Geology of the Sumdum Copper-Zinc Prospect, Southeastern Alaska (open access)

Geology of the Sumdum Copper-Zinc Prospect, Southeastern Alaska

From abstract: The Sumdum copper-zinc prospect is in an alpine region on the mainland of southeastern Alaska, about 50 miles southeast of Juneau and about 25 miles west of the Canadian boundary. The ore-bearing outcrops at the prospect were discovered by the Alaska Helicopter Syndicate during the summer of 1958. The prospect is within a few thousand feet of the western margin of the . Coast Range batholith in regionally metamorphosed rocks that locally -have -been contact: metamorphosed. Most of the known ore deposits are -in the intermediate unit of three metamorphic-rock units that were mapped.
Date: 1964
Creator: MacKevett, E. M., Jr. & Blake, M. Clark, Jr.
System: The UNT Digital Library
Geology of the North Bradfield River Iron Prospect, Southeastern Alaska (open access)

Geology of the North Bradfield River Iron Prospect, Southeastern Alaska

From abstract: The North Bradfield River iron prospect is in southeastern Alaska in rugged terrain about 8 miles southwest of the Canadian boundary and about 15 miles northeast of the head of Bradfield Canal. The prospect includes several magnetite-rich ore bodies of pyrometasomatic origin that are localized in skarn. The skarn forms a small part of a northwestward-trending roof pendant that is enclosed in the composite Coast Range batholith. The dominant rocks of the roof pendant are gneiss, granulite, schist, and marble. The ore, which consists almost entirely of magnetite, contains subordinate amounts of hematite, hydrous iron sesquioxides, pyrrhotite, chalcopyrite, and malachite. The ore bodies are crudely stratiform and apparently discontinuous. The largest ore body exposed is traceable for about 350 feet along its strike and averages about 25 feet in thickness. An accurate appraisal of the economic potential of the prospect was precluded by poor outcrops, local snow cover, and inadequate subsurface data.
Date: 1963
Creator: MacKevett, E. M., Jr. & Blake, M. Clark, Jr.
System: The UNT Digital Library
Geology of Part of the Craig C-2 Quadrangle and Adjoining Areas, Prince of Wales Island, Southeastern Alaska (open access)

Geology of Part of the Craig C-2 Quadrangle and Adjoining Areas, Prince of Wales Island, Southeastern Alaska

From abstract: The area mapped is on the east coast of Prince of Wales Island, southeastern Alaska, about 35 miles northwest of the town of Ketchikan. Deposits of magnetite and copper in the mapped area and on Kasaan Peninsula, which adjoins it on the southeast, have been mined for copper and have produced more than 600,000 tons of ore valued at more than $6 million.
Date: 1961
Creator: Sainsbury, C. L.
System: The UNT Digital Library
Geology of the Craig Quadrangle, Alaska (open access)

Geology of the Craig Quadrangle, Alaska

From abstract: The Craig quadrangle, in southeastern Alaska, lies entirely within the Tongass National Forest and includes a large part of Prince of Wales Island, the largest island of the Alexander Archipelago. Sedimentary, volcanic, and metamorphic rocks of Paleozoic and Mesozoic age are exposed as complexly folded and faulted sequences. Paleozoic rocks occupy a broad geanticlinal area comprising Prince of Wales Island and the islands to the west. Metamorphosed Mesozoic rocks form a geosynclinal area along and east of Clarence Strait. Granitic and dioritic stocks and masses, mainly of Mesozoic age, intrude the Paleozoic and Mesozoic rocks. Remnants of volcanic rocks of Tertiary age exist on Suemez Island, and scattered areas of Tertiary clastic rocks and volcanic rocks are exposed near Clarence Strait. Deposits of Quaternary age are mainly thin glacial deposits and narrow bands of stream alluvium.
Date: 1961
Creator: Condon, W. H.
System: The UNT Digital Library
Geology of the Mount McKinley Quadrangle, Alaska (open access)

Geology of the Mount McKinley Quadrangle, Alaska

From abstract: The Mount McKinley quadrangle, in south-central Alaska, includes parts of the Alaska Range, the Tanana and Kuskokwim lowlands, and the Kuskokwim Mountains. Schists of Precambrian age crop out in the northern foothills of the Alaska Range. Sedimentary and volcanic rocks of Paleozoic and Mesozoic age are exposed in the Kuskokwim Mountains, where little is known of their distribution and character, and in the Alaska Range, where they occupy the axial part and northern limb of a great synclinorium. Granitic batholiths, largely of Mesozoic age, intrude the Paleozoic and Mesozoic rocks in the Alaska Range.
Date: 1961
Creator: Reed, John Calvin, Jr.
System: The UNT Digital Library
Tofty Tin belt, Manley Hot Springs District, Alaska (open access)

Tofty Tin belt, Manley Hot Springs District, Alaska

From abstract: Buried placer deposits in a belt about 8 miles long by 1 mile wide at Tofty, near Manley Hot Springs, Alaska, have yielded a few hundred tons of cassiterite as a byproduct to the recovery of several million dollars in placer gold.
Date: 1961
Creator: Wayland, Russell Gibson
System: The UNT Digital Library