Electronic Theses and Dissertations

Identifier

2441

Date

2015

Document Type

Thesis

Degree Name

Master of Science

Major

Earth Sciences

Concentration

Geophysics

Committee Chair

Eunseo Choi

Committee Member

Christine Powell

Committee Member

Jer-Ming Chiu

Abstract

Bathymetry reveals diverse morphologies at Mid-ocean Ridges (MORs). Previous studies show that the morphologies at slow spreading MORs are mainly controlled by the ratio (M) between rates of magma supply and plate extension. 2D models successfully explain many cross-sectional observations across the ridge axis. However, magma supply varies along the ridge and the interaction processes between the tectonics and magmatism at MORs are inevitably three dimensional. We investigate the consequences of this along-axis variations in diking in terms of faulting patterns and the associated structures using a 3D parallel geodynamic modeling code, SNAC. Many observed structural features are reproduced. We also propose asynchronous faulting induced tensile failure as a new possibility for explaining corrugations. Average M = 0.6425 is suggested as a boundary value for separating abyssal hills and oceanic core complexes (OCCs) formation. Previous inconsistency for OCCs formation between 2D model results (M = 0.3∼0.5) and field observations (M < 0.3 or M > 0.5) is reconciled by our 3D along-ridge coupling argument.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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