This data release presents the major and trace element chemistry of rock samples collected by the U.S. Geological Survey (USGS) from trenches, channel cuts, test pits, and surface exposures of the Dotson and I and L Zone rare earth element deposits at Bokan Mountain, located in the southern part of Prince of Wales Island, southeastern Alaska. Bokan Mountain was formed by an Early Jurassic peralkaline igneous complex that intruded into lower Paleozoic rocks of the Alexander terrane of southeast Alaska. The pluton and surrounding country rocks host numerous mineral deposits and occurrences, including heavy rare earth element (HREE)-rich pegmatites and felsic dikes, as well as mineral deposits rich in uranium, thorium, HREE, and fluorine. Recent exploration by Ucore Rare Metals Inc. (http://ucore.com/) at Bokan Mountain has focused on the Dotson and I and L Zones, which together form a 2.5-km-long, 50 m-wide zone of thin felsic dikes and pegmatites (each rarely more than 2-m-wide individually) that are enriched in rare earth elements (REE). Ucore Rare Metals has reported an indicated resource of 4.788 million metric tons of ore at 0.602 percent total REE oxides and an inferred resource of 1.050 million metric tons of ore at 0.603 percent total REE oxides, using a cutoff of 0.4 percent total REE oxides; about 40 percent of the total REE oxides in these dikes and pegmatites are the HREE (Ucore Rare Metals, 2020). There is also potential for the production of by-product Nb, Zr, and Ti. This data release provides the analytical results of 42 rock samples collected by the author during a site visit to Bokan Mountain in August 2014. The samples represent a complete transect along the entire length of the combined I and L and Dotson Zones from the margin of the pluton to tidewater in Kendrick Bay. They provide a measure of the REE abundances and their variation throughout the deposit as well as material for detailed isotopic and mineral chemistry studies (Taylor and others, 2016, 2017). The samples were analyzed for 57 major and trace elements using inductively coupled plasma-atomic emission spectrometry (ICP-AES), inductively coupled plasma-mass spectrometry (ICP-MS and ICP-MSREE), and inductively coupled plasma-optical emission spectrometry for zirconium (ICPOES). The samples were also analyzed for major elements using wavelength dispersive x-ray fluorescence spectrometry (WDXRF). This data set is provided for future use in geologic, exploration, and environmental background studies of the Dotson and I and L Zone deposits. References listed here provide geologic context and additional descriptions on the geologic features represented by the rock samples: Barker, J.C., and Van Gosen, B.S., 2012, Alaska's rare earth deposits and resource potential: Mining Engineering, v. 64, no. 1, p. 20-32. Dostal, J., Karl, S.M., Keppie, J.D., Kontak, D.J., Shellnutt, J.G., 2013, Bokan Mountain peralkaline granitic complex, Alexander terrane (southeastern Alaska)-Evidence for Early Jurassic rifting prior to accretion with North America: Canadian Journal of Earth Sciences, v. 50, 678-691. Dostal, Jaroslav, Kontak, D.J., and Karl, S.M., 2014, The Early Jurassic Bokan Mountain peralkaline granitic complex (southeastern Alaska)-Geochemistry, petrogenesis and rare-metal mineralization: Lithos, v. 202-203, p. 395-412. Dostal, Jaroslav, and Shellnutt, J.G., 2016, Origin of peralkaline granites of the Jurassic Bokan Mountain complex (southeastern Alaska) hosting rare metal mineralization: International Geology Review, v. 58, no. 1, p. 1-13. Long, K.R., Van Gosen, B.S., Foley, N.K., and Cordier, David, 2010, The principal rare earth elements deposits of the United States-A summary of domestic deposits and a global perspective: U.S. Geological Survey Scientific Investigations Report 2010-5220, p. 28-34. Available at http://pubs.usgs.gov/sir/2010/5220/. MacKevett, E.M., Jr., 1963, Geology and ore deposits of the Bokan Mountain uranium-thorium area, southeastern

This data set compiles the major and trace element chemistry of rock samples collected by the U.S. Geological Survey (USGS) at Bokan Mountain, located in the southern part of Prince of Wales Island, southeastern Alaska. Bokan Mountain was formed by an Early Jurassic peralkaline igneous complex that intruded into lower Paleozoic rocks of the Alexander terrane of southeast Alaska. The pluton and surrounding country rocks host numerous mineral deposits and occurrences, including heavy rare earth element (HREE)-rich pegmatites and felsic dikes, as well as mineral deposits rich in uranium, thorium, HREE, and fluorine. The Ross-Adams mine on Bokan Mountain exploited a uranium-thorium deposit intermittently from the late 1950s to 1971, and remains the only uranium producer in Alaska. Recent exploration by Ucore Rare Metals Inc. (http://ucore.com/) at Bokan Mountain has focused on the Dotson and I and L Zones, which together form a 2.5-km-long, 50 m-wide zone of thin felsic dikes and pegmatites (each rarely more than 2-m-wide) that are enriched in rare earth elements (REE). Ucore Rare Metals has reported an inferred resource for the combined zones as 5.275 million metric tons of ore at 0.654 percent total REE oxides, using a cutoff of 0.4 percent total REE oxides; about 40 percent of the total REE oxides in these dikes and pegmatites are the HREE (http://ucore.com/Ucore_43-101.pdf). This data release provides the analytical results of 153 rock hand samples collected by USGS geologists during site visits to Bokan Mountain in 2010, 2011, and field studies during 2014. The samples represent a variety of rock types associated with the Bokan Mountain igneous complex, including mineral deposits, prospects and occurrences, along with examples of unaltered intrusions of the pluton. The samples were analyzed for 55 major and trace elements using inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS) and also analyzed for major elements using wavelength dispersive x-ray fluorescence spectrometry (WDXRF). This data set is provided for future use in geologic, exploration, and environmental background studies of Bokan Mountain and its mineral deposits.

This data release presents the major and trace element chemistry of rock samples collected by the U.S. Geological Survey (USGS) from surface exposures of the Dora Bay igneous complex (DBIC), located in the southern part of Prince of Wales Island, southeastern Alaska. The DBIC is Early Jurassic in age (Bala and others, 2014) and is U-Th-heavy rare earth element (HREE)-enriched like the Bokan Mountain intrusive complex 30 km to the south (Philpotts and others 1998; Dostal and others, 2011; Taylor and others, 2016; 2017). However, the DBIC is significantly less-well-mineralized and is under-explored due to complicated private land status issues. HREE-enriched eudialyte-bearing pegmatites and felsic dikes have been discovered in numerous places within and along the margins of the pluton and extending up to 1 km into the country rocks as well as molybdenite and iron oxide mineral occurrences at its margins (Barker and Mardock, 1990; Philpotts and others, 1993; Taylor and others, 2014). Uncertainty of global REE supply and the subsequent spike in prices in 2008 resulted in renewed exploration at the DBIC by Avalon in 2010 and Sealaska Native Corporation in 2014-2015 (Buckley and Taylor, 2014). The DBIC was included in recent studies by the USGS Mineral Resources Program as part of an effort to understand the distribution of REE resources in the United States. This data release provides the analytical results of 54 rock samples collected by the authors during a site visit to the DBIC in June-July 2015. The samples represent transects along the major exposed ridgelines and outcrops within the complex. They provide a measure of the REE abundances and their variation throughout the complex as well as material for detailed isotopic and mineral chemistry studies. The samples were analyzed for 60 major and trace elements by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS)after a sodium fusion digestion and for major elements using wavelength dispersive x-ray fluorescence spectrometry (WDXRF). This data set is provided for future use in geologic, exploration, and environmental background studies of the DBIC. References listed here provide geologic context and additional descriptions on the geologic features represented by the rock samples: Bala, S.A., Holm-Denoma, C.S., Neymark, L.A., Taylor, C.D., Pietruszka, A.J., and Driscoll, R.L., 2014, U-Pb zircon ages and mineralogy of the Dora Bay intrusive complex and heavy REE-bearing pegmatite dikes: Geological Society of America Abstracts with Programs, v. 46, no. 6, p. 782, Abstract No. 324-11. Barker, J.C., and Mardock, Cheryl, 1990, Rare-earth element- and yttrium-bearing pegmatite dikes near Dora Bay, southern Prince of Wales Island: U.S. Bureau of Mines Open-File Report 19-90, 41 p. Barker, J.C., and Van Gosen, B.S., 2012, Alaska's rare earth deposits and resource potential: Mining Engineering, v. 64, no. 1, p. 20-32. Buckley, Steve, and Taylor, Cliff, 2014, Mineral potential on Sealaska Corporation Lands, southeast Alaska: Alaska Miner’s Association Biennial Conference on Alaskan Mining, Anchorage, Nov. 3–7, Abstracts of Papers, p. x. Dostal, J., Kontak, D.J., Hanley, J., and Owen, V. 2011. Geological investigation of rare earth element and uranium deposits of the Bokan Mountain Complex, Prince of Wales Island, Southeastern Alaska. U.S. Geological Survey Mineral Resources External Research Report G09AP00039, p. 122. Long, K.R., Van Gosen, B.S., Foley, N.K., and Cordier, David, 2010, The principal rare earth elements deposits of the United States-A summary of domestic deposits and a global perspective: U.S. Geological Survey Scientific Investigations Report 2010-5220, p. 28-34. Available at http://pubs.usgs.gov/sir/2010/5220/. Philpotts, J., Taylor, C.D., Evans, J., and Emsbo, P., 1993, Newly discovered molybdenite occurrences at Dora Bay, Prince of Wales Island, southeast Alaska, and preliminary scanning electron

This data release presents the major and trace element chemistry of rock samples collected by the U.S. Geological Survey (USGS) from surface exposures of the Dora Bay igneous complex (DBIC), located in the southern part of Prince of Wales Island, southeastern Alaska. The DBIC is Early Jurassic in age (Bala and others, 2014) and is U-Th-heavy rare earth element (HREE)-enriched like the Bokan Mountain intrusive complex 30 km to the south (Philpotts and others 1998; Dostal and others, 2011; Taylor and others, 2016; 2017). However, the DBIC is significantly less-well-mineralized and is under-explored due to complicated private land status issues. HREE-enriched eudialyte-bearing pegmatites and felsic dikes have been discovered in numerous places within and along the margins of the pluton and extending up to 1 km into the country rocks as well as molybdenite and iron oxide mineral occurrences at its margins (Barker and Mardock, 1990; Philpotts and others, 1993; Taylor and others, 2014). Uncertainty of global REE supply and the subsequent spike in prices in 2008 resulted in renewed exploration at the DBIC by Avalon in 2010 and Sealaska Native Corporation in 2014-2015 (Buckley and Taylor, 2014). The DBIC was included in recent studies by the USGS Mineral Resources Program as part of an effort to understand the distribution of REE resources in the United States. This data release provides the analytical results of 54 rock samples collected by the authors during a site visit to the DBIC in June-July 2015. The samples represent transects along the major exposed ridgelines and outcrops within the complex. They provide a measure of the REE abundances and their variation throughout the complex as well as material for detailed isotopic and mineral chemistry studies. The samples were analyzed for 60 major and trace elements by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS)after a sodium fusion digestion and for major elements using wavelength dispersive x-ray fluorescence spectrometry (WDXRF). This data set is provided for future use in geologic, exploration, and environmental background studies of the DBIC. References listed here provide geologic context and additional descriptions on the geologic features represented by the rock samples: Bala, S.A., Holm-Denoma, C.S., Neymark, L.A., Taylor, C.D., Pietruszka, A.J., and Driscoll, R.L., 2014, U-Pb zircon ages and mineralogy of the Dora Bay intrusive complex and heavy REE-bearing pegmatite dikes: Geological Society of America Abstracts with Programs, v. 46, no. 6, p. 782, Abstract No. 324-11. Barker, J.C., and Mardock, Cheryl, 1990, Rare-earth element- and yttrium-bearing pegmatite dikes near Dora Bay, southern Prince of Wales Island: U.S. Bureau of Mines Open-File Report 19-90, 41 p. Barker, J.C., and Van Gosen, B.S., 2012, Alaska's rare earth deposits and resource potential: Mining Engineering, v. 64, no. 1, p. 20-32. Buckley, Steve, and Taylor, Cliff, 2014, Mineral potential on Sealaska Corporation Lands, southeast Alaska: Alaska Miner’s Association Biennial Conference on Alaskan Mining, Anchorage, Nov. 3–7, Abstracts of Papers, p. x. Dostal, J., Kontak, D.J., Hanley, J., and Owen, V. 2011. Geological investigation of rare earth element and uranium deposits of the Bokan Mountain Complex, Prince of Wales Island, Southeastern Alaska. U.S. Geological Survey Mineral Resources External Research Report G09AP00039, p. 122. Long, K.R., Van Gosen, B.S., Foley, N.K., and Cordier, David, 2010, The principal rare earth elements deposits of the United States-A summary of domestic deposits and a global perspective: U.S. Geological Survey Scientific Investigations Report 2010-5220, p. 28-34. Available at http://pubs.usgs.gov/sir/2010/5220/. Philpotts, J., Taylor, C.D., Evans, J., and Emsbo, P., 1993, Newly discovered molybdenite occurrences at Dora Bay, Prince of Wales Island, southeast Alaska, and preliminary scanning electron

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.

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).

Geochemical data from samples collected in 2022 for the Mount Harper geologic mapping project, Big Delta, Mount Hayes, and Eagle quadrangles, Alaska, Raw Data File 2023-24, presents whole-rock and major- and trace-element geochemistry of rock samples collected to support geologic mapping and mineral exploration in the Mount Harper area of the Melozitna mining district. During the 2022 field season, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted 1:100,000-scale bedrock geologic mapping of ~3,100 mi2 (~8,000 km2) within the Big Delta, Mount Hayes, and Eagle quadrangles. This project aims to produce more detailed and modern geologic maps and supporting datasets to promote mineral resource exploration in eastern Interior Alaska. The project area includes known gold (Au) mineralization, recently explored in the Richardson mining district, including the SAM project and the nearby Democrat Lode and associated prospects, and in the Goodpaster mining district at the LMS and Healy intrusion-related gold prospects. The Mount Harper area hosts a cluster of molybdenum (Mo) and tungsten (W) prospects, including porphyry Mo and W skarn styles, both of which have had industry interest over the decades. Ultramafic rocks occur in the South Fork and Volkmar river drainages; these bodies have an as-yet poorly understood potential to host platinum group elements (PGE), chrome (Cr), cobalt (Co), and nickel (Ni) resources. The DGGS map area includes a section of pre-Mississippian to Permian metasedimentary and metaigneous rocks and Triassic to Paleogene intrusive and volcanic rocks. Major- and trace-element geochemistry for these rocks was analyzed to further our understanding of the resources in the area, including distinguishing between igneous and sedimentary protoliths for metamorphic rocks and characterizing and differentiating Mesozoic and Cenozoic magmatic events in the area. Highlights of this geochemical report include sampling of the Healy and LMS projects and multiple prospects on Mount Harper and elsewhere in the map area. Sample 22Z336, collected south of the Brink prospect, yielded 1.52 ppm Au and 500 ppm W. A few samples collected at the LMS prospect yielded elevated silver (Ag) concentrations (for example, sample 22Z409 yielded up to 12.95 ppm). Additionally, sample 22Z406 yielded 1.48 ppm Au, 7.65 ppm Ag, and 1,787 ppm arsenic (As). Samples collected at Larsen Ridge/Lucky 13 prospect near the top of Mount Harper yielded high Ag and W values. For example, 22Z271 (a massive quartz vein) yielded 18.87 ppm Ag and 1,100 ppm W, 22TJN157 (a skarn) yielded 5.75 ppm Ag, 2,348 ppm copper, 4,422 ppm manganese (Mn), and 600 ppm W, and 22Z270 (a granite) yielded 2,356 ppm Mo and 200 ppm W. The Richardson mining district has been previously sampled by DGGS. This data file is released as a Raw Data File with an open end-user license. The data are available from the DGGS website: http://doi.org/10.14509/31089.

Major oxide and trace element analyses for rock samples from the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska, Raw Data File 2024-18, presents whole-rock and major- and trace-element geochemistry of rock samples collected to support geologic mapping in portions of the Skagway A-1, A-2, B-1, B-2, and B-3 15-minute quadrangles, an area of approximately 300 square miles. On December 2, 2020, a landslide triggered by an atmospheric river weather phenomenon at Beach Road in Haines, Alaska, claimed two lives. Numerous debris flows were also recorded around town during the same rain event, especially along Lutak Spur Road. As a response, the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project's goal is to create an updated 1:50,000-scale geologic map in paper and digital GIS formats. A comprehensive, detailed map constructed using modern analytical methods is critical to help land managers and residents make informed decisions when planning future development and evaluating risks to infrastructure. During July 2022, May 2023, and August 2023, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted fieldwork supporting surficial and bedrock mapping (Truskowski and others, 2024). This data file is released as a Raw Data File with an open end-user license. The data are available from the DGGS website: http://doi.org/10.14509/31286.