Sand and gravel resources: U.S. Atlantic continental shelf
Sand and gravel epitomize bulk commodity; that is, they are consumed in large volume, are relatively plentiful with low unit cost, and transportation costs from source to market are the chief limiting factors when considering alternate supplies. For the United States Atlantic continental margin, sand and gravel deposits are associated with Pleistocene to Recent fluvial or ice contact processes modified by marine processes. Prospective sources represent a continuum from the limit of the fall line, across the present coastline, to the shelf edge near the limit of the Pleistocene low stand shoreline.
With a few localized exceptions in the New York City vicinity, terrestrial sources have traditionally supplied the market. Along the heavily urbanized sectors—which constitute much of the coastal area from Miami, Florida, north to Boston, Massachusetts—dwindling resources on land, coupled with increasing urbanization and terrestrial environment preservation, have stimulated consideration of marine deposits of the continental shelf as replacement resources for terrestrial supplies. Projecting a near-future time when, for one of several reasons, terrestrial sources are no longer available to this coastal sector, the focus of this review is on marine sand and gravel.
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The Atlantic Continental Margin
This synthesis covers stratigraphy, depositional processes, and geophysical interpretation of the major onshore and offshore marginal basins from Maine to the Bahamas, and includes an up-to-date review of thinking on regional tectonic history. Additional chapters discuss the theoretical aspects of thermal evolution, subsidence, and seismic stratigraphy as applied to this region. Geological resources including petroleum, water, sand and gravel, hard minerals, and heat flow are reviewed, and environmental hazards such as seismicity, coastal erosion, waste disposal and submarine instability as it relates to site of drilling platforms and mining are evaluated. A summary chapter reviews areas of controversy and suggests key topics for research.