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Tectonics and Structure

City University of New York (CUNY)

Dissertations and Theses

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Full-Text Articles in Geology

Pressure, Temperature, And Stress Conditions Of Southern Alpine Fault (New Zealand) Mylonites, Jake T. Reitman Jan 2019

Pressure, Temperature, And Stress Conditions Of Southern Alpine Fault (New Zealand) Mylonites, Jake T. Reitman

Dissertations and Theses

The Alpine Fault, New Zealand, provides a unique window into the rheologic history of a seismically-active continental plate boundary. Due to lower exhumation rates along southern portions of the fault relative to the well-studied central Alpine Fault, deformation ages vary along strike by ~15 m.y.. Mylonites collected from two southern creeks near Haast, NZ, display a uniform recrystallized grain size of ~11 𝜇m in mylonitic quartz indicating differential stress values in the south of ~100 MPa, roughly twice the stress values observed in the central Alpine Fault. Constraints from Ti-in-quartz thermobarometry and Raman Spectroscopy of Carbonaceous Material (RSCM) indicate mylonitization …


Mechanisms Of Shear Zone Localization And Raman Thermobarometry In Spinel Peridotites From The Alpine Fault, New Zealand, Emily J. Lubicich Jan 2017

Mechanisms Of Shear Zone Localization And Raman Thermobarometry In Spinel Peridotites From The Alpine Fault, New Zealand, Emily J. Lubicich

Dissertations and Theses

A suite of xenoliths from two localities on South Island, New Zealand, exhibit rare microstructures and provide information on deformation during the early stages of development of the Alpine Fault. The first set of samples has evidence of dislocation creep with subgrains, recrystallized grains, undulose extinction and a lattice preferred orientation. These samples also show evidence of post deformation static grain growth with polygonal grains, 120° triple junctions, and euhedral grains within larger grains of the same phase. Samples from the second locality also show evidence of dislocation creep but with minimal static grain growth. This set also has a …