Skip to Main Content
Book Chapter

Nature of Esker Sedimentation

By
Indranil Banerjee
Indranil Banerjee
Geological Survey of Canada, Ottawa, Ontario, KIA DE8, Canada
Search for other works by this author on:
;
Barrie C. McDonald
Barrie C. McDonald
Geological Survey of Canada, Ottawa, Ontario, KIA DE8, Canada
Search for other works by this author on:
Published:
January 01, 1975

Abstract

Broad questions of esker sedimentation are reviewed in this paper. Two main environmental factors, nature of the conduit through which the esker stream flowed, and site of deposition, control esker sedimentation and commonly can be determined from the sedimentary succession. Interaction of these two factors permits definition of three different models of esker sedimentation: open-channel, tunnel and deltaic. Morphology of the esker ridge, sedimentary structures, facies relationships and paleocurrent variability are important parameters of proposed sedimentation models. The models are discussed on the basis of field data from eskers at Peterborough, Ontario and at Windsor, Quebec.

Sediments of the Peterborough esker were deposited largely in an open channel bordered laterally by ice walls. Backset beds related to antidunes are preserved at places. A common environment was deltaic, where dunes and ripples delivered sediment to avalanche faces; progressively downstream from the large foresets were regressive, sinusoidal, and progressive ripples, respectively. These in turn pass into graded beds and then into lacustrine rhythmites.

Tunnel sedimentation is illustrated by sediments in single steep-sided ridges in the Windsor esker. Sheetlike cross-bedded and parallel-bedded gravel and sand units persist downstream without facies change and are arranged in vertically stacked cycles that may be annual. Flow depth in the tunnel was 1 to 4 m and accumulation of sediment was accommodated by a melting upward of the ice roof.

Deltaic sedimentation is illustrated by beads in the Windsor esker that were deposited annually as subaqueous fans in the water body at the mouth of the subglacial tunnel. Cobble and pebble gravel at the proximal end of the bead intertongues over a few meters in a downstream direction with ripple-laminated fine sand, units of “structureless'' fine and medium sand, and graded beds.

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Special Publication

Glaciofluvial and Glaciolacustrine Sedimentation

Alan V. Jopling
Alan V. Jopling
Search for other works by this author on:
;
Barrie C. McDonald
Barrie C. McDonald
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
23
ISBN electronic:
9781565761537
Publication date:
January 01, 1975

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal