CGRG Bibliography of Canadian Geomorphology
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Author : Emory-Moore, M.L.
Date : 1993
Title : Marine placer formation on glaciated coastlines: deposit types, assessment criteria and site investigations in Newfoundland And Labrador
Publication : Unpublished Ph.D. dissertation. University of Mississippi
Issue :
Page(s) :
Abstract
The marine placer potential of Newfoundland and Labrador, an area of eastern Canada that has been extensively glaciated, is examined. A classification scheme for marine placer deposits on glaciated coastlines is developed using as classifiers the parameters source (primary or secondary), mode of mineral concentration (allochthonous or autochthonous) and depositional environment (beach or nearshore). Formational constraints related to sediment supply, wave energy and relative sea level fluctuations are examined for each deposit type and used as a rule base in the development of a computer-based methodology for regional placer assessment. The assessment technique is applied to Newfoundland and Labrador and three sites are chosen for detailed field investigations. A large volume, low grade deposit of chromitiferous sand is delineated in Port au Port Bay, western Newfoundland. Raised marine sediment facies in the Lake Melville area of eastern Labrador are examined for their magnetite/ilmenite placer potential; the highest grade occurrences were found in raised and modern beach sediments on the Porcupine Strand. Deposit models depicting the paloenvironmental evolution of the placer occurrences are developed for each site. Several sites containing particulate gold are identified along the northern Newfoundland coast. More work is required to determine their economic viability. In general, the marine placer potential of Newfoundland and Labrador is deemed modest. Glaciation has served to both enhance and detract from marine placer formation in Newfoundland and Labrador. Adverse effects of glaciated coastal settings are particularly evident in allochthonous placer formation and include: a storm dominated coastline; a highly irregular coastal morphology; rapid fluctuations of sea level; and the textural and chemical immaturity of glacigenic sediment. In contrast, autochthonous placer formation has been greatly enhanced by glaciation. The most advantageous effect of glaciation has been the provision of ample, low grade auriferous sediment to the coastal environment.
Bibliography of Canadian Geomorphology