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Geology of the Sugar Pine area, Madera County, California


Greenwood, Robert (1943) Geology of the Sugar Pine area, Madera County, California. Master's thesis, California Institute of Technology.


The Sugar Pine area includes nine square miles in northern Madera County, on the western slope of the Sierra Nevada. Intrusive rocks of the Sierra batholith surround a central roof pendant and associated minor bodies of strongly folded and metamorphosed Paleozoic sediments. The main mass of the intrusive is tonalite, petrogaphically notable for the selective albitization of its potash feldspar. It contains an abundance of diorite and gabbro and many small pegmatite and aplite dikes complete the Jurassic intrusive sequence. The metamorphic rocks are mainly quartzite, with some schist and calcareous beds, the last giving rise to three distinct metamorphic rock types. The margin of the pendant is locally marked by a zone of partial assimilation and reconstitution. Post-Jurrasic fracturing, perhaps involving some displacement, serves as structural control for several springs in the area. Tungsten mineralization is associated with one of two large pegmatites intruding the central pendant. Scheelite occurs disseminated in lenses of tactite, a restricted facies of the metamorphosed calcareous beds. Some tactite lenses carry over one per cent of scheelite, but small total volume of ore makes the exploitation of the deposit impractical.

Item Type:Thesis (Master's thesis)
Subject Keywords:Geology
Degree Grantor:California Institute of Technology
Division:Geological and Planetary Sciences
Major Option:Geology
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Fraser, Horace J. (advisor)
  • Campbell, Ian (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:April 1943
Record Number:CaltechTHESIS:03312010-140105733
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5665
Deposited By: Tony Diaz
Deposited On:16 Apr 2010 19:07
Last Modified:30 Nov 2016 23:56

Thesis Files

PDF - Final Version
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PDF (Geologic map) - Supplemental Material
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PDF (Geologic map of Tin Bucket tungsten claims) - Supplemental Material
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