Accession Number:

ADA609714

Title:

Modeling Sedimentary Deposits on the Continental Margin

Descriptive Note:

Annual rept.

Corporate Author:

OLD DOMINION UNIV NORFOLK VA DEPT OF OCEANOGRAPHY

Personal Author(s):

Report Date:

2000-09-30

Pagination or Media Count:

6.0

Abstract:

The long-term goal of my research group is to construct mathematical descriptions of the processes that form sedimentary deposits at all spatial scales on continental margins, from storm beds to the deposits of 100,000 yr sea level cycles, and to conduct numerical experiments leading to the prediction of the sedimentary fabric structure and stratification pattern of the resulting deposits. We are undertaking this work in collaboration with our subcontractors, Alan Niedoroda and Chris Reed, at URL Greiner, Tallahassee. A first objective is to investigate the fabric pattern of seabed stratification on continental margins at small time and space scales 1 cm-50 cm depth into the seabed 1 hr-3 yr sedimentary record. To this end, we are testing the hypothesis that on muddy shelves such as the northern California shelf, Holocene event stratigraphy consists of the deposits of high-concentration storm regimes associated with river floods, alternating with deposits of low-concentration storm regimes. At intermediate spatial scales 1 -20 m depth into the seabed 1-1,000 yrs, we are testing a second hypothesis. The hypothesis states that facies assemblages are stacked on, or are capped by, erosional bounding surfaces source diastems, in patterns reflecting fluid power gradients in the parent dispersal system and that these patterns are responses to progressive sorting and stratal condensation mechanisms. At large time and space scales 1 -1,000 m depth into the seabed 100-2.5 million yrs we are testing a third hypothesis. The hypothesis states that that depositional sequences can be explained in terms of shifts in the equilibrium configuration of shelf surface in response to changes in sea level, the rate and character of sediment input, and the hydrodynamic climate.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Geology, Geochemistry and Mineralogy
  • Hydrology, Limnology and Potamology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE