Late Ross-orogenic deformation of basement rocks in the northern Deep Freeze Range, Victoria Land, Antarctica; the Lichen Hills shear zone

• Main Authors: Läufer, Andreas L., Fisker, Frank, Phillips, Glen
• Other Authors: The University of Newcastle. Faculty of Science & Information Technology, School of Environmental and Life Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: Deutsche Gesellschaft fuer Polarforschung e.V. 2011
• Subjects: Antarctica; Lichen Hills Shear Zone; Ross Orogen; Wilson Mobile Belt; shear zones; basement rocks; Deep Freeze Range; Granite Harbour; Lichen Hills; Oates Land; Rennick; Rennick Glacier; Victoria Land; Antarc*; Polarforschung
• Online Access: http://hdl.handle.net/1959.13/1061540

Kinematic data from the basement rocks exposed at Lichen Hills in the upper Rennick Glacier, northern Victoria Land, indicate the presence of an intra-Wilson Terrane late Ross-orogenic high-strain reverse shear zone. ENE directed ductile shearing and WSW-directed late-stage brittle reverse faults overprint metasedimentary rocks and thick leucogranites of the Granite Harbour Intrusives. The Ross-orogenic age of the structures is attested by the involvement of leucogranites in ductile shearing and cross-cutting relationships between younger aplitic dykes and brittle deformations. This structural pattern strongly supports a relationship between the Lichen Hills Shear zone and the Wilson Thrust in Oates Land, the eastern branch of a late-Ross bivergent high-strain thrust system. Post-Ross structures are represented by reverse off-sets of the – in this area – Triassic to early Jurassic Beacon strata that are probably related to volcanotectonic events during Ferrar intrusion and the Cenozoic development of NW-SE striking dextral faults and N-S striking large-scale normal faults that parallel the Rennick Glacier.