About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

Journal of Sedimentary Research (SEPM)


Journal of Sedimentary Petrology
Vol. 46 (1976)No. 4. (December), Pages 761-769

Paleocurrent Analysis of Large-Scale Cross-stratification in the Brampton Esker, Ontario

Houston C. Saunderson


Paleocurrent analysis of trough-shaped cosets of cross-bedding in the Brampton esker indicated a high flow variability during deposition. Within-site (w) and between-site (^Bgr) estimates of the sampling distribution precision parameter (ksd) equalled 1.1317 and 6.4218 respectively, giving ksd = 36.7647. The semi-angle of confidence (^psgr) about the grand vector resultant was 24° at ^agr = 0.01. As shown by the higher precision of ^Bgr, future sampling in the esker would be increased in efficiency by using more sites than by increasing the number o observations at each site.

Bartlett's test for homogeneity-of-variance showed that the large-scale cross-strata of this report had a significantly larger within-site variance than small-scale cross-laminae of an earlier report at ^agr = 0.05 and 0.01.

Preliminary results suggested that dunes may be more efficient estimators of the overall average flow direction than ripples in the esker, but further rigorous testing is required concerning this point. Analysis-of-variance of paleocurrent vectors demonstrated that the rank of ripple and dune structures as estimators of the grand vector resultant could not be based solely on w because (1) ^Bgr was statistically significant at ^agr = 0.01 and (2) the ripple and dune structures did not come from the same site.

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