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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 66 (1982)

Issue: 5. (May)

First Page: 570

Last Page: 570

Title: Origin of Mid-Atlantic Barrier Islands and Implications for Petroleum Exploration: ABSTRACT

Author(s): Cyril Galvin

Article Type: Meeting abstract

Abstract:

The resemblance in plan between Cherokee shoestring sands in southeast Kansas and existing barrier islands around the New York Bight suggests that a genetic interpretation of Mid-Atlantic barrier islands may aid in exploration and development of linear oil-bearing sands. Mid-Atlantic barrier island chains are elongate sand bodies with typical dimensions of 5 to 25 mi (8 to 40 km) alongshore, less than 1 mi (1.6 km) across shore, and 10 to 40 ft (3 to 12 m) thick. These barrier islands develop and are maintained by the wave-driven longshore distribution of sands from a source. For Mid-Atlantic barrier islands, there are no rivers acting as sediment sources and the direct contribution of eroding bluffs is relatively unimportant. For the most part, the sources of the sand ar the existing beach and nearshore. Shoreline changes over the past 200 years show that the longshore distribution is episodic, probably reflecting shifts in angle of wave attack or the uncovering of previously buried nearshore sand bodies more than sea-level rise. The historic charts clearly show that large sand deposits overwhelm any sea-level rise effects on a time scale of decades to centuries (Fire Island, Sandy Hook, Fishing Point, and others). These sand bodies advance onto and are backed by relatively fine-grained material with a high organic content, suggesting that source material is not lacking. They will have a relatively good chance of being preserved in the rock record under prevailing transgressive conditions. Of immediate use for petroleum exploration is the center-line of set of individual barriers within the chain. Center lines of the largest and most active barriers extend seaward of smaller barrier islands on the downdrift side. Also, barrier islands develop toward the low latitudes, reflecting the effect of waves generated by storms in the high latitude seas. Barrier islands on a worldwide basis appear limited to the leeward side of continental land masses.

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Copyright 1997 American Association of Petroleum Geologists