Timing of deformation and the mechanism of cleavage development in a Newfoundland melange ( Canada).

Abstract

This paper is concerned with two aspects of folding and cleavage development in the 'Carmanville Ophiolitic Melange' of Newfoundland. First it is concerned with the problem of the timing of deformation relative to lithification and metamorphism, and second it is concerned with development of the cleavage. The clearage is a second generation axial-plane structure and microstructural observations, presented here, show it to be later than the peak of metamorphism. The second generation structures are a product of hard-rock deformation. The origin of the F1 folds however, remains equivocal. Dyke-like structures previously attributed to migration of thixotropic melange units are also post lithification and are a product of faulting and metamorphic differentiation. The S2 cleavage is largely a product of rotation. -from Author