Masters Theses

Author

Avikant Dayma

Abstract

"For decades, numerous studies have been conducted and contradictory results were achieved about the origin and evolution of the Yellowstone supervolcano and the Eastern Snake River Plain. Whether the 640 km long time-progressive chain of rhyolitic calderas was formed due to mantle-plume or a result of lithospheric extension allowing the emergence of melt on the surface is still a debate. Using receiver function analyses, this study determines the crustal thickness and the Vp/Vs ratio below the Yellowstone Plateau, Wyoming Province (WP), Idaho Batholith (IB), Eastern Snake River Plain (ESRP), and the northern Basin and Range Province (BRP). The thickness is highest below the Wyoming Province (46 to 54 km) and reduces to as low as 30 km towards the east in the Batholith Province. The Yellowstone Caldera sits above the Moho not deeper than 44 km and the entire extension of the Eastern Snake River Plain varies in Moho depth from 44 km below the Island Park Caldera, 40 km below the Heise Caldera and shallows up to 37 km below the Picabo and Twin Fall Calderas. The thickness of the crust below ESRP does not show a noticeable variation from the BRP lying to the south and north of it. The receiver functions below the Yellowstone Plateau show a low-velocity zone at a shallow depth probably signifying the presence of a shallow magma chamber. Compressional velocity variations in the mantle show low-velocity anomaly of -9% till the depth of 280 km NW of the Yellowstone Plateau and a high-velocity region beneath it starting from 320 km. This study acknowledges both the controversial theories proposed for the explanation of the magmatic volcanic calderas"--Abstract, page iii.

Advisor(s)

Gao, Stephen S.

Committee Member(s)

Gao, Stephen S.
Liu, Kelly H.
Ge, Mao Chen

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology and Geophysics

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2017

Pagination

vii, 74 pages

Note about bibliography

Includes bibliographic references (pages 65-73).

Geographic Coverage

Wyoming
Idaho

Time Period

Precambrian

Rights

© 2017 Avikant Dayma, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 11162

Electronic OCLC #

1003050382

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