A portable, self supporting, hydraulic vibracorer for coring submerged, unconsolidated sediments

Dokken, Quenton R.; Circe, R.C.; Holmes, C. W.

doi:10.1306/212f77f7-2b24-11d7-8648000102c1865d

Cited by 6 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Samples of the sand deposits were obtained by means of a vibracoring device specifically designed for carbonate sands by Dokken and others [5]. Radiometric analyses (U, Th, and Pb) were made on samples from three cores by standard chemical procedures and the final assay was made by alpha spectroscopy.…”

Section: Methodsmentioning

confidence: 99%

210Pb method for estimating the rate of carbonate sand sedimentation

Holmes

1981

Geo-Marine Letters

View full text Add to dashboard Cite

The plot of 21~ activity against depth in carbonate sands on the Virgin Island Bank is a negative asymmetric hyperbolic curve. As depth increases, an initial rapid decrease in 21~ activity caused by the decay of unsupported 21~ and 226Ra is followed by increasing activity as a result of 21~ achieving equilibrium with ingrowing 23~ As this curve is time dependent, an estimate of the relative ages in carbonate sequences and the rates of net carbonate accumulation can be made. The base of 21~ activity determinations makes this procedure an attractive method in obtaining carbonate sand accumulation rates.

show abstract

Section: Methodsmentioning

confidence: 99%

210Pb method for estimating the rate of carbonate sand sedimentation

Holmes

1981

Geo-Marine Letters

View full text Add to dashboard Cite

show abstract

“…-•c: Subsurface sampling (fig. 6) was done by using a Dokken-Circe vibracorer (Dokken et al, 1979). The cores were 6 em in diameter and had an average length of 5 m. The cores were split in the laboratory, and approximately 50-g subsamples were taken every 25 em for the first meter and every 50 em thereafter.…”

Section: ~ ~Hansmentioning

confidence: 99%

Sedimentology of Southwestern Roads region, U.S. Virgin Islands: Origin and rate of sediment accumulation

Miller¹,

Holmes²,

Kindinger³

1980

Open-File Report

View full text Add to dashboard Cite

Sand deposits on the southern shelf of the U.S. Virgin Islands were investigated to determine their origin and to relate origin to environmental processes and production rates. Analysis of sea-floor samples for composition shows that the sand has been derived mainly from calcareous algae and molluscs in situ. Zonation of the dominant sand producers is related to the present environmental setting; water depth has the greatest influence.Carbon-14 dating of cores as long as 5 m indicates accumulation rates of slightly less than 1 mm/year for the last 5,000 years in areas of thickest sand. Faunal studies show that the climate during the last 5,000 years was similar to that of today. The only changes in environmental conditions appear to have been an increase in water depth and a concurrent change in the patterns of water movement. In areas protected during lower sea level, the subtidal barnacle, ~alanus venustus, disappeared and the amount of coralline algae in the sediment gradually increased beginning approximately 1,500 years ago. The disappearance of the barnacles probably was caused by the introduction of open-marine conditions into a previously protected lagoonal area. On the other hand, the articulate coralline algae increased in the quiet waters on the lee side of the offshore islands because of the change in habitat created by deepening waters.

show abstract