Microstructural study of natural fractures in Cape Roberts Project 3 core, Western Ross Sea, Antarctica

C. Millan; T. Wilson; T. Paulsen

doi:10.3133/ofr20071047srp053

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Microstructural study of natural fractures in Cape Roberts Project 3 core, Western Ross Sea, Antarctica

C. Millan·T. Wilson·T. Paulsen

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Abstract

Microstructures in natural fractures in core recovered offshore from Cape Roberts, Ross Sea, Antarctica, provide new constraints on the relative timing of faulting and sedimentation in the Victoria Land Basin along the Transantarctic Mountain rift flank. This study characterizes the textures, fabrics and grain-scale structures from thin section analysis of samples of microfaults, veins, and clastic dikes. Microfaults are abundant and display two different types of textures, interpreted to record two different deformation modes: pre-lithification shearing and brittle faulting of cohesive sediment. Both clastic dikes and calcite veins commonly follow fault planes, indicating that injections of liquefied sediment and circulating fluids used pre-existing faults as conduits. The close association of clastic injections, diagenetic mineralization, and faulting indicates that faulting was synchronous with deposition in the rift basin

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Source-reported bounding extent: -79.3° to -76.9° latitude; -165.07° to -157.42° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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C. Millan, T. Wilson, T. Paulsen. 2007. Microstructural study of natural fractures in Cape Roberts Project 3 core, Western Ross Sea, Antarctica. https://doi.org/10.3133/ofr20071047srp053

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