John F. Slack
John Slack is a Scientist Emeritus with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Science and Products
Filter Total Items: 69
Geochemistry and jasper beds from the Ordovician Løkken ophiolite, Norway: origin of proximal and distal siliceous exhalites Geochemistry and jasper beds from the Ordovician Løkken ophiolite, Norway: origin of proximal and distal siliceous exhalites
Stratiform beds of jasper (hematitic chert), composed essentially of SiO2 (69–95 wt %) and Fe2O3 (3–25 wt %), can be traced several kilometers along strike in the Ordovician Løkken ophiolite, Norway. These siliceous beds are closely associated with volcanogenic massive sulfide (VMS) deposits and are interpreted as sea-floor gels that were deposited by fallout from hydrothermal plumes in...
Authors
Tor Grenne, John F. Slack
Whole rock geochemical data For altered and mineralized rocks, Red Dog Zn-Pb-Ag District, western Brooks Range, Alaska Whole rock geochemical data For altered and mineralized rocks, Red Dog Zn-Pb-Ag District, western Brooks Range, Alaska
No abstract available.
Authors
John F. Slack, Karen D. Kelley, Jeffrey L. Clark
Whole rock geochemical data For paleozoic sedimentary rocks of the western Brooks Range, Alaska Whole rock geochemical data For paleozoic sedimentary rocks of the western Brooks Range, Alaska
No abstract available.
Authors
John F. Slack, Jeanine M. Schmidt, Julie A. Dumoulin
Paleozoic sedimentary rocks in the Red Dog Zn-Pb-Ag district and vicinity, western Brooks Range, Alaska: provenance, deposition, and metallogenic significance Paleozoic sedimentary rocks in the Red Dog Zn-Pb-Ag district and vicinity, western Brooks Range, Alaska: provenance, deposition, and metallogenic significance
Geochemical analyses of Paleozoic sedimentary rocks in the western Brooks Range reveal a complex evolutionary history for strata surrounding the large Zn-Pb-Ag deposits of the Red Dog district. Data for major elements, trace elements, and rare earth elements (REE) were obtained on 220 samples of unaltered and unmineralized siliciclastic rocks from the Upper Devonian-Lower Mississippian...
Authors
John F. Slack, Julie A. Dumoulin, J.M. Schmidt, L. E. Young, Cameron Rombach
Bedded jaspers of the Ordovician Løkken ophiolite, Norway: seafloor deposition and diagenetic maturation of hydrothermal plume-derived silica-iron gels Bedded jaspers of the Ordovician Løkken ophiolite, Norway: seafloor deposition and diagenetic maturation of hydrothermal plume-derived silica-iron gels
Sedimentary beds of jasper (red hematitic chert) in the Ordovician Løkken ophiolite of Norway are closely associated with volcanogenic massive sulphide (VMS) deposits. The jaspers occur in the immediate hangingwall and laterally peripheral to the large Løkken (25–30 Mt) and small Høydal (0.1 Mt) VMS deposits, and are exposed discontinuously for several kilometres along strike. Massive or...
Authors
Tor Grenne, John F. Slack
Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan Mountains, Colorado Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan Mountains, Colorado
This paper presents 25 new 40Ar/39Ar dates from the main calc-alkaline ash-flow sheets and related younger plutons of the western San Juan volcanic field, the ash-flow sheets of the Lake City caldera cycle, and veins and other altered rocks in the Lake City region. The goal of the study was to produce similar quality 40Ar/39Ar ages to those currently published for the eastern and central...
Authors
Dana J. Bove, Ken Hon, Karin E. Budding, John F. Slack, Lawrence W. Snee, Ross A. Yeoman
Sm-Nd dating of the giant Sullivan Pb-Zn-Ag deposit, British Columbia Sm-Nd dating of the giant Sullivan Pb-Zn-Ag deposit, British Columbia
We report here Sm and Nd isotope data for hydrothermal tourmalinites and sulfide ores from the giant Sullivan Pb-Zn-Ag deposit, which occurs in the lower part of the Mesoproterozoic Purcell (Belt) Supergroup. Whole-rock samples of quartz-tourmaline tourmalinite from the footwall alteration pipe yield a Sm-Nd isochron age of 1470 ± 59 Ma, recording synsedimentary B metasomatism of clastic...
Authors
Shao-Yong Jiang, John F. Slack, Martin R. Palmer
Alkali-deficient tourmaline from the Sullivan Pb-Zn-Ag deposit, British Columbia Alkali-deficient tourmaline from the Sullivan Pb-Zn-Ag deposit, British Columbia
Alkali-deficient tourmalines are found in albitized rocks from the hanging-wall of the Sullivan Pb-Zn-Ag deposit (British Columbia, Canada). They approximate the Mg-equivalent of foitite with an idealized formula □(Mg2Al)Al6Si6O18(BO3)3(OH)4. Major chemical substitutions in the tourmalines are the alkali-defect type [Na*(x) + Mg*(Y) = □(x) + Al(Y)] and the uvite type [Na*(x) + Al(Y) = Ca...
Authors
Shao-Yong Jiang, John F. Slack, Martin R. Palmer
USGS research on mineral resources, 1991; program and abstracts USGS research on mineral resources, 1991; program and abstracts
No abstract available.
Authors
Elizabeth E. Good, John F. Slack, Rama K. Kotra
Mineral resources of the Citico Creek Wilderness Study Area, Monroe County, Tennessee Mineral resources of the Citico Creek Wilderness Study Area, Monroe County, Tennessee
No abstract available.
Authors
John F. Slack, E. R. Force, P. T. Behum, B. B. Williams
Mineral resources of the Big Frog Wilderness Study Area and additions, Polk County, Tennessee and Fannin County, Georgia Mineral resources of the Big Frog Wilderness Study Area and additions, Polk County, Tennessee and Fannin County, Georgia
No abstract available.
Authors
John F. Slack, Gertrude C. Gazdik, Maynard L. Dunn
Science and Products
Filter Total Items: 69
Geochemistry and jasper beds from the Ordovician Løkken ophiolite, Norway: origin of proximal and distal siliceous exhalites Geochemistry and jasper beds from the Ordovician Løkken ophiolite, Norway: origin of proximal and distal siliceous exhalites
Stratiform beds of jasper (hematitic chert), composed essentially of SiO2 (69–95 wt %) and Fe2O3 (3–25 wt %), can be traced several kilometers along strike in the Ordovician Løkken ophiolite, Norway. These siliceous beds are closely associated with volcanogenic massive sulfide (VMS) deposits and are interpreted as sea-floor gels that were deposited by fallout from hydrothermal plumes in...
Authors
Tor Grenne, John F. Slack
Whole rock geochemical data For altered and mineralized rocks, Red Dog Zn-Pb-Ag District, western Brooks Range, Alaska Whole rock geochemical data For altered and mineralized rocks, Red Dog Zn-Pb-Ag District, western Brooks Range, Alaska
No abstract available.
Authors
John F. Slack, Karen D. Kelley, Jeffrey L. Clark
Whole rock geochemical data For paleozoic sedimentary rocks of the western Brooks Range, Alaska Whole rock geochemical data For paleozoic sedimentary rocks of the western Brooks Range, Alaska
No abstract available.
Authors
John F. Slack, Jeanine M. Schmidt, Julie A. Dumoulin
Paleozoic sedimentary rocks in the Red Dog Zn-Pb-Ag district and vicinity, western Brooks Range, Alaska: provenance, deposition, and metallogenic significance Paleozoic sedimentary rocks in the Red Dog Zn-Pb-Ag district and vicinity, western Brooks Range, Alaska: provenance, deposition, and metallogenic significance
Geochemical analyses of Paleozoic sedimentary rocks in the western Brooks Range reveal a complex evolutionary history for strata surrounding the large Zn-Pb-Ag deposits of the Red Dog district. Data for major elements, trace elements, and rare earth elements (REE) were obtained on 220 samples of unaltered and unmineralized siliciclastic rocks from the Upper Devonian-Lower Mississippian...
Authors
John F. Slack, Julie A. Dumoulin, J.M. Schmidt, L. E. Young, Cameron Rombach
Bedded jaspers of the Ordovician Løkken ophiolite, Norway: seafloor deposition and diagenetic maturation of hydrothermal plume-derived silica-iron gels Bedded jaspers of the Ordovician Løkken ophiolite, Norway: seafloor deposition and diagenetic maturation of hydrothermal plume-derived silica-iron gels
Sedimentary beds of jasper (red hematitic chert) in the Ordovician Løkken ophiolite of Norway are closely associated with volcanogenic massive sulphide (VMS) deposits. The jaspers occur in the immediate hangingwall and laterally peripheral to the large Løkken (25–30 Mt) and small Høydal (0.1 Mt) VMS deposits, and are exposed discontinuously for several kilometres along strike. Massive or...
Authors
Tor Grenne, John F. Slack
Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan Mountains, Colorado Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan Mountains, Colorado
This paper presents 25 new 40Ar/39Ar dates from the main calc-alkaline ash-flow sheets and related younger plutons of the western San Juan volcanic field, the ash-flow sheets of the Lake City caldera cycle, and veins and other altered rocks in the Lake City region. The goal of the study was to produce similar quality 40Ar/39Ar ages to those currently published for the eastern and central...
Authors
Dana J. Bove, Ken Hon, Karin E. Budding, John F. Slack, Lawrence W. Snee, Ross A. Yeoman
Sm-Nd dating of the giant Sullivan Pb-Zn-Ag deposit, British Columbia Sm-Nd dating of the giant Sullivan Pb-Zn-Ag deposit, British Columbia
We report here Sm and Nd isotope data for hydrothermal tourmalinites and sulfide ores from the giant Sullivan Pb-Zn-Ag deposit, which occurs in the lower part of the Mesoproterozoic Purcell (Belt) Supergroup. Whole-rock samples of quartz-tourmaline tourmalinite from the footwall alteration pipe yield a Sm-Nd isochron age of 1470 ± 59 Ma, recording synsedimentary B metasomatism of clastic...
Authors
Shao-Yong Jiang, John F. Slack, Martin R. Palmer
Alkali-deficient tourmaline from the Sullivan Pb-Zn-Ag deposit, British Columbia Alkali-deficient tourmaline from the Sullivan Pb-Zn-Ag deposit, British Columbia
Alkali-deficient tourmalines are found in albitized rocks from the hanging-wall of the Sullivan Pb-Zn-Ag deposit (British Columbia, Canada). They approximate the Mg-equivalent of foitite with an idealized formula □(Mg2Al)Al6Si6O18(BO3)3(OH)4. Major chemical substitutions in the tourmalines are the alkali-defect type [Na*(x) + Mg*(Y) = □(x) + Al(Y)] and the uvite type [Na*(x) + Al(Y) = Ca...
Authors
Shao-Yong Jiang, John F. Slack, Martin R. Palmer
USGS research on mineral resources, 1991; program and abstracts USGS research on mineral resources, 1991; program and abstracts
No abstract available.
Authors
Elizabeth E. Good, John F. Slack, Rama K. Kotra
Mineral resources of the Citico Creek Wilderness Study Area, Monroe County, Tennessee Mineral resources of the Citico Creek Wilderness Study Area, Monroe County, Tennessee
No abstract available.
Authors
John F. Slack, E. R. Force, P. T. Behum, B. B. Williams
Mineral resources of the Big Frog Wilderness Study Area and additions, Polk County, Tennessee and Fannin County, Georgia Mineral resources of the Big Frog Wilderness Study Area and additions, Polk County, Tennessee and Fannin County, Georgia
No abstract available.
Authors
John F. Slack, Gertrude C. Gazdik, Maynard L. Dunn