TY - JOUR
T1 - Eocene fault-controlled fluid flow and mineralization in the Paradox Basin, United States
AU - Bailey, Lydia R.
AU - Kirk, Jason
AU - Hemming, Sidney R.
AU - Krantz, Robert W.
AU - Reiners, Peter W.
N1 - Funding Information:
Funding was provided by the W.M. Keck Foundation (Los Angeles, California, USA) and a Geological Society of America Student Research Grant. We acknowledge Juliet Crider and Mark Fischer for constructive reviews, and Lantz Indergard (Lisbon Valley Mining Co., La Sal, Utah), Carson Broaddus, Mark Barton, and Isabel Barton for help with sampling. We thank Uttam Chowdhury, Mary Kay Amistadi, and Tanzhuo Liu for laboratory assistance, and John Solum for providing illite XRD structure files.
Funding Information:
Funding was provided by the W.M. Keck Foundation (Los Angeles, California, USA) and a Geological Society of America Student Research Grant. We acknowledge Juliet Crider and Mark Fischer for constructive reviews, and Lantz Indergard (Lisbon Valley Mining Co., La Sal, Utah), Carson Broaddus, Mark Barton, and Isabel Barton for help with sampling. We thank Uttam Chowdhury, Mary Kay Amistadi, and Tanzhuo Liu for laboratory assistance, and John Solum for providing illite XRD structure files
Publisher Copyright:
© 2022 Geological Society of America
PY - 2022
Y1 - 2022
N2 - Sedimentary rocks of the Paradox Basin of the Colorado Plateau (southwestern USA) record widespread manifestations of paleo–fluid flow and fluid-rock reactions including Cu, U-V, and Fe-Mn mineral deposits, Si and Ca metasomatism, hydrocarbon accumulations, and bleached sandstones. Many of these are spatially associated with faults. Here we show evidence for a widespread phase of fault-related fluid migration and mineralization at 41–48 Ma in the Paradox Basin. We measured K-Ar dates of multiple size fractions of clay-rich fault gouge, yielding statistically overlapping dates of authigenic (1Md) illite for the Salt Valley (47.0 ± 3.0 Ma), Kane Springs (47.7 ± 3.8 Ma), Cliffdweller (43.4 ± 4.6 Ma), Courthouse (41.9 ± 2.3 Ma), Lisbon Valley (45.3 ± 0.9 Ma), and GTO (48.1 ± 2.6 Ma) faults. The latter two have an illite Rb-Sr isochron age of 50.9 ± 3.5 Ma, and fault-adjacent bornite has a Re-Os isochron age of 47.5 ± 1.5 Ma. Authigenic illite from a paleo–oil reservoir near the Courthouse fault formed from the interaction of reduced fluids with oxidized red-bed sandstones at 41.1 ± 2.5 Ma. The Moab and Keystone faults have older authigenic illite ages of 59.1 ± 5.7 Ma and 65.2 ± 1.0 Ma, respectively. Our results show a close temporal relationship between fault gouge formation, red-bed bleaching, and Cu mineralization during an enigmatic time interval, raising questions about drivers of Eocene fluid flow
AB - Sedimentary rocks of the Paradox Basin of the Colorado Plateau (southwestern USA) record widespread manifestations of paleo–fluid flow and fluid-rock reactions including Cu, U-V, and Fe-Mn mineral deposits, Si and Ca metasomatism, hydrocarbon accumulations, and bleached sandstones. Many of these are spatially associated with faults. Here we show evidence for a widespread phase of fault-related fluid migration and mineralization at 41–48 Ma in the Paradox Basin. We measured K-Ar dates of multiple size fractions of clay-rich fault gouge, yielding statistically overlapping dates of authigenic (1Md) illite for the Salt Valley (47.0 ± 3.0 Ma), Kane Springs (47.7 ± 3.8 Ma), Cliffdweller (43.4 ± 4.6 Ma), Courthouse (41.9 ± 2.3 Ma), Lisbon Valley (45.3 ± 0.9 Ma), and GTO (48.1 ± 2.6 Ma) faults. The latter two have an illite Rb-Sr isochron age of 50.9 ± 3.5 Ma, and fault-adjacent bornite has a Re-Os isochron age of 47.5 ± 1.5 Ma. Authigenic illite from a paleo–oil reservoir near the Courthouse fault formed from the interaction of reduced fluids with oxidized red-bed sandstones at 41.1 ± 2.5 Ma. The Moab and Keystone faults have older authigenic illite ages of 59.1 ± 5.7 Ma and 65.2 ± 1.0 Ma, respectively. Our results show a close temporal relationship between fault gouge formation, red-bed bleaching, and Cu mineralization during an enigmatic time interval, raising questions about drivers of Eocene fluid flow
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U2 - 10.1130/G49466.1
DO - 10.1130/G49466.1
M3 - Article
AN - SCOPUS:85125529679
VL - 50
SP - 326
EP - 330
JO - Geology
JF - Geology
SN - 0091-7613
IS - 3
ER -