Stephen C. Delahay

B. Sc. Honours Thesis

Metamorphism of the George River Group; Gold Brooks, Victoria County, Cape Breton Island, Nova Scotia.

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The Precambrian George River Group of Cape Breton Island, Nova Scotia is characterized by metasediments and metavolcanic rock types.

A sequence of predominantly feldspathic quartzites slates and quartzites at Gold Brooks has been deposited in an offshore environment. During deposition, recurrent mafic tuffs and lavas have interrupted the sequence producing thin interbeds of mafic and felsic material with occasionally more massive units of these types.

Burial was followed by granitic intrusion during the Cambrian. The sequence has undergone at least one period of regional metamorphism, this being the Acadian orogeny. The regional metamorphic grade in the study area is observed to increase to the NNW from upper greenschist to middle amphibolite facies.

The intrusion of gold-bearing quartz veins in one location within the section has produced a wall-rock alteration which extends approximately 5 cm from the vein.

A zone of middle greenschist facies metasediments occurs anomalously in Second Gold Brook, apparently associated with the mineralization, though no mechanism for this apparent retrograde metamorphism has been recognized.

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Pages: 106
Supervisor: D. B. Clarke