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Virginia Institute of Marine Science
George Dellagiarino, Lynda A. Miller, and Susann Doenges
Proceedings Fourth Symposium on Studies Related to Continental Margins - A Summary of Year-Nine and Year-Ten Activities
Bureau of Economic Geology, University of Texas at Austin
Virginia’s Year-Nine and Year-Ten funds from the Continental Shelf Program were used to supplement other work funded by the Minerals Management Service in an ongoing Cooperative Agreement focused on the area offshore of southeastern Virginia. Year-Nine and Year-Ten funds facilitated interpretation of subbottom profiles and the analysis of sediment samples from cores and grabs. On Virginia’s sediment-starved continental shelf, deposits of material potentially suitable for use as beach nourishment or, perhaps, as construction aggregate occur in three stratigraphic settings, each with specific characteristics of morphology, grain-size gradients, likelihood of discovery, and physical ease of exploitation. All must be verified with a careful program of coring. Modern shoals generally are easier to identify, prove, and access than either filled channels or lenticular facies. Shoals usually are identifiable on nautical charts and characteristically have a definite lower boundary that can be seen in subbottom profiles. In most cases, the base of the shoal coincides with the level of the surrounding sea floor. Filled channels are readily identifiable on subbottom profiles but may have a narrow, sinuous form and steep lateral gradients in sediment properties. Buried lenticular facies of good-quality sand usually are found only fortuitously. As the lateral and often vertical gradients in geotechnical properties usually are low, the lenticular facies can be mined with a lesser concern for the consequences of violating the deposit’s limits than with the other two types of deposit. (more ....)
Continental margins, coasts, geology
Hobbs, Carl III; Hardaway, C. Scott Jr.; and Berquist, C. R., "Submarine Sand Resources, Southeastern Virginia - Contributions from Year Nine and Year Ten of Virginia’s Continental Margins Program" (1998). VIMS Books and Book Chapters. 123.