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Geology of the Alston District Houghton and Baraga Counties, Michigan

Citation

Roberts, Ellis Earl (1940) Geology of the Alston District Houghton and Baraga Counties, Michigan. Master's thesis, California Institute of Technology. doi:10.7907/YB0S-SR57. https://resolver.caltech.edu/CaltechETD:etd-04032009-144817

Abstract

The copper-bearing sediments and flows of Keweena age which underlie the northwest side of Keweenaw Point form a conformable series which to the southeast has been thrust over the Cambrian Jacobsville sandstone. The stratigraphic correlation of the Freda sandstone, which lies at the top of the copper-bearing series, to the Jacobsvilie sandstone is uncertain, as are also the definite dating of the periods of deformation and the age of the copper mineralization. Field work was conducted to the southeast of the main copper-bearing area with the hope of establishing: (1) the date of the native copper mineralization, (2) the relations of the Freda and Jacobsville sandstones, and (3) the dates of deformation. The existence of a pre-Jacobsville period of mineralization was established, but its correlation with the native copper mineralization to the northwest cannot be definitely established. The Jacobsville sandstone rests unconformably upon Keweenawan flows; in an adjacent area, the Freda sandstone rests conformably on flows of the same character. Hence the Jacobsville sandstone is thought to be later than and unconformable to the Freda sandstone. At one locality the Keweenann flows are tilted and sheared, while the overlying Jacobsville sandstone is not affected, thus proving the existence of a pre-Jacobsville but post-Keweenawan deformation. Elsewhere, the marked disturbances of Lower Paleozoic strata prove another period of deformation which is definitely later than the Silurian, and probably later than the Devonian.

Item Type:Thesis (Master's thesis)
Subject Keywords:(Geology) ; Keweenaw Point, Keweenaw Fault, Sturgeon River, Sturgeon Falls, Jacobsville Sandstone
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.
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 April 1940
Additional Information:Supplemental Files Information: Geologic map of the Alston District: Supplement 1 from "Geology of the Alston district Houghton and Baraga Counties, Michigan" (Thesis). Date(s) Collected: 1940. Geologic and topographic map of Silver Mountain: Supplement 2 from "Geology of the Alston district Houghton and Baraga Counties, Michigan" (Thesis). Date(s) Collected: 1940. Geologic and topographic map of the Sturgeon Falls: Supplement 3 from "Geology of the Alston district Houghton and Baraga Counties, Michigan" (Thesis). Date(s) Collected: 1940. Geologic and topographic map of Sherman Hill: Supplement 4 from "Geology of the Alston district Houghton and Baraga Counties, Michigan" (Thesis). Date(s) Collected: 1940. Geologic and topographic map of Limestone Mountain: Supplement 5 from "Geology of the Alston district Houghton and Baraga Counties, Michigan" (Thesis). Date(s) Collected: 1940. Map of Silver Mountain adit: Supplement 6 from "Geology of the Alston district Houghton and Baraga Counties, Michigan" (Thesis). Date(s) Collected: 1940.
Record Number:CaltechETD:etd-04032009-144817
Persistent URL:https://resolver.caltech.edu/CaltechETD:etd-04032009-144817
DOI:10.7907/YB0S-SR57
Related URLs:
URLURL TypeDescription
https://doi.org/10.22002/D1.806DOISupplement 1 in CaltechDATA: Geologic map of the Alston District
https://doi.org/10.22002/D1.807DOISupplement 2 in CaltechDATA: Geologic and topographic map of Silver Mountain
https://doi.org/10.22002/D1.808DOISupplement 3 in CaltechDATA: Geologic and topographic map of the Sturgeon Falls
https://doi.org/10.22002/D1.809DOISupplement 4 in CaltechDATA: Geologic and topographic map of Sherman Hill
https://doi.org/10.22002/D1.810DOISupplement 5 in CaltechDATA: Geologic and topographic map of Limestone Mountain
https://doi.org/10.22002/D1.811DOISupplement 6 in CaltechDATA: Map of Silver Mountain adit
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1264
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:07 Apr 2009
Last Modified:17 Aug 2023 00:17

Thesis Files

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PDF (Roberts_e_1940.pdf) - Final Version
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5MB
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PDF (Geologic map of the Alston District) - Supplemental Material
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7MB
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PDF (Geologic and topographic map of Silver Mountain) - Supplemental Material
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7MB
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PDF (Geologic and topographic map of the Sturgeon Falls) - Supplemental Material
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18MB
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PDF (Geologic and topographic map of Sherman Hill) - Supplemental Material
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445kB
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PDF (Geologic and topographic map of Limestone Mountain) - Supplemental Material
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11MB
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PDF (Map of Silver Mountain adit) - Supplemental Material
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6MB

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