Isotopic ages from intrusive rocks near the Stuyahok gold placer deposits, south-central Holy Cross quadrangle, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

Professional Paper 1615
By: , and 

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Abstract

In the Stuyahok area of the south-central Holy Cross quadrangle, Alaska, felsic to intermediate dikes and sills intrude Lower Cretaceous volcanic and volcaniclastic rocks of the Koyukuk terrane. These previously undated intrusions are the probable source of at least 933 kg (30,000 oz) of past placer gold production. Additional placer, and perhaps lode, resources are likely present at Stuyahok. New U/Pb and 40Ar/39Ar isotopic data indicate two of the dikes are early Tertiary in age (63.6+0.2 Ma and 60.4+1.1 Ma, respectively). In addition to helping constrain the age of gold mineralization, these early Tertiary ages suggest the Stuyahok dikes are part of a Late Cretaceous and early Tertiary belt of gold mineralized felsic dikes that lie in the Kuskokwim mineral belt. Also reported herein are previously unpublished conventional K-Ar ages of 69.4+2.1 Ma and 69.3+2.1 Ma for two felsic intrusions from the western edge of this mineralized belt, the Marshall–Kako Creek area, which lies about 40 km west-southwest of the Stuyahok area.

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Isotopic ages from intrusive rocks near the Stuyahok gold placer deposits, south-central Holy Cross quadrangle, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998
Series title Professional Paper
Series number 1615
DOI 10.3133/70180437
Year Published 2000
Language English
Publisher U.S. Geological Survey
Publisher location Denver, CO
Contributing office(s) Alaska Science Center, Alaska Science Center Geology Minerals, Eastern Geology and Paleoclimate Science Center
Description 10 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Geologic studies in Alaska by the U.S. Geological Survey, 1998 (Professional Paper 1615)
First page 179
Last page 188
Country United States
State Alaska
Other Geospatial Holy Cross quadrangle, Stuyahok gold placer deposits