Document Type

Thesis

Degree Name

Master of Arts (MA)

Department

Geography & Environmental Studies

Faculty/School

Faculty of Arts

First Advisor

Houston Saunderson

Advisor Role

Thesis Supervisor

Abstract

Modern and ancient environments associated with Lakes Algoma and Huron were studied according to attributes of stratigraphy, sediment texture, parameters, sediment size distribution, bedforms, and primary sedimentary structures. Results from a computation of wave refraction diagrams and from an examination of the wave climate characteristics indicate that the modern embayment is low energy.

A sediment texture comparison between modern and ancient environments indicates that higher energy pervailed in the ancient environment relative to the present day environment. The cobble and gravel sediments as well as an extensive belt of foredunes preserved in the ancient environment are evidence of this high energy.

Sediment textural parameters of mean, standard deviation, skewness, and kurtosis were combined in bivariate plots to test their reliability for discriminating between environments. Results from four combinations of those parameters were not totally favourable. Only a plot of standard deviation versus skewness proved useful.

Component populations are useful discriminators of depositional environments. Inferred environments of beach, fluvial, and dune as well as modern lacustrine sediments could be identified by the characteristics of their component population curves. Moreover, characteristic curves that represent various subenvironments for the modern near shore zone are evident. These have been assimilated into a grain size distribution facies indicator.

Provision of a facies model for a barred-lacustrine bayhead was made possible by an examination of preserved bedforms and primary sedimentary structures. High energy bedforms of parallel laminae and massive bedding are always preserved to low energy ripple cross-laminae. The sequence of ripple cross-laminae that forms in response to increasing energy as as follows: symmetrical, assymetrical, oscillatory, and combined flow. An examination of such preserved features yields information that can be used to decipher flow directions, energy gradients, and flow characteristics within specific subenvironments.

Convocation Year

1977

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