عنوان

A Late Pleistocene Record of Highstand Shedding and Dust Flux from the Inner Sea of the Maldives: Site U1467, Iodp 359

Number

TL52559

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

A Late Pleistocene Record of Highstand Shedding and Dust Flux from the Inner Sea of the Maldives: Site U1467, Iodp 359

General Material Designation

[Thesis]

First Statement of Responsibility

Mohammadi, Obeyd

Subsequent Statement of Responsibility

Guo, Junhua

Name of Publisher, Distributor, etc.

California State University, Bakersfield

Date of Publication, Distribution, etc.

2020

Text of Note

109 p.

Dissertation or thesis details and type of degree

M.S.

Body granting the degree

California State University, Bakersfield

Text preceding or following the note

2020

Text of Note

The Inner Sea of the Maldives is an isolated basin in the Indo-Pacific with significant archival potential for climate-driven sedimentation. In this study, high-resolution bulk sediment data of drift deposits from basinal Site U1467B of Expedition 359 of the International Ocean Discovery Program were profiled via powder X-ray diffraction and energy dispersive X-ray fluorescence methods for their mineralogical composition and isotopic characteristics. Time-frequency analysis of the machine-derived results (241 samples) reveal an orbitally-paced cyclical character to the relative abundance of strontinum-enriched aragonite and aluminium-normalised terrestrial proxies over a core encompassing the past 2 ma (<80 mbsf). Preserved peak intensity oscillations between high points in shallow-water carbonate components (aragonite and strontium) and background pelagic rain (low-magnesian calcite) are in turn a mineralogical reflection of sea-level driven modal changes to the available accommodation space at the locus of carbonate precipitation: the carbonate platform top and slope. The variability expressed within the interpreted terrestrial molar ratios (E/Al) appears to correspond to the rise and fall of regional-scale continental aridity (India and Asia) and winter wind vigour (South Asian monsoon). As in the Arabian Sea, both local carbonate variability and regional dust flux exhibit the mode switch characteristic of the mid Pleistocene Revolution. Taken together, these signals construct the necessary context through which the varied and mixed carbonate-siliciclastic development history of the Maldives can be grasped in simple relative terms and in turn subsumed within an insolation-driven inflow model with corresponding implications for the broader history of the Western Indo-Pacific realm.

Subject Term

Geochemistry

Subject Term

Paleoclimate science

Subject Term

Sedimentary geology

Mohammadi, Obeyd

Guo, Junhua

California State University, Bakersfield

Electronic name

p

[Thesis]

276903

a

Y