This data release is part of a 2016-2019 study on the geology, geochemistry and geochronology of ore systems in the eastern Yukon-Tanana Upland region, Alaska. Whole rock chemistry was conducted on 185 samples, mostly from Au prospects, with lesser samples from porphyry Cu prospects. Geographically, most samples are from gold prospects near the Pogo Au mine and east to Black Mountain in the Big Delta quadrangle. Fewer samples are from prospects in the Eagle and Tanacross Quadrangles. Samples were submitted to the USGS contract laboratory and analyzed for select trace elements and gold. Sixty elements were determined by inductively coupled plasma-optical emission spectroscopy-mass spectroscopy (ICP-OES-MS), sodium peroxide fusion (ICP-60). Gold was determined by lead fusion fire assay.

This data release is part of a 2016-2019 study on the geology, geochemistry and geochronology of ore systems in the eastern Yukon-Tanana Upland region, Alaska. Whole rock chemistry was conducted on 185 samples, mostly from Au prospects, with lesser samples from porphyry Cu prospects. Geographically, most samples are from gold prospects near the Pogo Au mine and east to Black Mountain in the Big Delta quadrangle. Fewer samples are from prospects in the Eagle and Tanacross Quadrangles. Samples were submitted to the USGS contract laboratory and analyzed for select trace elements and gold. Sixty elements were determined by inductively coupled plasma-optical emission spectroscopy-mass spectroscopy (ICP-OES-MS), sodium peroxide fusion (ICP-60). Gold was determined by lead fusion fire assay.

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. 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 northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska. 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.

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. 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 Haines area, Juneau and Skagway quadrangles, southeast Alaska. 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.

This report and digital data release presents 131 new geochemical analyses on historic U.S. Bureau of Mines (USBM) samples, including 86 rock and 42 heavy mineral concentrate (pan concentrate) samples, as well as 3 samples of indeterminate type. Some of these samples were originally collected by the USBM from the Ray River watershed, and the Kanuti and Hodzana Rivers uplands, central Alaska, and a portion of the samples were collected as part of the National Uranium Resource Evaluation. Historic USBM sample materials were retrieved by DGGS from the DGGS Geologic Materials Center (GMC), where the USBM samples were transferred as part of the federally funded Minerals Data and Information Rescue in Alaska (MDIRA) program in the late 1990s and early 2000s. The text and analytical data and tables associated with this report are being released in digital format as PDF files and .csv files. We provide analytical data, detection limits and, when available, the method documentation provided to us by the lab. We also provide the sample location in geographic coordinates, the sample material cited by the originating literature, a reference to the originating report, and the type of sample material that was obtained from the archive and sent to the lab.

This report and digital data release presents 209 new geochemical analyses on historic U.S. Bureau of Mines (USBM) samples, including 90 rock, 9 stream sediment, 14 soil, and 96 heavy mineral concentrate (pan concentrate) samples. These samples were originally collected by the USBM as part of their search for radioactive mineral deposits in the northern Darby Mountains, eastern Seward Peninsula, Alaska Historic USBM sample materials were retrieved by DGGS from the DGGS Geologic Materials Center (GMC), where the USBM samples were transferred as part of the federally funded Minerals Data and Information Rescue in Alaska (MDIRA) program in the late 1990s and early 2000s. The text and analytical data and tables associated with this report are being released in digital format as PDF files and .csv files. We provide analytical data, detection limits and, when available, the method documentation provided to us by the lab. We also provide the sample location in geographic coordinates, the sample material cited by the originating literature, a reference to the originating report, and the type of sample material that was obtained from the archive and sent to the lab.

This report and digital data release presents 90 new geochemical analyses on historic U.S. Bureau of Mines (USBM) samples, including 56 rock, 16 sediment, 5 soil, and 12 heavy mineral concentrate (pan concentrate) samples, as well as 1 sample of indeterminate type. Some of these samples were originally collected by the USBM as part of their mineral investigations in the Porcupine River drainage, northeastern Alaska, and a portion of the samples were collected as part of the National Uranium Resource Evaluation. Historic USBM sample materials were retrieved by DGGS from the DGGS Geologic Materials Center (GMC), where the USBM samples were transferred as part of the federally funded Minerals Data and Information Rescue in Alaska (MDIRA) program in the late 1990s and early 2000s. The text and analytical data and tables associated with this report are being released in digital format as PDF files and .csv files. We provide analytical data, detection limits and, when available, the method documentation provided to us by the lab. We also provide the sample location in geographic coordinates, the sample material cited by the originating literature, a reference to the originating report, and the type of sample material that was obtained from the archive and sent to the lab.

Personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted a reconnaissance rock sampling project from April 30 to May 4, 2012, to obtain modern, quantitative geochemical analyses to characterize select mafic-ultramafic rocks and one chalcopyrite-bearing quartz vein sample from Yellow Hill on Annette Island, in the Ketchikan Quadrangle, southeastern Alaska. Highlights of this sampling project include mafic-ultramafic rock samples with up to 0.079 ppm platinum (Pt) and 0.123 ppm palladium (Pd), and a quartz vein with 2.83 percent copper (Cu) and 0.155 ppm gold (Au).

Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys conducted reconnaissance stream-sediment and pan-concentrate sampling in the Melozitna Mining District, Tanana and Melozitna quadrangles, from July 25 to August 13, 2011. This helicopter-supported sampling project was part of a statewide assessment of Alaska's potential for rare-earth element (REE) mineralization, and was funded by the Rare Earth Elements and Strategic Minerals Assessment capital improvement project. During this field project, 32 stream sediment and 28 heavy-mineral pan concentrate samples were collected for geochemical analysis (geochemical trace elements and rare earth elements). An additional historic U.S. Bureau of Mines sample from the area was also analyzed as part of this report. Highlights of the DGGS sampling project include documenting new gold-bearing drainages and identifying several samples with high REE values.

This report and digital data release presents 326 new geochemical analyses on historic U.S. Bureau of Mines (USBM) samples, including 106 rock, 164 stream sediment, and 56 heavy mineral concentrate (pan concentrate) samples. These samples were originally collected by the USBM as part of a mineral-reconnaissance project in the Selawik Hills area of northwestern Alaska. Historic USBM sample materials were retrieved by DGGS from the DGGS Geologic Materials Center (GMC), where the USBM samples were transferred as part of the federally funded Minerals Data and Information Rescue in Alaska (MDIRA) program in the late 1990s and early 2000s. The text and analytical data and tables associated with this report are being released in digital format as PDF files and .csv files. We provide analytical data, detection limits and, when available, the method documentation provided to us by the lab. We also provide the sample location in geographic coordinates, the sample material cited by the originating literature, a reference to the originating report, and the type of sample material that was obtained from the archive and sent to the lab.