Date of Award

Fall 12-2017

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Geography and Geology

Committee Chair

Jeremy Deans

Committee Chair Department

Geography and Geology

Committee Member 2

Frank Heitmuller

Committee Member 2 Department

Geography and Geology

Committee Member 3

Mark Puckett

Committee Member 3 Department

Geography and Geology

Abstract

Fe-Ti oxides are important components of oceanic core complexes (OCC) formed at slow-spreading mid-ocean ridges since Fe-Ti oxides are more susceptible to crystal-plastic deformation than silicate minerals. This study investigated the predicted relationship between the presence and concentration of Fe-Ti oxides and the presence and intensity of crystal-plastic deformation in gabbroic samples from Atlantis Bank, Southwest Indian Ridge (SWIR). Atlantis Bank is an oceanic core complex that formed through the exhumation of lower oceanic crust along a detachment fault. OCCs form along slow-spreading ridges and are characterized by the complex interactions between magmatism and lithospheric extension, thus making these complexes more susceptible to crystal-plastic deformation at higher temperatures. Atlantis Bank has been the focus of many scientific expeditions including: Ocean Drilling Program Holes 735B, and 1105A, International Oceanic Discovery Program Hole U1473A, and submersible studies. This study utilized samples from all three holes from near the seafloor to a depth of 1.5 km below the seafloor. This study calculated Fe-Ti oxide concentrations within the samples using the open source software package Fiji and statistically analyzed them using the open source software package R. The results indicate that Fe-Ti oxide concentration does correlate with crystal-plastic foliation (CPF) intensity, showing that 76.3% of samples with 5% or more Fe-Ti oxides have a corresponding CPF value of 2 or more (porphyroclastic foliation to ultramylonitc). These results indicate that there is a relationship between Fe-Ti oxide concentration and the CPF intensity within the samples taken from Atlantis Bank, SWIR.

ORCID ID

orcid.org/0000-0002-5163-4359

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