John N Aleinikoff
John Aleinikoff is a Scientist Emeritus with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Electron microprobe analyses of feldspars and petrographic, geochemical, and geochronologic data from the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss in the Adirondacks of New York (ver. 2.0, May 2023) Electron microprobe analyses of feldspars and petrographic, geochemical, and geochronologic data from the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss in the Adirondacks of New York (ver. 2.0, May 2023)
Iron oxide-apatite (IOA) deposits of the Adirondack Mountains of New York locally contain elevated REE concentrations (e.g. Taylor and others, 2019). Critical to evaluating resource potential is understanding the genesis of the IOA deposits that host the REE-rich minerals. As part of this effort, the U.S. Geological Survey (USGS) is conducting bedrock geologic mapping, geochronology...
U-Pb SHRIMP and 40Ar/39Ar geochronologic data and backscatter electron (BSE) and panchromatic cathodoluminescent (CL) imagery of sample materials for study of dikes, country rock, and alteration systems, Butte, U.S.A. U-Pb SHRIMP and 40Ar/39Ar geochronologic data and backscatter electron (BSE) and panchromatic cathodoluminescent (CL) imagery of sample materials for study of dikes, country rock, and alteration systems, Butte, U.S.A.
These data are for a multidisciplinary study of dikes, country rock, and alteration systems, Butte, U.S.A. Results of the study are described and interpreted in Lund and others (2018). Data included are U-Pb SHRIMP geochronology for quartz porphyry dikes, 40Ar/39Ar thermochronologic data for biotite, hornblende, and K-feldspar from Butte granite country rock, and 40Ar/39Ar...
Geodatabase for the Blue Ridge Parkway in Virginia Geodatabase for the Blue Ridge Parkway in Virginia
The US Geological Survey, in cooperation with the National Park Service, conducted detailed geologic mapping on 35 7.5-minute quadrangles, within a 2-mile-wide+ corridor centered on the Parkway, from BLRI (Blue Ridge Parkway) Mile Post (MP) 0 near Afton, Virginia southward to MP 218 at Cumberland Knob, approximately 1.3 km south of the Virginia - North Carolina State Line. Detailed...
Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut
The bedrock geology of the Old Lyme quadrangle consists of Neoproterozoic and Permian gneisses and granites of the Gander and Avalon terranes, Silurian metasedimentary rocks of the Merrimack terrane, and Silurian to Devonian metasedimentary rocks of uncertain origin. The Avalon terrane rocks crop out within the Selden Neck block, and the Gander terrane rocks crop out within the Lyme dome...
Geologic Map of the Big Delta B-1 Quadrangle, East-Central Alaska Geologic Map of the Big Delta B-1 Quadrangle, East-Central Alaska
Geologic mapping and U-Pb age dating of rocks from the Big Delta B-1 quadrangle, east-central Alaska, have yielded new insights into the geology and gold mineral resource for the headwater region of the Goodpaster River, northeast of Delta, Alaska. The area lies within the Yukon-Tanana Upland and is underlain by Paleozoic and Cretaceous crystalline bedrock and contains several gold mines...
Geologic map of the Big Delta B-2 quadrangle, east-central Alaska Geologic map of the Big Delta B-2 quadrangle, east-central Alaska
New 1:63,360-scale geologic mapping of the Big Delta B-2 quadrangle provides important data on the structural setting and age of geologic units, as well as on the timing of gold mineralization plutonism within the Yukon-Tanana Upland of east-central Alaska. Gold exploration has remained active throughout the region in response to the discovery of the Pogo gold deposit, which lies within...
Map, tables, and summary of fossil and isotopic age data, Mount Hayes Quadrangle, eastern Alaska range, Alaska Map, tables, and summary of fossil and isotopic age data, Mount Hayes Quadrangle, eastern Alaska range, Alaska
This report describes, summarizes, and interprets all known bedrock fossil and isotopic age studies for the Mount Hayes quadrangle, eastern Alaska Range, Alaska. The accompanying map shows the location of all known bedrock fossil and isotopic sample localities in the quadrangle on a generalized geologic base map. These fossil and isotopic age data are obtained from new studies...
Filter Total Items: 109
Two-event genesis of Butte lode veins: Geologic and geochronologic evidence from ore veins, dikes, and host plutons Two-event genesis of Butte lode veins: Geologic and geochronologic evidence from ore veins, dikes, and host plutons
The long-standing ore-genesis model for world-class deposits of the Butte mining district, Montana, is of deep pre-Main Stage porphyry Cu-Mo and overlying Main Stage Ag-Zn-Cu-zoned lode veinsformed from discrete hydrothermal systems related to rhyolite dikes. The lode-specific model describes metals zones that formed in the lode veins as hydrothermal processes diminished in intensity...
Authors
Karen Lund, Ryan J. McAleer, John N. Aleinikoff, Michael Cosca
Two-event lode-ore deposition at Butte, USA: 40Ar/39Ar and U-Pb documentation of Ag-Au-polymetallic lodes overprinted by younger stockwork Cu-Mo ores and penecontemporaneous Cu lodes Two-event lode-ore deposition at Butte, USA: 40Ar/39Ar and U-Pb documentation of Ag-Au-polymetallic lodes overprinted by younger stockwork Cu-Mo ores and penecontemporaneous Cu lodes
The ore-genesis model for world-class deposits of the Butte mining district, Montana, USA, is deep pre-Main Stage porphyry Cu-Mo and overlying Main Stage Ag-Zn-Cu zoned-lode deposits, both of which formed from hydrothermal fluids driven by minor volumes of rhyolitic magma. The lode-specific model is that hydrothermal processes diminished in intensity outward from district center along...
Authors
Karen Lund, Ryan J. McAleer, John N. Aleinikoff, Michael A. Cosca, Michael J. Kunk
Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska
We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the...
Authors
Cynthia Dusel-Bacon, Christopher S. Holm-Denoma, James V. Jones, John N. Aleinikoff, James K. Mortensen
Petrology and geochronology of Mesoproterozoic basement of the Mount Rogers area of southwestern Virginia and northwestern North Carolina: Implications for the Precambrian tectonic evolution of the southern Blue Ridge province Petrology and geochronology of Mesoproterozoic basement of the Mount Rogers area of southwestern Virginia and northwestern North Carolina: Implications for the Precambrian tectonic evolution of the southern Blue Ridge province
Results from new geologic mapping, SHRIMP U-Pb geochronology, and petrologic studies indicate that Mesoproterozoic basement in the northern French Broad massif near Mount Rogers consists of multiple, mostly granitic plutons, map- and outcrop-scale xenoliths of pre-existing crustal rocks, and remnants of formerly overlying meta-sedimentary lithologies. Zircon and titanite ages demonstrate...
Authors
Richard P. Tollo, John N. Aleinikoff, Alan P. Dickin, Molly S. Radwany, C. Scott Southworth, C. Mark Fanning
Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C. Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C.
The Washington West 30’ × 60’ quadrangle covers an area of approximately 4,884 square kilometers (1,343 square miles) in and west of the Washington, D.C., metropolitan area. The eastern part of the area is highly urbanized, and more rural areas to the west are rapidly being developed. The area lies entirely within the Chesapeake Bay drainage basin and mostly within the Potomac River...
Authors
Peter T. Lyttle, John N. Aleinikoff, William C. Burton, E. Allen Crider, Avery A. Drake, Albert J. Froelich, J. Wright Horton, Gregorios Kasselas, Robert B. Mixon, Lucy McCartan, Arthur E. Nelson, Wayne L. Newell, Louis Pavlides, David S. Powars, C. Scott Southworth, Robert E. Weems
Geology along the Blue Ridge Parkway in Virginia Geology along the Blue Ridge Parkway in Virginia
Detailed geologic mapping and new SHRIMP (sensitive high-resolution ion microprobe) U-Pb zircon, Ar/Ar, Lu-Hf, 14C, luminescence (optically stimulated), thermochronology (fission-track), and palynology reveal the complex Mesoproterozoic to Quaternary geology along the ~350 km length of the Blue Ridge Parkway in Virginia. Traversing the boundary of the central and southern Appalachians...
Authors
Mark W. Carter, C. Scott Southworth, Richard P. Tollo, Arthur J. Merschat, Sara Wagner, Ava Lazor, John N. Aleinikoff
Science and Products
Electron microprobe analyses of feldspars and petrographic, geochemical, and geochronologic data from the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss in the Adirondacks of New York (ver. 2.0, May 2023) Electron microprobe analyses of feldspars and petrographic, geochemical, and geochronologic data from the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss in the Adirondacks of New York (ver. 2.0, May 2023)
Iron oxide-apatite (IOA) deposits of the Adirondack Mountains of New York locally contain elevated REE concentrations (e.g. Taylor and others, 2019). Critical to evaluating resource potential is understanding the genesis of the IOA deposits that host the REE-rich minerals. As part of this effort, the U.S. Geological Survey (USGS) is conducting bedrock geologic mapping, geochronology...
U-Pb SHRIMP and 40Ar/39Ar geochronologic data and backscatter electron (BSE) and panchromatic cathodoluminescent (CL) imagery of sample materials for study of dikes, country rock, and alteration systems, Butte, U.S.A. U-Pb SHRIMP and 40Ar/39Ar geochronologic data and backscatter electron (BSE) and panchromatic cathodoluminescent (CL) imagery of sample materials for study of dikes, country rock, and alteration systems, Butte, U.S.A.
These data are for a multidisciplinary study of dikes, country rock, and alteration systems, Butte, U.S.A. Results of the study are described and interpreted in Lund and others (2018). Data included are U-Pb SHRIMP geochronology for quartz porphyry dikes, 40Ar/39Ar thermochronologic data for biotite, hornblende, and K-feldspar from Butte granite country rock, and 40Ar/39Ar...
Geodatabase for the Blue Ridge Parkway in Virginia Geodatabase for the Blue Ridge Parkway in Virginia
The US Geological Survey, in cooperation with the National Park Service, conducted detailed geologic mapping on 35 7.5-minute quadrangles, within a 2-mile-wide+ corridor centered on the Parkway, from BLRI (Blue Ridge Parkway) Mile Post (MP) 0 near Afton, Virginia southward to MP 218 at Cumberland Knob, approximately 1.3 km south of the Virginia - North Carolina State Line. Detailed...
Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut
The bedrock geology of the Old Lyme quadrangle consists of Neoproterozoic and Permian gneisses and granites of the Gander and Avalon terranes, Silurian metasedimentary rocks of the Merrimack terrane, and Silurian to Devonian metasedimentary rocks of uncertain origin. The Avalon terrane rocks crop out within the Selden Neck block, and the Gander terrane rocks crop out within the Lyme dome...
Geologic Map of the Big Delta B-1 Quadrangle, East-Central Alaska Geologic Map of the Big Delta B-1 Quadrangle, East-Central Alaska
Geologic mapping and U-Pb age dating of rocks from the Big Delta B-1 quadrangle, east-central Alaska, have yielded new insights into the geology and gold mineral resource for the headwater region of the Goodpaster River, northeast of Delta, Alaska. The area lies within the Yukon-Tanana Upland and is underlain by Paleozoic and Cretaceous crystalline bedrock and contains several gold mines...
Geologic map of the Big Delta B-2 quadrangle, east-central Alaska Geologic map of the Big Delta B-2 quadrangle, east-central Alaska
New 1:63,360-scale geologic mapping of the Big Delta B-2 quadrangle provides important data on the structural setting and age of geologic units, as well as on the timing of gold mineralization plutonism within the Yukon-Tanana Upland of east-central Alaska. Gold exploration has remained active throughout the region in response to the discovery of the Pogo gold deposit, which lies within...
Map, tables, and summary of fossil and isotopic age data, Mount Hayes Quadrangle, eastern Alaska range, Alaska Map, tables, and summary of fossil and isotopic age data, Mount Hayes Quadrangle, eastern Alaska range, Alaska
This report describes, summarizes, and interprets all known bedrock fossil and isotopic age studies for the Mount Hayes quadrangle, eastern Alaska Range, Alaska. The accompanying map shows the location of all known bedrock fossil and isotopic sample localities in the quadrangle on a generalized geologic base map. These fossil and isotopic age data are obtained from new studies...
Filter Total Items: 109
Two-event genesis of Butte lode veins: Geologic and geochronologic evidence from ore veins, dikes, and host plutons Two-event genesis of Butte lode veins: Geologic and geochronologic evidence from ore veins, dikes, and host plutons
The long-standing ore-genesis model for world-class deposits of the Butte mining district, Montana, is of deep pre-Main Stage porphyry Cu-Mo and overlying Main Stage Ag-Zn-Cu-zoned lode veinsformed from discrete hydrothermal systems related to rhyolite dikes. The lode-specific model describes metals zones that formed in the lode veins as hydrothermal processes diminished in intensity...
Authors
Karen Lund, Ryan J. McAleer, John N. Aleinikoff, Michael Cosca
Two-event lode-ore deposition at Butte, USA: 40Ar/39Ar and U-Pb documentation of Ag-Au-polymetallic lodes overprinted by younger stockwork Cu-Mo ores and penecontemporaneous Cu lodes Two-event lode-ore deposition at Butte, USA: 40Ar/39Ar and U-Pb documentation of Ag-Au-polymetallic lodes overprinted by younger stockwork Cu-Mo ores and penecontemporaneous Cu lodes
The ore-genesis model for world-class deposits of the Butte mining district, Montana, USA, is deep pre-Main Stage porphyry Cu-Mo and overlying Main Stage Ag-Zn-Cu zoned-lode deposits, both of which formed from hydrothermal fluids driven by minor volumes of rhyolitic magma. The lode-specific model is that hydrothermal processes diminished in intensity outward from district center along...
Authors
Karen Lund, Ryan J. McAleer, John N. Aleinikoff, Michael A. Cosca, Michael J. Kunk
Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska
We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the...
Authors
Cynthia Dusel-Bacon, Christopher S. Holm-Denoma, James V. Jones, John N. Aleinikoff, James K. Mortensen
Petrology and geochronology of Mesoproterozoic basement of the Mount Rogers area of southwestern Virginia and northwestern North Carolina: Implications for the Precambrian tectonic evolution of the southern Blue Ridge province Petrology and geochronology of Mesoproterozoic basement of the Mount Rogers area of southwestern Virginia and northwestern North Carolina: Implications for the Precambrian tectonic evolution of the southern Blue Ridge province
Results from new geologic mapping, SHRIMP U-Pb geochronology, and petrologic studies indicate that Mesoproterozoic basement in the northern French Broad massif near Mount Rogers consists of multiple, mostly granitic plutons, map- and outcrop-scale xenoliths of pre-existing crustal rocks, and remnants of formerly overlying meta-sedimentary lithologies. Zircon and titanite ages demonstrate...
Authors
Richard P. Tollo, John N. Aleinikoff, Alan P. Dickin, Molly S. Radwany, C. Scott Southworth, C. Mark Fanning
Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C. Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C.
The Washington West 30’ × 60’ quadrangle covers an area of approximately 4,884 square kilometers (1,343 square miles) in and west of the Washington, D.C., metropolitan area. The eastern part of the area is highly urbanized, and more rural areas to the west are rapidly being developed. The area lies entirely within the Chesapeake Bay drainage basin and mostly within the Potomac River...
Authors
Peter T. Lyttle, John N. Aleinikoff, William C. Burton, E. Allen Crider, Avery A. Drake, Albert J. Froelich, J. Wright Horton, Gregorios Kasselas, Robert B. Mixon, Lucy McCartan, Arthur E. Nelson, Wayne L. Newell, Louis Pavlides, David S. Powars, C. Scott Southworth, Robert E. Weems
Geology along the Blue Ridge Parkway in Virginia Geology along the Blue Ridge Parkway in Virginia
Detailed geologic mapping and new SHRIMP (sensitive high-resolution ion microprobe) U-Pb zircon, Ar/Ar, Lu-Hf, 14C, luminescence (optically stimulated), thermochronology (fission-track), and palynology reveal the complex Mesoproterozoic to Quaternary geology along the ~350 km length of the Blue Ridge Parkway in Virginia. Traversing the boundary of the central and southern Appalachians...
Authors
Mark W. Carter, C. Scott Southworth, Richard P. Tollo, Arthur J. Merschat, Sara Wagner, Ava Lazor, John N. Aleinikoff