A Petrographic Study of Pressure Solution Cleavage in Metagreywackes of the Goldenville Formation, Meguma Group, Nova Scotia

Abstract

<p> Metagreywackes of the Goldenville Formation, Nova Scotia, possess a well developed spaced cleavage. Petrographic evidence suggests that the dominant mechanism producing this cleavage has been pressure solution, involving the dissolution of quartz from cleavage zones. A large amount of shortening occurs during cleavage development due to this volume loss of quartz. Based on a simple comparison of amounts of mica in cleavage and lithon zones shortenings of 50 - 60% have been found.</p> <p> Cleavage zones are marked by distinct mineralogical variations, notably a high content of white mica, and a low quartz content. Trends for all components have been documented to characterize the cleavage and lithon zones.</p>