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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 49 (1965)

Issue: 3. (March)

First Page: 346

Last Page: 346

Title: Paleocurrents and Oceanography: ABSTRACT

Author(s): George DeVries Klein

Article Type: Meeting abstract


The rationale of paleocurrent studies suggests that directional current structures identify the provenance, transport direction, basin architecture, and paleoslope of sedimentary sequences. Numerous examples from fluvial deposits have reinforced this view.

In marginal marine environments, directional current structures are fashioned by a combination of tidal, wave, and wind-driven currents which flow randomly with respect to slope and sediment source. Directional structures formed by these currents are oriented perpendicular or parallel to both slope and sediment source. The resulting structures, therefore, reveal only the direction of transport of the last current to act upon the sediments prior to burial.

The direction of flow of bottom-scouring currents in continental shelves and deep ocean basins is determined by changes in density, temperature, and salinity, by wind action, and by the rotation of the earth. Such changes tend to drive currents in random directions in the ideal case, but because of the earth's rotation, most ocean currents flow parallel to topographic strike. Resulting directional current structures of shelf and deep marine sediments cannot define paleoslope or provenance, but they do define topographic strike.

Because the direction of flow of ocean currents depends on many variables, several combinations of current systems can be recognized, including converging systems, diverging systems, and stratified systems. Where two currents converge, one system will override the other system because of differences in density. Converging directional data have been reported from ancient turbidites, indicating that similar converging current systems existed in the past. These data also suggest that many "turbidite" directional criteria were formed by bottom scouring ocean currents.

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Copyright 1997 American Association of Petroleum Geologists