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Geology of part of the Adelanto Hills. Report on the Geology of the Puente Hills


Haffner, Bernhard K. (1940) Geology of part of the Adelanto Hills. Report on the Geology of the Puente Hills. Bachelor's thesis, California Institute of Technology.


The Adelanto Hills are a low range of folded limestone, situated about five miles northwest of Adelanto, California. The limestone is a dark blue finely crystalline, roughly bedded type, which has been hydrothermally altered in places to a white crystalline limestone, or to a fine grained highly altered brown limestone. The main igneous rock outcrops in the south part of the area and is a light colored, coarse grained granodiorite body that apparently has been faulted into place. A complimentary association of several fine grained, dark colored granodiorite intrusions and numerous pegmatite dikes occurs in the northern part of the area. Several large light colored acidic dikes intrude the limestone and their relationships to the other igneous rocks cannot be determined, with the exception that they are earlier than the pegmatite. The alteration of the blue limestone to the white limestone is due in part to the cutting of the area by the acid dikes. Hydrothermal solutions controlled to some extent by igneous contacts, the bedding of the blue limestone and possibly by faults, are responsible for the rest of the alteration. The area is cut by a large fault trending N65W and by numerous smaller faults trending about N2OW. The structure on either side of the main fault is roughly parallel. The mineralization of the area is mainly a contact metamorphic type, the ore minerals being lead, zinc and silver. Oxidation has resulted in some secondary enrichment, especially of silver. Some scheelite is mined at the present time from a contact zone between porphyry and limestone.

Item Type:Thesis (Bachelor'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):
  • Unknown, Unknown
Thesis Committee:
  • Unknown, Unknown
Defense Date:3 June 1940
Additional Information:Submitted June 3, 19040. Field party: D. Wasem, H.Reynolds, B. Haffner. Report on the Geology of the Puente Hills pages [12-20]
Record Number:CaltechTHESIS:12222009-152143529
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5477
Deposited By: Tony Diaz
Deposited On:14 Jan 2010 18:15
Last Modified:12 Nov 2016 00:41

Thesis Files

PDF (Full thesis) - Final Version
See Usage Policy.

PDF (Geologic map of part of Adelanto Hills) - Supplemental Material
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