Nora Foley
Nora Foley is a Research Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Science and Products
Filter Total Items: 43
REE enrichment in granite-derived regolith deposits of the southeast United States: Prospective source rocks and accumulation processes
The Southeastern United States contains numerous anorogenic, or A-type, granites, which constitute promising source rocks for REE-enriched ion adsorption clay deposits due to their inherently high concentrations of REE. These granites have undergone a long history of chemical weathering, resulting in thick granite-derived regoliths, akin to those of South China, which supply virtually all heavy RE
Authors
Nora K. Foley, Robert A. Ayuso
Compilation of gallium resource data for bauxite deposits
Gallium (Ga) concentrations for bauxite deposits worldwide have been compiled from the literature to provide a basis for research regarding the occurrence and distribution of Ga worldwide, as well as between types of bauxite deposits. In addition, this report is an attempt to bring together reported Ga concentration data into one database to supplement ongoing U.S. Geological Survey studies of cri
Authors
Ruth F. Schulte, Nora K. Foley
Gold deposits of the Carolina Slate Belt, southeastern United States--Age and origin of the major gold producers
Gold- and iron sulfide-bearing deposits of the southeastern United States have distinctive mineralogical and geochemical features that provide a basis for constructing models of ore genesis for exploration and assessment of gold resources. The largest (historic) deposits, in approximate million ounces of gold (Moz Au), include those in the Haile (~ 4.2 Moz Au), Ridgeway (~1.5 Moz Au), Brewer (~0.2
Authors
Nora K. Foley, Robert A. Ayuso
Occurrence model for volcanogenic beryllium deposits
Current global and domestic mineral resources of beryllium (Be) for industrial uses are dominated by ores produced from deposits of the volcanogenic Be type. Beryllium deposits of this type can form where hydrothermal fluids interact with fluorine and lithophile-element (uranium, thorium, rubidium, lithium, beryllium, cesium, tantalum, rare earth elements, and tin) enriched volcanic rocks that con
Authors
Nora K. Foley, Albert H. Hofstra, David A. Lindsey, Robert R. Seal, Brian W. Jaskula, Nadine M. Piatak
The principal rare earth elements deposits of the United States: A summary of domestic deposits and a global perspective
Demand for the rare earth elements (REE, lanthanide elements) is estimated to be increasing at a rate of about 8% per year due to increasing applications in consumer products, computers, automobiles, aircraft, and other advanced technology products. Much of this demand growth is driven by new technologies that increase energy efficiency and substitute away from fossil fuels. Production of these el
Authors
Keith R. Long, Bradley S. Van Gosen, Nora K. Foley, Daniel Cordier
Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska
Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in high fiel
Authors
Cynthia Dusel-Bacon, Nora K. Foley, John E. Slack, Alan E. Koenig, Robert L. Oscarson
Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of
Authors
Cynthia Dusel-Bacon, John F. Slack, Alan E. Koenig, Nora K. Foley, Robert L. Oscarson, Kathleen D. Gans
The principal rare earth elements deposits of the United States: A summary of domestic deposits and a global perspective
The rare earth elements (REE) are fifteen elements with atomic numbers 57 through 71, from lanthanum to lutetium ('lanthanides'), plus yttrium (39), which is chemically similar to the lanthanide elements and thus typically included with the rare earth elements. Although industrial demand for these elements is relatively small in tonnage terms, they are essential for a diverse and expanding array o
Authors
Keith R. Long, Bradley S. Van Gosen, Nora K. Foley, Daniel Cordier
An occurrence model for the national assessment of volcanogenic beryllium deposits
The general occurrence model summarized here is intended to provide a descriptive basis for the identification and assessment of undiscovered beryllium deposits of a type and style similar to those found at Spor Mountain, Juab County, Utah. The assessment model is restricted in its application in order to provide a coherent basis for assessing the probability of the occurrence of similar economic
Authors
Nora K. Foley, Robert R. Seal, Nadine M. Piatak, Brianna Hetland
The role of ridge subduction in determining the geochemistry and Nd–Sr–Pb isotopic evolution of the Kodiak batholith in southern Alaska
The Paleocene Kodiak batholith, part of the Sanak–Baranof belt of Tertiary near-trench intrusive rocks, forms an elongate body (~ 150 km long) that transects Kodiak Island from SW to NE. The batholith consists of three zones (Southern, Central, and Northern) of kyanite-, muscovite-, and garnet-bearing biotite tonalite and granodiorite and less abundant granite that intruded an accretionary prism (
Authors
Robert A. Ayuso, Peter J. Haeussler, Dwight Bradley, David W. Farris, Nora K. Foley, Gregory A. Wandless
Mineral sources and transport pathways for arsenic release in a coastal watershed, USA
Metasedimentary bedrock of coastal Maine contains a diverse suite of As-bearing minerals that act as significant sources of elements found in ground and surface waters in the region. Arsenic sources in the Penobscot Formation include, in order of decreasing As content by weight: löllingite and realgar (c.70%), arsenopyrite, cobaltite, glaucodot, and gersdorffite (in the range of 34–45%), arsenian
Authors
Nora K. Foley, Robert A. Ayuso
Anthropogenic and natural lead isotopes in Fe-hydroxides and Fe-sulphates in a watershed associated with arsenic-enriched groundwater, Maine, USA
A survey of the natural and anthropogenic sources of lead contributing to secondary minerals in sulphidic schists associated with arsenic-enriched groundwater in Coastal Maine shows that the most likely source is natural Pb, particularly from coexisting sulphide minerals. The secondary minerals also reflect notable contributions from anthropogenic Pb. The Pb isotopes establish pathways by which Pb
Authors
Robert A. Ayuso, Nora K. Foley
Science and Products
Filter Total Items: 43
REE enrichment in granite-derived regolith deposits of the southeast United States: Prospective source rocks and accumulation processes
The Southeastern United States contains numerous anorogenic, or A-type, granites, which constitute promising source rocks for REE-enriched ion adsorption clay deposits due to their inherently high concentrations of REE. These granites have undergone a long history of chemical weathering, resulting in thick granite-derived regoliths, akin to those of South China, which supply virtually all heavy RE
Authors
Nora K. Foley, Robert A. Ayuso
Compilation of gallium resource data for bauxite deposits
Gallium (Ga) concentrations for bauxite deposits worldwide have been compiled from the literature to provide a basis for research regarding the occurrence and distribution of Ga worldwide, as well as between types of bauxite deposits. In addition, this report is an attempt to bring together reported Ga concentration data into one database to supplement ongoing U.S. Geological Survey studies of cri
Authors
Ruth F. Schulte, Nora K. Foley
Gold deposits of the Carolina Slate Belt, southeastern United States--Age and origin of the major gold producers
Gold- and iron sulfide-bearing deposits of the southeastern United States have distinctive mineralogical and geochemical features that provide a basis for constructing models of ore genesis for exploration and assessment of gold resources. The largest (historic) deposits, in approximate million ounces of gold (Moz Au), include those in the Haile (~ 4.2 Moz Au), Ridgeway (~1.5 Moz Au), Brewer (~0.2
Authors
Nora K. Foley, Robert A. Ayuso
Occurrence model for volcanogenic beryllium deposits
Current global and domestic mineral resources of beryllium (Be) for industrial uses are dominated by ores produced from deposits of the volcanogenic Be type. Beryllium deposits of this type can form where hydrothermal fluids interact with fluorine and lithophile-element (uranium, thorium, rubidium, lithium, beryllium, cesium, tantalum, rare earth elements, and tin) enriched volcanic rocks that con
Authors
Nora K. Foley, Albert H. Hofstra, David A. Lindsey, Robert R. Seal, Brian W. Jaskula, Nadine M. Piatak
The principal rare earth elements deposits of the United States: A summary of domestic deposits and a global perspective
Demand for the rare earth elements (REE, lanthanide elements) is estimated to be increasing at a rate of about 8% per year due to increasing applications in consumer products, computers, automobiles, aircraft, and other advanced technology products. Much of this demand growth is driven by new technologies that increase energy efficiency and substitute away from fossil fuels. Production of these el
Authors
Keith R. Long, Bradley S. Van Gosen, Nora K. Foley, Daniel Cordier
Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska
Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in high fiel
Authors
Cynthia Dusel-Bacon, Nora K. Foley, John E. Slack, Alan E. Koenig, Robert L. Oscarson
Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of
Authors
Cynthia Dusel-Bacon, John F. Slack, Alan E. Koenig, Nora K. Foley, Robert L. Oscarson, Kathleen D. Gans
The principal rare earth elements deposits of the United States: A summary of domestic deposits and a global perspective
The rare earth elements (REE) are fifteen elements with atomic numbers 57 through 71, from lanthanum to lutetium ('lanthanides'), plus yttrium (39), which is chemically similar to the lanthanide elements and thus typically included with the rare earth elements. Although industrial demand for these elements is relatively small in tonnage terms, they are essential for a diverse and expanding array o
Authors
Keith R. Long, Bradley S. Van Gosen, Nora K. Foley, Daniel Cordier
An occurrence model for the national assessment of volcanogenic beryllium deposits
The general occurrence model summarized here is intended to provide a descriptive basis for the identification and assessment of undiscovered beryllium deposits of a type and style similar to those found at Spor Mountain, Juab County, Utah. The assessment model is restricted in its application in order to provide a coherent basis for assessing the probability of the occurrence of similar economic
Authors
Nora K. Foley, Robert R. Seal, Nadine M. Piatak, Brianna Hetland
The role of ridge subduction in determining the geochemistry and Nd–Sr–Pb isotopic evolution of the Kodiak batholith in southern Alaska
The Paleocene Kodiak batholith, part of the Sanak–Baranof belt of Tertiary near-trench intrusive rocks, forms an elongate body (~ 150 km long) that transects Kodiak Island from SW to NE. The batholith consists of three zones (Southern, Central, and Northern) of kyanite-, muscovite-, and garnet-bearing biotite tonalite and granodiorite and less abundant granite that intruded an accretionary prism (
Authors
Robert A. Ayuso, Peter J. Haeussler, Dwight Bradley, David W. Farris, Nora K. Foley, Gregory A. Wandless
Mineral sources and transport pathways for arsenic release in a coastal watershed, USA
Metasedimentary bedrock of coastal Maine contains a diverse suite of As-bearing minerals that act as significant sources of elements found in ground and surface waters in the region. Arsenic sources in the Penobscot Formation include, in order of decreasing As content by weight: löllingite and realgar (c.70%), arsenopyrite, cobaltite, glaucodot, and gersdorffite (in the range of 34–45%), arsenian
Authors
Nora K. Foley, Robert A. Ayuso
Anthropogenic and natural lead isotopes in Fe-hydroxides and Fe-sulphates in a watershed associated with arsenic-enriched groundwater, Maine, USA
A survey of the natural and anthropogenic sources of lead contributing to secondary minerals in sulphidic schists associated with arsenic-enriched groundwater in Coastal Maine shows that the most likely source is natural Pb, particularly from coexisting sulphide minerals. The secondary minerals also reflect notable contributions from anthropogenic Pb. The Pb isotopes establish pathways by which Pb
Authors
Robert A. Ayuso, Nora K. Foley