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At least 19 recordsLinked to original sources
USGS2021

Chemical analysis of archived stream-sediment samples, Alaska

Geochemical data are presented for more than 1,500 archived stream-sediment samples and accompanying quality control samples. The archived sediments were reanalyzed to improve the stream geochemical dataset for Alaska and to support ongoing U.S. Geological Survey (USGS) studies. Sediment samples were primarily from the USGS Mineral Resources Program’s sample archive in Denver, Colorado, but a few were from the Alaska Geological & Geophysical Surveys’ Geologic Materials Center in Anchorage, Alaska. All samples were submitted to the USGS contract laboratory, AGAT Laboratories, for analysis. All samples were analyzed using a 60-element analytical method involving fusion of the sample by sodium peroxide, dissolution of the fusion cake by nitric acid, and elemental analysis by inductively coupled plasma-optical emission spectroscopy and inductively coupled plasma-mass spectroscopy. Additionally, 106 samples from the Nixon Fork area were analyzed by a second multi-element method involving decomposition by a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids and the elemental analysis of the resulting solution by inductively coupled plasma-optical emission spectroscopy and inductively coupled plasma-mass spectroscopy. The latter method was used because the detection limit is lower for several elements including As, Cd, Pb, and Sb. Mercury concentrations in 296 samples from southeast Alaska were determined using a cold-vapor atomic absorption spectrometry method. The concentration data from the archived samples are presented along with concentration data from the standard reference material that was submitted with the samples.

Alaska↗
USGS1979

Selected Geological Survey, U.S. Bureau of Mines, and Alaska Division of Geological and Geophysical surveys reports and maps on Alaska released during 1978, indexed by quadrangle

This open—file report lists all Geological Survey, U.S. Bureau of Mines, and State of Alaska Division of Geological and Geophysical Surveys reports and maps on the geology, geophysics, and mineral and water resources of Alaska published or released to open files in 1978. They are listed by the quadrangles (scale 1:250,000) into which Alaska has been subdivided for topographic mapping (p. 4). As these three agencies also issued reports and maps on other subjects, the following lists are selected in the sense that such documents are not included. Most of the listed reports and maps bear a 1978 imprint date; a few with earlier imprint dates actually were not delivered until 1978. Reports that deal with regional tectonic hypotheses, regional syntheses, Alaska as a whole, or with areas that can not be identified with a specific quadrangle are listed under Alaska — General, as are statistical presentations, indexes, and the like. Reports and maps that deal with offshore areas not within quadrangle boundaries are listed under Offshore Areas. The Alaska — General and Offshore Areas lists appear before the alphabetically arranged quadrangle listings.

Alaska↗
USGS1977

Selected Geological Survey, U.S. Bureau of Mines, and Alaska Division of Geological and Geophysical Surveys reports and maps on Alaska released during 1976, indexed by quadrangle

This open-file report lists all Geological Survey, U.S. Bureau of Mines, and State of Alaska Division of Geological and Geophysical Surveys reports and maps on the geology, geophysics, and mineral and water resources of Alaska published or released to open files in 1976. They are listed by the quadrangles (scale 1:250,000) into which Alaska has been subdivided for topographic mapping (p. 3). As these three agencies also issued reports and maps on other subjects, the following lists are selected in the sense that such documents are not included. Most of the listed reports and maps bear a 1976 imprint date; a few with a 1975 imprint date actually were not delivered until 1976. Also included are a few that I overlooked when I prepared a similar index of reports and maps issued in 1975. Reports that deal with regional tectonic hypotheses, regional syntheses, Alaska as a whole, or with areas that can not be identified with a specific quadrangle are listed under Alaska - General, as are statistical presentations, indexes, and the like. Reports and maps that deal with offshore areas not within quadrangle boundaries are listed under Offshore Areas. The Alaska - General and Offshore Areas lists appear before the alphabetically arranged quadrangle listings. This index is intended to bring up to date the other indexes of this series, which are listed on p. 2.

Alaska↗
USGS1975

Geological Survey and selected U.S. Bureau of Mines and Alaska Division of Geological and Geophysical Surveys reports and maps on Alaska released during 1974, indexed by quadrangle

All Geological Survey reports and maps on Alaska published or released to open files during 1974 are listed by the quadrangle (scale 1:250,000) into which Alaska has been divided for topographic mapping (p. 2). Also listed are U.S. Bureau of Mines reports on the geology and mineral resources of Alaska, but not those dealing exclusively with other subjects such as economics. Alaska Division of Geological and Geophysical Surveys published reports on geology and mineral resources are listed, but those released to open files are not. This is because all open-file reports and maps were withdrawn in 1974 for revision, consolidation, or assignment of new identification numbers before possible reissue. At the time of preparation of this index I had received so few newly released open-file reports that I felt that including any of them might cause confusion to potential users because of possible duplication of titles or numbers.

Alaska↗
USGS1993

U.S.-Soviet Collaborative Geological and Geophysical Survey of the Mid-Atlantic Ridge near 31 degrees N, the Petrov Fracture Zone

Introduction In February 1989, the first formal U.S.-Soviet joint marine geologic-geophysical study in 10 years was undertaken along the Mid-Atlantic Ridge near 31°N on the 12th Cruise of the RN Akademik Boris Petrov of the Vernadsky Institute of Geochemistry (USSR Academy of Sciences, Moscow). This survey was initiated as part of the U.S.S.R.-U.S. cooperative research project "Mid-Atlantic Ridge Crest Processes" within the framework of the Soviet-U.S. bilateral Ocean Studies Agreement (Ostenso, 1989). U.S. scientists from the U.S. Geological Survey, University of Houston, and Woods Hole Oceanographic Institution participated in this program with Soviet scientists from the Vernadsky Institute of Geochemistry, Institute of Geology, and Schmidt Institute of Physics of the Earth, all institutes of the USSR Academy of Sciences in Moscow (Appendix 1 ). The ship departed from Rotterdam, Nederlands on February 2, 1989 and docked in Bridgetown, Barbados on February 28, 1989. A log of the ship's schedule during this cruise is given in Appendix 2. This study involved a limited multibeam-bathymetric, gravity, magnetic, and seismic- reflection survey. and dredging program of a short-offset transform fault named the Petrov Fracture Zone near 31 °N, located just north of the Atlantis Fracture Zone on the Mid Atlantic Ridge. A site survey at King's Trough in the northeast Atlantic for a MIR submersible program in June 1989 was originally planned as part of this program, but bad weather and the resultant poor quality geophysical data forced this work to be terminated after only one day. Nearly 6000 km of geophysical profile data and 13 dredge stations were completed during this cruise. A description of the geophysical systems aboard the RN Petrov is given in Appendices 3 and 4. All geophysical data were recorded on magnetic tape in data formats described in Appendix 5. Dredge locales and description summaries only are presented in Appendix 6. Detailed descriptions of dredge samples will be presented elsewhere. Operational plan for the studies on this cruise was developed as a cooperative effort between U.S. and Soviet scientists, who established jointly the basic objectives of the study. The U.S. scientists were given the responsibility for developing the detailed survey and dredge sampling plans. Dredge operations and basic geophysical systems operations were the responsibility of the Soviet personnel.

Open-File Report↗
USGS2015

Stratigraphic reconnaissance of the Middle Jurassic Red Glacier Formation, Tuxedni Group, at Red Glacier, Cook Inlet, Alaska

The Alaska Division of Geological & Geophysical Surveys (DGGS) and U.S. Geological Survey (USGS) are implementing ongoing programs to characterize the petroleum potential of Cook Inlet basin. Since 2009 this program has included work on the Mesozoic stratigraphy of lower Cook Inlet, including the Middle Jurassic Tuxedni Group between Tuxedni and Iniskin bays (LePain and others, 2013; Stanley and others, 2013; fig. 5-1). The basal unit in the group, the Red Glacier Formation (fig. 5-2), is thought to be the principal source rock for oil produced in upper Cook Inlet, and available geochemical data support this contention (Magoon and Anders, 1992; Magoon, 1994). Despite its economic significance very little has been published on the formation since Detterman and Hartsock’s (1966) seminal contribution on the geology of the Iniskin–Tuxedni area nearly 50 years ago. Consequently its stratigraphy, contact relations with bounding formations, and source rock characteristics are poorly known. During the 2014 field season, a nearly continuous stratigraphic section through the Red Glacier Formation in its type area at Red Glacier was located and measured to characterize sedimentary facies and to collect a suite of samples for analyses of biostratigraphy, Rock-Eval pyrolysis, vitrinite reflectance, and sandstone composition (fig. 5-3). The poorly known nature of the Red Glacier Formation is likely due to its remote location, steep terrain, and the fact that the type section is split into two segments that are more than 3 km apart. The lower 375 m segment of the formation is on the ridge between Red Glacier and Lateral Glacier and the upper 1,009 m segment is on the ridge between Red Glacier and Boulder Creek (fig. 5-3). Structural complications in the area add to the difficulty in understanding how these two segments fit together.

Alaska↗
USGS1972

Tectonic map of Liberia based on geophysical and geological surveys

Interpretation of the results of aeromagnetic, total-gamma radioactivity, and gravity surveys combined with geologic data for Western Liberia from White and Leo (1969) and other geologic information allows the construction of a tectonic map of Liberia. The map approximately delineates the boundaries between the Liberian (ca. 2700 m.y.) province in the northwestern two-thirds of the country, the Eburnean (ca. 2000 m.y.) province in the south-eastern one-third, and the Pan-African (ca. 550 m.y.) province in the coastal area of the northwestern two-thirds of the country. Rock follation and tectonic structural features trend northeastward in the Liberian province, east-northeastward to north-northeastward in the Eburnean province, and northwestward in the Pan-African age province. Linear residual magnetic anomailes 20-80 km wide and 200-600 gammas in amplitude and following the northeast structural trend typical of the Liberian age province cross the entire country and extend into Sierra Leone and Ivory Coast.

Open-File Report↗
USGS2017

Geospatial analysis identifies critical mineral-resource potential in Alaska

Alaska consists of more than 663,000 square miles (1,717,000 square kilometers) of land—more than a sixth of the total area of the United States—and large tracts of it have not been system atically studied or sampled for mineral- resource potential. Many regions of the State are known to have significant mineral-resource potential, and there are currently six operating mines in the State along with numerous active mineral exploration projects. The U.S. Geologi cal Survey and the Alaska Division of Geological & Geophysical Surveys have developed a new geospatial tool that integrates and analyzes publicly available databases of geologic information and estimates the mineral-resource potential for criti cal minerals, which was recently used to evaluate Alaska. The results of the analyses highlight areas that have known mineral deposits and also reveal areas that were not previously considered to be prospective for these deposit types. These results will inform land manage ment decisions by Federal, State, and private landholders, and will also help guide future exploration activities and scientific investigations in Alaska.

Alaska↗
USGS2015

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Tonsina area, Valdez Quadrangle, Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 128 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Tonsina area in the Chugach Mountains, Valdez quadrangle, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies

Alaska↗
USGS2015

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 105 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Zane Hills area in the Hughes and Shungnak quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Alaska↗
USGS2015

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Haines area, Juneau and Skagway quadrangles, southeast Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 212 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Chilkat, Klehini, Tsirku, and Takhin river drainages, as well as smaller drainages flowing into Chilkat and Chilkoot Inlets near Haines, Skagway Quadrangle, Southeast Alaska. Additionally some samples were also chosen from the Juneau gold belt, Juneau Quadrangle, Southeast Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Alaska↗
USGS2015

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Kougarok area, Bendeleben and Teller quadrangles, Seward Peninsula, Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 302 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Kougarok River drainage as well as smaller adjacent drainages in the Bendeleben and Teller quadrangles, Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Alaska↗
USGS2015

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Alaska↗
USGS2017

Reconnaissance sedimentology of selected tertiary exposures in the upland region bordering the Yukon Flats basin, east-central Alaska

This report summarizes reconnaissance sedimentologic and stratigraphic observations made during six days of helicopter-supported fieldwork in 2002 on Tertiary sedimentary rocks exposed in the upland region around the flanks of the Yukon Flats basin in east-central Alaska (fig. 1). This project was a cooperative effort between the Alaska Division of Geological & Geophysical Surveys (DGGS) and the U.S. Geological Survey (USGS) to investigate the geology of the basin in preparation for an assessment of the undiscovered, technically recoverable hydrocarbon resources (Stanley and others, 2004). Field observations and interpretations summarized in this report are reconnaissance level. At most, no more than a few hours were spent on the ground at any location. Measured sections included in this report are sketch sec- tions and thicknesses shown are approximate. Relatively detailed observations were made by the authors at only three locations, including The Mudbank (Hodzana River), Rampart (east bank of the Yukon River), and Bryant Creek (along the Tintina fault near the Canada border). These three locations are described first in relative detail, then followed by general descriptions of other locations.

Alaska↗
USGS2015

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 653 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering portions of the Inmachuk, Kugruk, Kiwalik, and Koyuk river drainages, Granite Mountain, and the northern Darby Mountains, located in the Bendeleben, Candle, Kotzebue, and Solomon quadrangles of eastern Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Alaska↗
USGS2014

Reanalysis of historical U.S. Geological Survey sediment samples for geochemical data from the western part of the Wrangellia terrane, Anchorage, Gulkana, Healy, Mt. Hayes, Nabesna, and Talkeetna Mountains quadrangles, Alaska

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. For the geochemical part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 1,682 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering the western half of the Wrangellia Terrane in the Anchorage, Gulkana, Healy, Mt. Hayes, Nabesna, and Talkeetna Mountains quadrangles of south-central Alaska (fig. 1). USGS was responsible for sample retrieval from the Denver warehouse through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

Alaska↗