About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 67 (1983)

Issue: 3. (March)

First Page: 538

Last Page: 538

Title: Lower Cretaceous Wabiskaw Tar Sands: Shallow Shelf Reworking of Submarine Fans: ABSTRACT

Author(s): Mike Ranger, Robert Sharpe

Article Type: Meeting abstract

Abstract:

The Wabiskaw Sands consist of 3 units, each of which is a mappable submarine fan complex. They prograded westward into a shallow basin, 50 to 60 m (164 to 200 ft) deep, that existed during the early part of the Lower Cretaceous transgression. Each fan complex was fed by a different submarine canyon. These canyons were drainage valleys on the Paleozoic erosion surface before they were drowned by the marine transgression. Each fan complex covers 6,000 to 7,000 km2 (2,300 to 2,700 mi2) and each was probably related to a progressively higher sea level stand.

Once on the basin floor, the sand was reworked by storms and possibly tides, and now has the characteristics of a shallow shelf bar similar to the Upper Cretaceous Hygiene Sand of Colorado or Sussex Sand of Wyoming. Each of the three Wabiskaw sequences coarsen upward. They are strongly bioturbated at the base, decreasing to only slight bioturbation in the upper sandy facies, in which Asterosoma is the most common trace fossil. These glauconitic sands are dominated by tabular bedding or large, shallow, trough cross-bedding when physical structures are visible; otherwise the sands appear massive.

A bar morphology is apparent from data from closely spaced (215 m; 700 ft) wells, and reservoir parameters such as porosity and permeability broadly reflect this pattern.

End_of_Article - Last_Page 538------------

Copyright 1997 American Association of Petroleum Geologists