About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 946

Last Page: 946

Title: Hydrocarbon Exploration on Ancient Shelf-Slope Breaks: ABSTRACT

Author(s): WM. C. Krueger, Jr.

Article Type: Meeting abstract


A general set of traps, reservoirs, and seals occurring on the shelf-slope break can be hypothesized based on the structural regime, provenance, and width and slope of the shelf. To evaluate this break is to look at the entire region--shelf and slope.

With a wide or moderately wide shelf, gentle slope, and peneplaned provenance, carbonate sediments would dominate in marine environments. Logically, a reefal environment (reservoir) would be expected at the shelf slope. Conversely, with a narrow shelf and a positive continental borderland in close proximity, terrigenous clastics would be expected. Deltaic-like reservoirs could be expected on the shelf; turbidites would logically occur downslope. A broad shelf with a positive provenance could inspire various lithologic deposition (depending on the environment)--reefal at the shelf-slope area, deltaic or lagoonal behind, and turbidites in front.

Examples of such former reservoirs are Empire-Abo reef trend of Texas-New Mexico; Cretaceous Stuart City shelf margin of Texas; Golden Lane-Pozo Rica trends of Mexico; Miocene pinnacles of the Salawati basin, Irian Jaya; and Kirkuk field on the Arabian Platform.

Penultimate reservoirs are the linear sands of the San Joaquin and Ventura basins; Oligocene sands of south Louisiana; Triassic sands of the North Sea basin; Cretaceous Seaway sands in the Powder River basin; and the ancient Mississippi delta and cone. Latter reservoirs are found in the eastern shelf, Midland basin, and Bombay offshore basin, India.

It is understood that for some of these reservoirs to become traps, the founding structural regime is modified, e.g., faulting, diapirism. Seals are classed as carbonate muds, evaporites, and faults. Source matter may be incorporated in marine shale and limestone deposited in anoxic environments.

End_of_Article - Last_Page 946------------

Copyright 1997 American Association of Petroleum Geologists