Ric is a Research Geologist for the Alaska Science Center.
Science and Products
Filter Total Items: 111
Preliminary geologic map of the Greater Antilles and the Virgin Islands
IntroductionThis geologic map of the Greater Antilles and the Virgin Islands is a compilation of information from the literature, integrated to provide a seamless geologic map of the region. The geology shown on sheet 1 covers Cuba, the island of Hispaniola, which includes Haiti and the Dominican Republic, Jamaica, the Cayman Islands, Puerto Rico, and the U.S. and British Virgin Islands. A second
Probabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report
The U.S. Geological Survey is partnering with the IberoAmerican Association of Geological and Mining Surveys (ASGMI) to conduct an assessment of undiscovered metallic and non-metallic resources in the Greater Antilles region. The assessment plans to provide science-based information on the geologic availability of these resources for development, land-use planning, and decision making. The USGS an
Legacy K/Ar and 40Ar/39Ar geochronologic data from the Alaska-Aleutian Range batholith of south-central Alaska
Sample descriptions and analytical data for more than 200 K/Ar and 40Ar/39Ar analyses from rocks of the Alaska-Aleutian Range batholith of south-central Alaska are reported here. Samples were collected over a period of 20 years by Bruce R. Reed and Marvin A. Lanphere (both U.S. Geological Survey) as part of their studies of the batholith.
Use of Landsat MSS and TM imagery to improve reconnaissance geologic mapping in the Ruby quadrangle, west-central Alaska: A section in Geological studies in Alaska by the U.S. Geological Survey, 1999
By using Multispectral Scanner (MSS) and Thematic Mapper (TM) satellite images, the spatial relation of units JMtu (mafic, ultramafic, and sedimentary rocks, undivided) and PzZrqs (pelitic and quartzitic schist) of Wilson and others (1998) from the northeastern portion of the Ruby 1:250,000-scale quadrangle geologic map was further defined. The MSS image was first analyzed using spectral signature
Eruption in an ice-filled caldera, Mount Veniaminof, Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1983
The more prominent of the two visible intracaldera cones of Mount Veniaminof went into eruption in early June 1983 and continued until early April 1984. Veniaminof is a 2,507-m-high composite cone having an 8 x 11-km summit caldera which formed 3,300-3,700 yr B.P. (Miller and Smith, 1977). The active 1.6x1.2-km cone protrudes 200 m through the glacial ice filling the caldera; it lies in a 60-m-lon
Geologic setting, petrology, and age of Pliocene to Holocene volcanoes of the Stepovak Bay area, western Alaska Peninsula: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1988
Five volcanoes are situated north of Stepovak Bay on the western Alaska Peninsula; only one of these, Kupreanof volcano, had been reported prior to USGS reconnaissance geologic mapping of the area between 1982 and 1986. The volcanoes overlie sedimentary rocks of Eocene to late Miocene age and welded(?) tuff deposits of uncertain, but presumably late Tertiary, age. All five of the volcanoes are ali
Radiometric age file for Alaska: A section in The United States Geological Survey in Alaska: Accomplishments during 1980
The Alaska radiometric age file of the Branch of Alaskan Geology is a computer-based compilation of radiometric dates from the state of Alaska and the western parts of the Yukon Territory and British Columbia. More than 1800 age determinations from over 250 references have been entered in the file. References date back to 1958 and include both published and unpublished sources. The file is the out
Digital image processing techniques for detecting surface alteration - An application on the Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1983
The tectonic evolution of the Alaska Peninsula makes it a likely area for the discovery of significant mineral deposits. However, because of problems associated with remoteness and poor weather, little detailed mineral exploration work has been carried on there. This study focuses on using Landsat multispectral scanner data for the Port Moller, Stepovak Bay, and Simeon of Island Quadrangles to det
Later Paleozoic and Early Jurassic fossil ages from the McHugh Complex: A section in Geologic studies in Alaska by the U.S. Geological Survey during 1985 Circular 978
Late Mississippian through Early Pennsylvanian and Early Jurassic microfossils were collected from the type locality of the McHugh Complex (Clark, 1973) along the Seward Highway southeast of Anchorage (fig. 36). Radiolarians collected indicate that same of the oceanic rocks in the McHugh Complex are Early Jurassic in age. Conodonts extracted from a conglomerate clast are of Late Mississippian thro
Geology and mineral resources of the Port Moller region, western Alaska Peninsula, Aleutian arc: A section in USGS research on mineral resources - 1989: Program and abstracts
Geologic mapping of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles was begun under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP) in 1983 . Two important mineral deposits are located in the Port Moller quadrangle; the Pyramid prospect is the largest copper porphyry system in the Aleutian Arc, and the Apollo Mine is the only gold mine to reach production stat
Apparent episodicity of magmatic activity based on radiometric age determination: A section in The United States Geological Survey in Alaska: Accomplishments during 1980
Results of recent potassium-argon age studies in the Chignik region, Alaska, (Wilson, 1980; Wilson and others, 1982) have suggested a distinct episodicity in igneous activity during Tertiary time. To date work on the Aleutian magmatic arc indicates that plutonic activity took place along the present outer Pacific margin and in the northern Alaska-Aleutian Range batholith (Reed and Lanphere, 1973;
Creation of a full color geologic map by computer: A case history from the Port Moller project resource assessment, Alaska Peninsula: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1988
Graphics programs on computers can facilitate the compilation and production of geologic maps, including full color maps of publication quality. This paper describes the application of two different programs, GSMAP and ARC/INFO, to the production of a geologic map of the Port Meller and adjacent 1:250,000-scale quadrangles on the Alaska Peninsula. GSMAP was used at first because of easy digitizing
Alaska Resource Data File
The Alaska Resource Data File (ARDF) site provides descriptions of mines, prospects, and mineral occurrences for individual U.S. Geological Survey 1:250,000-scale quadrangles in Alaska.
Geologic Map of Alaska
In January 2016, the U.S. Geological Survey released the first ever digital geologic map of Alaska. This map reflects more than a century of work and provides a visual context for the abundant mineral and energy resources found throughout the state. The map also is available to use in three different formats: a professional GIS database, a public interactive version via a web browser, and an...
Filter Total Items: 28
Bedrock geologic map of the 15' Sleetmute A-2 quadrangle, southwestern Alaska
Twelve unnamed, bedrock stratigraphic units are recognized within the Sleetmute A-2 1:63,360-scale quadrangle of southwestern Alaska. These units range in age from late(?) Proterozoic through Devonian and can be divided into two distinct facies belts: (1) a southern facies of dominantly shallow-water platform carbonate and minor siliciclastic rocks (including Early Ordovician–Early Devonian platfo
Surficial geologic map of the Dillingham quadrangle, southwestern Alaska
The geologic map of the Dillingham quadrangle in southwestern Alaska shows surficial unconsolidated deposits, many of which are alluvial or glacial in nature. The map area, part of Alaska that was largely not glaciated during the late Wisconsin glaciation, has a long history reflecting local and more distant glaciations. Late Wisconsin glacial deposits have limited extent in the eastern part of th
Reconnaissance surficial geologic map of the Taylor Mountains quadrangle, southwestern Alaska
This map and accompanying digital files are the result of the interpretation of aerial photographs from the 1950s as well as more modern imagery. The area, long considered a part of Alaska that was largely not glaciated (see Karlstrom, 1964; Coulter and others, 1965; or Péwé, 1975), actually has a long history reflecting local and more distant glaciations. An unpublished photogeologic map of the T
Reconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska
The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex (Kilbuck terrane) to Quaternary age mafic volcanic rocks of Nunivak Island. The map area encompasses much of the type area of the Togiak-Tikchik Complex. The geologic maps used to construct this compilation were, for the most part, reconnaissance studies done in the time period from the 1950s
Reconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska
The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex (Kilbuck terrane) to Quaternary age mafic volcanic rocks of Nunivak Island. The map area encompasses much of the type area of the Togiak-Tikchik Complex. The geologic maps used to construct this compilation were, for the most part, reconnaissance studies done in the time period from the 1950s
Reconnaissance geologic map of Kodiak Island and adjacent islands, Alaska
Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best avail
Geology of the Prince William Sound and Kenai Peninsula region, Alaska: Including the Kenai, Seldovia, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles
The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world’s largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska and Aleutian Ranges and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper Riv
Geology of the Prince William Sound and Kenai Peninsula region, Alaska: Including the Kenai, Seldovia, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles
The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world’s largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska and Aleutian Ranges and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper Riv
Geologic map of the Cook Inlet region, Alaska, including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale quadrangles
In 1976, L.B. Magoon, W.L. Adkinson, and R.M. Egbert published a major geologic map of the Cook Inlet region, which has served well as a compilation of existing information and a guide for future research and mapping. The map in this report updates Magoon and others (1976) and incorporates new and additional mapping and interpretation. This map is also a revision of areas of overlap with the geolo
Geologic Map of the Yukon-Koyukuk Basin, Alaska
This map and accompanying digital files represent part of a systematic effort to release geologic data for the United States in a uniform manner. All the geologic data in this series will be published as parts of the U.S. Geological Survey Data Series. The geologic data in this series have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale fi
World heritage site - Bien du Patrimoine Mondial - Kluane/Wrangell-St. Elias/Glacier Bay/Tatshenshini-Alsek
The four parks depicted on this map make up a single World Heritage Site that covers 24.3 million acres. Together, they comprise the largest internationally protected land-based ecosystem on the planet. The United Nations Educational, Scientific and Cultural Organization (UNESCO) established the World Heritage Program in 1972 for the identification and protection of the world?s irreplaceable natur
Geochemical and 40Ar/39Ar Analytical Data of Rocks from Glacier Bay National Park and Preserve
This data set contains major and trace element geochemical data and 40Ar/39Ar isotopic data and ages for rock samples collected during 2016 fieldwork in Glacier Bay National Park and Preserve. The plutonic rock samples were collected for radiometric age determinations to test for the presence of the Late Jurassic to Early Cretaceous (130-160 Ma) Saint Elias suite. The age analyses indicate that al
U-Pb zircon data for: Cretaceous plutonic rocks of western Glacier Bay National Park and Preserve
In 2016, with National Park Service support, several previously undated plutons were sampled in Glacier Bay National Park and Preserve along the west side of Glacier Bay for age determinations. Geochronologic analyses were conducted to determine the ages of the plutonic rocks in the Glacier Bay area. Five samples were collected by Frederic Wilson (USGS Alaska Science Center), from Dundas Bay and G
Science and Products
- Publications
Filter Total Items: 111
Preliminary geologic map of the Greater Antilles and the Virgin Islands
IntroductionThis geologic map of the Greater Antilles and the Virgin Islands is a compilation of information from the literature, integrated to provide a seamless geologic map of the region. The geology shown on sheet 1 covers Cuba, the island of Hispaniola, which includes Haiti and the Dominican Republic, Jamaica, the Cayman Islands, Puerto Rico, and the U.S. and British Virgin Islands. A secondProbabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report
The U.S. Geological Survey is partnering with the IberoAmerican Association of Geological and Mining Surveys (ASGMI) to conduct an assessment of undiscovered metallic and non-metallic resources in the Greater Antilles region. The assessment plans to provide science-based information on the geologic availability of these resources for development, land-use planning, and decision making. The USGS anLegacy K/Ar and 40Ar/39Ar geochronologic data from the Alaska-Aleutian Range batholith of south-central Alaska
Sample descriptions and analytical data for more than 200 K/Ar and 40Ar/39Ar analyses from rocks of the Alaska-Aleutian Range batholith of south-central Alaska are reported here. Samples were collected over a period of 20 years by Bruce R. Reed and Marvin A. Lanphere (both U.S. Geological Survey) as part of their studies of the batholith.Use of Landsat MSS and TM imagery to improve reconnaissance geologic mapping in the Ruby quadrangle, west-central Alaska: A section in Geological studies in Alaska by the U.S. Geological Survey, 1999
By using Multispectral Scanner (MSS) and Thematic Mapper (TM) satellite images, the spatial relation of units JMtu (mafic, ultramafic, and sedimentary rocks, undivided) and PzZrqs (pelitic and quartzitic schist) of Wilson and others (1998) from the northeastern portion of the Ruby 1:250,000-scale quadrangle geologic map was further defined. The MSS image was first analyzed using spectral signatureEruption in an ice-filled caldera, Mount Veniaminof, Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1983
The more prominent of the two visible intracaldera cones of Mount Veniaminof went into eruption in early June 1983 and continued until early April 1984. Veniaminof is a 2,507-m-high composite cone having an 8 x 11-km summit caldera which formed 3,300-3,700 yr B.P. (Miller and Smith, 1977). The active 1.6x1.2-km cone protrudes 200 m through the glacial ice filling the caldera; it lies in a 60-m-lonGeologic setting, petrology, and age of Pliocene to Holocene volcanoes of the Stepovak Bay area, western Alaska Peninsula: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1988
Five volcanoes are situated north of Stepovak Bay on the western Alaska Peninsula; only one of these, Kupreanof volcano, had been reported prior to USGS reconnaissance geologic mapping of the area between 1982 and 1986. The volcanoes overlie sedimentary rocks of Eocene to late Miocene age and welded(?) tuff deposits of uncertain, but presumably late Tertiary, age. All five of the volcanoes are aliRadiometric age file for Alaska: A section in The United States Geological Survey in Alaska: Accomplishments during 1980
The Alaska radiometric age file of the Branch of Alaskan Geology is a computer-based compilation of radiometric dates from the state of Alaska and the western parts of the Yukon Territory and British Columbia. More than 1800 age determinations from over 250 references have been entered in the file. References date back to 1958 and include both published and unpublished sources. The file is the outDigital image processing techniques for detecting surface alteration - An application on the Alaska Peninsula: A section in The United States Geological Survey in Alaska: Accomplishments during 1983
The tectonic evolution of the Alaska Peninsula makes it a likely area for the discovery of significant mineral deposits. However, because of problems associated with remoteness and poor weather, little detailed mineral exploration work has been carried on there. This study focuses on using Landsat multispectral scanner data for the Port Moller, Stepovak Bay, and Simeon of Island Quadrangles to detLater Paleozoic and Early Jurassic fossil ages from the McHugh Complex: A section in Geologic studies in Alaska by the U.S. Geological Survey during 1985 Circular 978
Late Mississippian through Early Pennsylvanian and Early Jurassic microfossils were collected from the type locality of the McHugh Complex (Clark, 1973) along the Seward Highway southeast of Anchorage (fig. 36). Radiolarians collected indicate that same of the oceanic rocks in the McHugh Complex are Early Jurassic in age. Conodonts extracted from a conglomerate clast are of Late Mississippian throGeology and mineral resources of the Port Moller region, western Alaska Peninsula, Aleutian arc: A section in USGS research on mineral resources - 1989: Program and abstracts
Geologic mapping of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles was begun under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP) in 1983 . Two important mineral deposits are located in the Port Moller quadrangle; the Pyramid prospect is the largest copper porphyry system in the Aleutian Arc, and the Apollo Mine is the only gold mine to reach production statApparent episodicity of magmatic activity based on radiometric age determination: A section in The United States Geological Survey in Alaska: Accomplishments during 1980
Results of recent potassium-argon age studies in the Chignik region, Alaska, (Wilson, 1980; Wilson and others, 1982) have suggested a distinct episodicity in igneous activity during Tertiary time. To date work on the Aleutian magmatic arc indicates that plutonic activity took place along the present outer Pacific margin and in the northern Alaska-Aleutian Range batholith (Reed and Lanphere, 1973;Creation of a full color geologic map by computer: A case history from the Port Moller project resource assessment, Alaska Peninsula: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1988
Graphics programs on computers can facilitate the compilation and production of geologic maps, including full color maps of publication quality. This paper describes the application of two different programs, GSMAP and ARC/INFO, to the production of a geologic map of the Port Meller and adjacent 1:250,000-scale quadrangles on the Alaska Peninsula. GSMAP was used at first because of easy digitizing - Science
Alaska Resource Data File
The Alaska Resource Data File (ARDF) site provides descriptions of mines, prospects, and mineral occurrences for individual U.S. Geological Survey 1:250,000-scale quadrangles in Alaska.Geologic Map of Alaska
In January 2016, the U.S. Geological Survey released the first ever digital geologic map of Alaska. This map reflects more than a century of work and provides a visual context for the abundant mineral and energy resources found throughout the state. The map also is available to use in three different formats: a professional GIS database, a public interactive version via a web browser, and an... - News
- Maps
Filter Total Items: 28
Bedrock geologic map of the 15' Sleetmute A-2 quadrangle, southwestern Alaska
Twelve unnamed, bedrock stratigraphic units are recognized within the Sleetmute A-2 1:63,360-scale quadrangle of southwestern Alaska. These units range in age from late(?) Proterozoic through Devonian and can be divided into two distinct facies belts: (1) a southern facies of dominantly shallow-water platform carbonate and minor siliciclastic rocks (including Early Ordovician–Early Devonian platfoSurficial geologic map of the Dillingham quadrangle, southwestern Alaska
The geologic map of the Dillingham quadrangle in southwestern Alaska shows surficial unconsolidated deposits, many of which are alluvial or glacial in nature. The map area, part of Alaska that was largely not glaciated during the late Wisconsin glaciation, has a long history reflecting local and more distant glaciations. Late Wisconsin glacial deposits have limited extent in the eastern part of thReconnaissance surficial geologic map of the Taylor Mountains quadrangle, southwestern Alaska
This map and accompanying digital files are the result of the interpretation of aerial photographs from the 1950s as well as more modern imagery. The area, long considered a part of Alaska that was largely not glaciated (see Karlstrom, 1964; Coulter and others, 1965; or Péwé, 1975), actually has a long history reflecting local and more distant glaciations. An unpublished photogeologic map of the TReconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska
The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex (Kilbuck terrane) to Quaternary age mafic volcanic rocks of Nunivak Island. The map area encompasses much of the type area of the Togiak-Tikchik Complex. The geologic maps used to construct this compilation were, for the most part, reconnaissance studies done in the time period from the 1950sReconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska
The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex (Kilbuck terrane) to Quaternary age mafic volcanic rocks of Nunivak Island. The map area encompasses much of the type area of the Togiak-Tikchik Complex. The geologic maps used to construct this compilation were, for the most part, reconnaissance studies done in the time period from the 1950sReconnaissance geologic map of Kodiak Island and adjacent islands, Alaska
Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best availGeology of the Prince William Sound and Kenai Peninsula region, Alaska: Including the Kenai, Seldovia, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles
The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world’s largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska and Aleutian Ranges and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper RivGeology of the Prince William Sound and Kenai Peninsula region, Alaska: Including the Kenai, Seldovia, Blying Sound, Cordova, and Middleton Island 1:250,000-scale quadrangles
The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world’s largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska and Aleutian Ranges and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper RivGeologic map of the Cook Inlet region, Alaska, including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale quadrangles
In 1976, L.B. Magoon, W.L. Adkinson, and R.M. Egbert published a major geologic map of the Cook Inlet region, which has served well as a compilation of existing information and a guide for future research and mapping. The map in this report updates Magoon and others (1976) and incorporates new and additional mapping and interpretation. This map is also a revision of areas of overlap with the geoloGeologic Map of the Yukon-Koyukuk Basin, Alaska
This map and accompanying digital files represent part of a systematic effort to release geologic data for the United States in a uniform manner. All the geologic data in this series will be published as parts of the U.S. Geological Survey Data Series. The geologic data in this series have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale fiWorld heritage site - Bien du Patrimoine Mondial - Kluane/Wrangell-St. Elias/Glacier Bay/Tatshenshini-Alsek
The four parks depicted on this map make up a single World Heritage Site that covers 24.3 million acres. Together, they comprise the largest internationally protected land-based ecosystem on the planet. The United Nations Educational, Scientific and Cultural Organization (UNESCO) established the World Heritage Program in 1972 for the identification and protection of the world?s irreplaceable natur - Data
Geochemical and 40Ar/39Ar Analytical Data of Rocks from Glacier Bay National Park and Preserve
This data set contains major and trace element geochemical data and 40Ar/39Ar isotopic data and ages for rock samples collected during 2016 fieldwork in Glacier Bay National Park and Preserve. The plutonic rock samples were collected for radiometric age determinations to test for the presence of the Late Jurassic to Early Cretaceous (130-160 Ma) Saint Elias suite. The age analyses indicate that alU-Pb zircon data for: Cretaceous plutonic rocks of western Glacier Bay National Park and Preserve
In 2016, with National Park Service support, several previously undated plutons were sampled in Glacier Bay National Park and Preserve along the west side of Glacier Bay for age determinations. Geochronologic analyses were conducted to determine the ages of the plutonic rocks in the Glacier Bay area. Five samples were collected by Frederic Wilson (USGS Alaska Science Center), from Dundas Bay and G - Multimedia