Physical Sciences and Mathematics Commons^™

Heavy Mineral Concentrations In Sediments Of The Virginia Inner Continental Shelf, C. R. Berquist Jr., C. T. Fischler, L. J. Calliari, Et Al

VIMS Books and Book Chapters

The Virginia Division of Mineral Resources and the Virginia Institute of Marine Science investigated the occurrence of heavy minerals in the offshore sediments of Virginia. We began the project because earlier reconnaissance studies reported high heavy-mineral concentrations from several samples collected off the Eastern Shore of Virginia. Our work confirms the previously reported mineral values and locates additional high concentrations up to 20 nautical miles offshore. Furthermore, we show that potentially economic mineral values are not restricted no surficial sediments, but also are found in the upper 15 to 20 feet of inner continental shelf sediments. Several core samples indicate …

Heavy Mineral Variability And Provenance Of The Virginia Inner Shelf And Lower Chesapeake Bay, L. J. Calliari, C. T. Fischler, C. R. Berquist Jr.

VIMS Books and Book Chapters

The mineral composition of the 3- to 4-phi (0.125 to 0.063 mm) size fraction of 49 surficial grab samples,located north and south of the entrance to Chesapeake Bay and of 38 surficial samples, located in the bay mouth, was determined during this study. Although up to 17 minerals were identified, principal components analysis indicated that seven minerals accounted for 96 percent of the composition variance in the bay samples. By using Q-mode factor analysis, three mineral composition end-members (factors) were selected from the sample data and provided an adequate description of the spatial variation in heavy-mineral composition. The end members …

A Procedure For Assessing Heavy Mineral Resources Potential, Andrew E. Grosz, C. R. Berquist Jr., C. T. Fischler

VIMS Books and Book Chapters

Supplies of placer heavy minerals, such as ilmenite, rutile, zircon, and monazite, are anticipated to be in short supply by early in the next century. The depletion of conventional onshore deposits coupled with the declaration of the Exclusive Economic Zone in 1983 have provided the impetus to assess the resource potential of heavy-mineral concentrations in U.S. Continental Shelf sediments as future sources for these mineral commodities.

Mineralogically imprecise assessments of placer resources result from analyses of concentrates derived from small volume samples because of the particle-sparsity effect. The overall low grade of heavy minerals in Atlantic Continental Shelf sediments require …

Sandy Estuarine Fill Transported Into The Mouth Of Chesapeake Bay, C. H. Hobbs Iii, S. M. Cohen, C. R. Berquist

VIMS Books and Book Chapters

The landward flux of sand into an estuary is a process that is seldom documented or quantified, yet is important to the sedimentary dynamics of a maturing estuary. Data from three recent studies converge to demonstrate the transport of sand into Chesapeake Bay from the adjacent shelf. A 100- year sediment budget, distributions of heavy minerals, and seismic-reflection data all point to the bay mouth as a gate through which a significant quantity of sand enters the estuarine system.

Sediments Of The James River Estuary, Virginia, Maynard M. Nichols

VIMS Books and Book Chapters

The James River estuary of the Chesapeake Bay region follows the course of a former river valley drowned within the last 9,000 years by the most recent rise of sea level. The floor is shaped into a central channel bordered by submerged shoals. Observations show suspended sediment is transported mainly by alternating tidal currents and secondarily by the net nontidal estuarine circulation. Transport results in a sequence of grain size distributions reflecting the mixing of two textural end members, clay and sand.

Silty clay is deposited in the river and upper estuary, whereas sand occurs near the mouth. Transitional types, …