Albert H Hofstra (Former Employee)
Science and Products
Filter Total Items: 82
Deep permeable fault–controlled helium transport and limited mantle flux in two extensional geothermal systems in the Great Basin, United States Deep permeable fault–controlled helium transport and limited mantle flux in two extensional geothermal systems in the Great Basin, United States
This study assesses the relative importance of deeply circulating meteoric water and direct mantle fluid inputs on near-surface 3He/4He anomalies reported at the Coso and Beowawe geothermal fields of the western United States. The depth of meteoric fluid circulation is a critical factor that controls the temperature, extent of fluid-rock isotope exchange, and mixing with deeply sourced...
Authors
Amlan Banerjee, Mark Person, Albert Hofstra, Donald S. Sweetkind, Denis Cohen, Andrew Sabin, Jeff Unruh, George Zyvoloski, Carl W. Gable, Laura Crossey, Karl Karlstrom
Geochemical and stable isotopic data on barren and mineralized drill core in the Devonian Popovich Formation, Screamer sector of the Betze-Post gold deposit, northern Carlin trend, Nevada Geochemical and stable isotopic data on barren and mineralized drill core in the Devonian Popovich Formation, Screamer sector of the Betze-Post gold deposit, northern Carlin trend, Nevada
The Devonian Popovich Formation is the major host for Carlin-type gold deposits in the northern Carlin trend of Nevada. The Popovich is composed of gray to black, thin-bedded, calcareous to dolomitic mudstone and limestone deposited near the carbonate platform margin. Carlin-type gold deposits are Eocene, disseminated, auriferous pyrite deposits characterized by acid leaching...
Authors
William D. Christiansen, Albert H. Hofstra, Pamela B. Zohar, Gilles Tousignant
Ages and sources of components of Zn-Pb, Cu, precious metal, and platinum group element deposits in the goodsprings district, Clark County, Nevada Ages and sources of components of Zn-Pb, Cu, precious metal, and platinum group element deposits in the goodsprings district, Clark County, Nevada
The Goodsprings district, Clark County, Nevada, includes zinc-dominant carbonate replacement deposits of probable late Paleozoic age, and lead-dominant carbonate replacement deposits, copper ± precious metal-platinum group element (PGE) deposits, and gold ± silver deposits that are spatially associated with Late Triassic porphyritic intrusions. The district encompasses ~500 km2 although...
Authors
Peter G. Vikre, Quentin J. Browne, Robert J. Fleck, Albert H. Hofstra, Joseph L. Wooden
Evaluation of the role of magmatic volatiles from Eocene mafic to felsic igneous rocks in the formation of Carlin-type gold deposits of the Carlin trend and Jerritt Canyon District as constrained by preliminary He, Pb, Sr, and Nd isotopic data Evaluation of the role of magmatic volatiles from Eocene mafic to felsic igneous rocks in the formation of Carlin-type gold deposits of the Carlin trend and Jerritt Canyon District as constrained by preliminary He, Pb, Sr, and Nd isotopic data
No abstract available.
Authors
Albert H. Hofstra, Gary P. Landis, Wayne R. Premo, M.W. Ressel, Christopher D. Henry
'Forensic' geochemical approaches to constrain the source of Au-Ag in low-sulfidation epithermal ores 'Forensic' geochemical approaches to constrain the source of Au-Ag in low-sulfidation epithermal ores
In order to better constrain genetic processes involved in forming mineral deposits (and ultimately exploration models), it helps to know from where the metals of interest are derived. How the metals arrived at their point of deposition, and why they were deposited there, are separate issues. We are using three different techniques in an attempt to better understand these processes for...
Authors
James A. Saunders, G. D. Kamenov, Albert H. Hofstra, D. L. Unger, R. A. Creaser, F. Barra
Paleozoic stratigraphy and kinematics of the Roberts Mountains allochthon in the Independence Mountains, northern Nevada Paleozoic stratigraphy and kinematics of the Roberts Mountains allochthon in the Independence Mountains, northern Nevada
New biostratigraphic, stratigraphic, and structural data from deformed lower Paleozoic sedimentary units of the Roberts Mountains allochthon (RMA), Independence Mountains, Nevada, have enabled the identification of stratigraphic units within the allochthon that range in age from Late Cambrian through Late Devonian. The McAfee thrust fault emplaced a relatively thick (>200 m) sheet of...
Authors
Christopher S. Holm-Denoma, Albert H. Hofstra, Stephen A. Leslie, Paula J. Noble
Science and Products
Filter Total Items: 82
Deep permeable fault–controlled helium transport and limited mantle flux in two extensional geothermal systems in the Great Basin, United States Deep permeable fault–controlled helium transport and limited mantle flux in two extensional geothermal systems in the Great Basin, United States
This study assesses the relative importance of deeply circulating meteoric water and direct mantle fluid inputs on near-surface 3He/4He anomalies reported at the Coso and Beowawe geothermal fields of the western United States. The depth of meteoric fluid circulation is a critical factor that controls the temperature, extent of fluid-rock isotope exchange, and mixing with deeply sourced...
Authors
Amlan Banerjee, Mark Person, Albert Hofstra, Donald S. Sweetkind, Denis Cohen, Andrew Sabin, Jeff Unruh, George Zyvoloski, Carl W. Gable, Laura Crossey, Karl Karlstrom
Geochemical and stable isotopic data on barren and mineralized drill core in the Devonian Popovich Formation, Screamer sector of the Betze-Post gold deposit, northern Carlin trend, Nevada Geochemical and stable isotopic data on barren and mineralized drill core in the Devonian Popovich Formation, Screamer sector of the Betze-Post gold deposit, northern Carlin trend, Nevada
The Devonian Popovich Formation is the major host for Carlin-type gold deposits in the northern Carlin trend of Nevada. The Popovich is composed of gray to black, thin-bedded, calcareous to dolomitic mudstone and limestone deposited near the carbonate platform margin. Carlin-type gold deposits are Eocene, disseminated, auriferous pyrite deposits characterized by acid leaching...
Authors
William D. Christiansen, Albert H. Hofstra, Pamela B. Zohar, Gilles Tousignant
Ages and sources of components of Zn-Pb, Cu, precious metal, and platinum group element deposits in the goodsprings district, Clark County, Nevada Ages and sources of components of Zn-Pb, Cu, precious metal, and platinum group element deposits in the goodsprings district, Clark County, Nevada
The Goodsprings district, Clark County, Nevada, includes zinc-dominant carbonate replacement deposits of probable late Paleozoic age, and lead-dominant carbonate replacement deposits, copper ± precious metal-platinum group element (PGE) deposits, and gold ± silver deposits that are spatially associated with Late Triassic porphyritic intrusions. The district encompasses ~500 km2 although...
Authors
Peter G. Vikre, Quentin J. Browne, Robert J. Fleck, Albert H. Hofstra, Joseph L. Wooden
Evaluation of the role of magmatic volatiles from Eocene mafic to felsic igneous rocks in the formation of Carlin-type gold deposits of the Carlin trend and Jerritt Canyon District as constrained by preliminary He, Pb, Sr, and Nd isotopic data Evaluation of the role of magmatic volatiles from Eocene mafic to felsic igneous rocks in the formation of Carlin-type gold deposits of the Carlin trend and Jerritt Canyon District as constrained by preliminary He, Pb, Sr, and Nd isotopic data
No abstract available.
Authors
Albert H. Hofstra, Gary P. Landis, Wayne R. Premo, M.W. Ressel, Christopher D. Henry
'Forensic' geochemical approaches to constrain the source of Au-Ag in low-sulfidation epithermal ores 'Forensic' geochemical approaches to constrain the source of Au-Ag in low-sulfidation epithermal ores
In order to better constrain genetic processes involved in forming mineral deposits (and ultimately exploration models), it helps to know from where the metals of interest are derived. How the metals arrived at their point of deposition, and why they were deposited there, are separate issues. We are using three different techniques in an attempt to better understand these processes for...
Authors
James A. Saunders, G. D. Kamenov, Albert H. Hofstra, D. L. Unger, R. A. Creaser, F. Barra
Paleozoic stratigraphy and kinematics of the Roberts Mountains allochthon in the Independence Mountains, northern Nevada Paleozoic stratigraphy and kinematics of the Roberts Mountains allochthon in the Independence Mountains, northern Nevada
New biostratigraphic, stratigraphic, and structural data from deformed lower Paleozoic sedimentary units of the Roberts Mountains allochthon (RMA), Independence Mountains, Nevada, have enabled the identification of stratigraphic units within the allochthon that range in age from Late Cambrian through Late Devonian. The McAfee thrust fault emplaced a relatively thick (>200 m) sheet of...
Authors
Christopher S. Holm-Denoma, Albert H. Hofstra, Stephen A. Leslie, Paula J. Noble