Dehlinger, Peter (1943) A magnetic survey of Sand Canyon for placer deposits, San Gabriel, California. Master's thesis, California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:03052010-085246594
A magnetic survey was made in Sand Canyon, which is in the northwestern part of the an Gabriel Mountains, the object being to locate possible placer deposits. The bedrock in this area is an iron rich igneous rock which has been intruded by numerous dikes. The stream gravels consist of large boulders interspersed with highly magnetic sands. Over 200 stations were involved in the survey in which vertical magnetic intensity was measured using a Schmidt-type vertical magnetometer. Magnetic anomalies found were so large that all instrument corrections were ignored. Results of the survey show that the magnetic intensity readings are due to both the basement and the gravels, though the gravels have a greater effect. The location of the largest anomalies, thus the most probable placers, is at the eastern end of the area. Downstream from this site the intensity decreases rather uniformly; upstream it decreases very sharply where the canyon narrows suddenly. Geologically, this is the expected picture. It is thought that a fault has been located, which strikes up the canyon, but this has not been confirmed by surface evidence. Data and profiles of the traverses, and a detailed map of the magnetic intensities of the region are included in this paper.
|Item Type:||Thesis (Master's thesis)|
|Degree Grantor:||California Institute of Technology|
|Division:||Geological and Planetary Sciences|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||1 June 1943|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||12 Apr 2010 18:47|
|Last Modified:||26 Dec 2012 03:22|
- Final Version
See Usage Policy.
- Supplemental Material
See Usage Policy.
Repository Staff Only: item control page