Term of Award

Summer 2025

Degree Name

Master of Science, Applied Physical Science

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Digital Commons@Georgia Southern License

Department

Department of Chemistry and Biochemistry

Committee Chair

Sarah Friedman

Committee Member 1

Robert Vance

Committee Member 2

Jacque Kelly

Abstract

The magnetic properties of oceanic crust evolve with age due to chemical alteration, changes in magnetic mineralogy, and physical processes associated with seafloor spreading. This study investigates how magnetic properties change over time in basaltic rocks from the northern Mid Atlantic Ridge, with a focus on two V-shaped ridge sites (VSRs; U1562 and U1563), two V-shaped troughs (VSTs; U1554 and U1555) and a normal crust site formed during episodic mantle upwelling. Magnetic analyses including anisotropy of magnetic susceptibility (AMS), natural remanent magnetization (NRM), alternating field demagnetization (AF) and hysteresis loops, was performed with optical microscopy and scanning electron microscopy (SEM) imaging to assess variations in grain size, domain state, and mineralogy. Results indicate progress transformation from primary minerals (olivine, pyroxene, Iron oxide) to secondary minerals like iddingsite, sideromelane, palagonite, celadonite phases with increasing crustal age, leading to a decline in NRM intensity and Koenigsberger ratios (Q). Magnetic domain states also shift from multi-domain to pseudo-single domain characteristics, with variations linked to microstructural and mineralogical changes. These findings enhance understanding of crustal magnetization processes and have implications for interpreting marine magnetic anomalies and the geodynamic evolution of mid-ocean ridges.

OCLC Number

1531379962

Research Data and Supplementary Material

Yes

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