Department of Geology, University of Otago, MSc

Frio Shear Zone: a major tectonic boundary in south Victoria Land

The basement rocks of south Victoria land consist of sedimentary rocks intruded by igneous rocks which have been variably metamorphosed and deformed, such that many of their original sedimentary features are now obscured making it extremely difficult to investigate their origin. As a result, previous work in this area has assumed that all the sedimentary rocks were originally part of the same sedimentary pile and termed this sequence of sediments the Skelton Group. Recent work has shown significant differences within this group and divided it into structural blocks. The nature of the boundary between these block is unknown as the boundaries lie mostly under glacier ice. The only known outcrop of these structural boundaries is at Frio Point and was called the Frio Shear Zone. The main aim of this project was to examine the Frio Shear Zone petrographically and structurally, and to document the extent of the differences across the shear zone to determine minimum estimates of relative movement.

Publications

Beckett, S. A. The Frio Peak area, upper Walcott Glacier region, southern Victoria Land, Antarctica: a detailed study of rocks comprising Frio Shear Zone. MSc, University of Otago, 2003.