Abstract

The Neoproterozoic Kingston Peak Formation (KPF) is known for its diamictites interpreted as of glacial origin. The KPF overlies the Beck Spring Dolomite (BSD) that contains microfossils and microbialites. This study aims to test correlation between outcrops and understand the abrupt change from BSD to KPF. It focuses on the basal 4 meters of the KP1 subunit of the KPF as it appears in the Beck Canyon region, Kingston Range, California. We describe and correlate sedimentary rocks at and immediately overlying the contact and analyze the sedimentary structures, textures and sequences. We have found only three sites in the northern Kingston Peak Range where the contact can be observed. At each site we measured sections about 4 meters long across the contact. The top of the BSD in all locations contains microbial laminations, oncoids, pisoids, sheets of chert and peloids. Thin sections from about 15 cm below the contact to about 50 cm above the contact show microbial laminations with some peloids or ghosts of peloids and abundant chert. The base of the KPF is composed of millimeter to centimeter-scale alternating two bed types named A-bed and B-bed. A-beds are clastic-rich and B-beds are dolomite-rich. A-beds are dolomitic silty mudstones with abundant muscovite. B-beds are recrystallized silty dolostones with peloid ghosts. A few of the

beds show faint current ripple cross bedding, cross bedding and lenticular structures. A to B bed contacts are sharp. At all stratigraphic levels, clastics have immature textures and compositions. XRD and thin section analysis show a trend of decreasing dolomite up-section. Measurement and analysis of individual alternating bed thickness show cyclical patterns and a gradational increase in bed thickness to massive sandstones. Mineralogical patterns, pisoid-rich layers, and bed thickness patterns can all be correlated among the three sections. The pattern of increasing clastic content and bed thickness upsection suggests clastic influx during progradation that progressively overwhelmed carbonate production. This progradational setting could have occurred on a tide dominated delta or on a prograding tidal flat. The BSD-KPF contact at Kingston Range most likely represent a sequence boundary as evidenced by a change in lithology from dolostones to clastics.

LLU Discipline

Geology

Department

Basic Sciences

School

School of Medicine

First Advisor

Nick, Kevin E.

Second Advisor

Awramik, Stanley

Third Advisor

Buchheim, H. Paul

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2016

Date (Title Page)

6-2016

Language

English

Library of Congress/MESH Subject Headings

Sedimentology; Geology - Stratigraphic-- Neoproterozoic;

Subject - Local

Neoproterozoic formations; Kingston Peak Formation; Beck Spring Dolomite; Sedimentary Structures

Type

Thesis

Page Count

91

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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