About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

Journal of Sedimentary Research (SEPM)

Abstract


Journal of Sedimentary Research, Section A: Sedimentary Petrology and Processes
Vol. 64A (1994)No. 2. (April), Pages 282-298

Ripple Marks in Quartz Arenites of the Hurwitz Group, Northwest Territories, Canada: Evidence for Sedimentation in a Vast, Early Proterozoic, Shallow, Fresh-Water Lake

Lawrence B. Aspler (1), Jeffrey R. Chiarenzelli (2), Terry L. Bursey (3)

ABSTRACT

Supermature quartz arenites of the Whiterock Member, deposited in the Early Proterozoic, intracratonic Hurwitz Basin, have a maximum thickness of 400 m and a minimum areal extent of 100,000 km2. The unit is unusual in that it is virtually devoid of other rock types and displays sedimentary structures that consist almost entirely of short-spaced ripple marks and parallel stratification, both formed by oscillatory flow. The ripples have spacings that are consistently small (average < 5 cm) for the entire thickness and lateral extent of the unit. Application of empirical and analytical methods yields average water depths in the range 2 cm to 2 m (maximum 5.6 m). Apparently, shallow water was maintained over a Large area for a long period of time, yet evidence of tidal and e aporitic conditions are lacking. We interpret that sedimentation was in a large, hydrographically open, tide-free, fresh-water lake, or series of lakes, that occupied a low-relief continental depression in a wet, possibly equatorial, climate where continuously high rainfall and well-developed outlets combined to prevent raised salinities.


Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24