary coastal-plain strata and the
topographic relief of this unconformity has controlled the accommodation
space for subsequent deposition of Pleistocene sediment; (2) the
Pleistocene sedimentary deposit is relatively thin, with the exception
of areas where sediment-filled paleofluvial channels cut into the
underlying Late Cretaceous to early Tertiary coastal-plain strata;
(3) the Holocene sedimentary deposit is extremely thin and composed
of sediment reworked from Pleistocene and Late Cretaceous to early
Tertiary coastal-plain deposits during the last marine transgression,
and; (4) Pleistocene and Late Cretaceous to early Tertiary strata
crop out on the continental shelf and continue to be reworked by
oceanographic processes. The sidescan-sonar images of the New York
Bight provide an acoustic view of the formation, or active modification,
of a ravinement surface formed by Holocene transgression. The maps
and interpretations presented in this report verify and clarify
preliminary interpretations of sidescan-sonar imagery collected
in the New York Bight proposed by Schwab and others (1997a, 1997b,
2000a).
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