Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys carried out a geologic field survey, including mapping and sampling in the Moran area in the Tanana A-6 and B-6 quadrangles, and the Melozitna A-1, A-2, B-1, and B-2 quadrangles, Alaska, from June 17 to August 15, 2011. The fieldwork provides basic information critical to building an understanding of Alaska’s geology and is part of an integrated program of airborne geophysical surveys followed by geologic mapping. During 2011, 212 rock samples were collected for geochemical trace-element analysis (tables 1–3), 58 rock samples were collected for whole-rock (major- and minor-oxide and petrogenetically important trace elements) analyses, two samples were collected for analysis of non-carbonate carbon content, 439 polished rock slabs were analyzed for whole rock and petrogenetically important trace elements, and 26 samples were analyzed for rare earth elements.

Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys carried out a geological field survey, including mapping and sampling, in the eastern part of the Bonnifield mining district in the Fairbanks A-1 and A-2, and the Healy D-1 and D-2 quadrangles, Alaska, from June 16 through July 18, 2008. The fieldwork provides basic information critical to building an understanding of Alaska's geology and is part of an integrated program of airborne geophysical surveys followed by geological mapping. Specifically, this work provides geologic context for geophysical surveys conducted in 2006. To represent a typical lithology, igneous or possible meta-igneous samples were collected and analyzed for major- and minor-oxide and petrogenetically important trace elements as a supplement to previously published geochemical data. The analyses were used to determine composition of the samples as well as potential original tectonic setting. Radiometric age analyses from some of these rocks have been published. Interpretation and synthesis of this data has been presented in professional and trade meetings. The analytical tables associated with this data release are available in digital format as comma-separated value (CSV) files.

Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys carried out a geological field survey, including mapping and sampling in the eastern part of the Bonnifield mining district in the Fairbanks A-1, A-2, Healy D-1 and D-2 quadrangles, Alaska from June 16 to July 18, 2008. The fieldwork provides basic information critical to building an understanding of Alaska geology and is part of an integrated program of airborne geophysical surveys followed by geological mapping. During 2008, 242 rock samples were collected for geochemical trace-element analysis, 106 rock samples were collected for whole rock (major- and minor-oxide and petrogenetically important trace element) analyses, and 7 samples were collected for analysis of non-carbonate carbon content.

Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys carried out a geological field survey, including mapping and sampling near Livengood in the Livengood B-3 and B-4 quadrangles, Alaska from June 10 to June 30, 2010. The fieldwork provides basic information critical to building an understanding of Alaska’s geology and is part of an integrated program of airborne geophysical surveys followed by geological mapping. During 2010, 130 rock samples were collected for geochemical trace-element analysis, and 20 rock samples were collected for whole rock (major- and minor-oxide) analysis. Petrogenetically important trace elements for additional rock samples will be analyzed and published with the final map and report for this area.

Late Triassic mafic to ultramafic intrusions in the Wrangellia terrane are host to magmatic sulfide nickel-copper-cobalt and platinum-group element (PGE) mineralization. DGGS's mineral-resources group carried out a geologic mapping project in the eastern Denali Highway region between Watana Creek and Paxson from July 29 through August 7, 2015. This project is part of a multi-year effort focusing on improving the publicly available geological and geochemical data and assessing the mineral potential of the less-explored extension of the western Wrangellia terrane; other data resulting from this project include geophysical surveys and several geochemical datasets. This program of geologic mapping and rock sampling was conducted as part of the State of Alaska's Strategic and Critical Minerals Assessment project, an initiative designed to evaluate Alaska's potential for rare-earth elements, PGEs, and other similarly supply-challenged resources. Highlights of this project include identification, sampling, and characterization of a broad section of Wrangellia stratigraphy, including Late Triassic ultramafic and mafic intrusions thought to be a part of the Ni-Cu-Co-PGE- and Cu-Ag-mineralized Wrangellia large igneous province. This dataset includes four samples with high copper values (1.6 to 4.62 percent) and elevated silver values (10.15 to 18.25 ppm) and two samples have elevated copper (1,400 and 4,610 ppm); those samples are scattered throughout the area. Two samples from the Caribou Dome area show elevated platinum (0.113 and 0.101 ppm) and palladium (0.141 and 0.193 ppm). The analytical data tables associated with this report are being released in digital format as comma-delimited text (CSV) files.

The rock samples in this publication were collected in 2006 during geologic field mapping within the Council airborne geophysical survey tract. The analyses were acquired to aid interpretation and development of the geologic map and evaluation of the area's mineral potential. To further geologic understanding of the area, igneous and metamorphic rock samples were selected for whole-rock geochemical analysis. Unweathered or minimally weathered rock samples were preferentially selected for analysis. Non-carbonate carbon analyses were obtained to determine the percentage of graphite in metasedimentary rocks. To help evaluate the area's mineral resource potential, rock samples were selected for geochemical analysis; these rocks were either visibly mineralized, or had features that suggested the potential to be mineralized.

The mineral-resources group from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a geologic mapping project in the Talkeetna Mountains C-4, C-3, and B-4 quadrangles from July 23 through August 3, 2014. This project is a part of a multi-year project focusing on improving the publicly-available geological and geochemical data and assessing the mineral potential of the less-explored extension of the western Wrangellia terrane. This program of geologic mapping and rock sampling was conducted as part of the U.S. Geological Survey National Cooperative Geologic Mapping Program and the state of Alaska's Strategic Minerals Assessment project, an initiative designed to evaluate Alaska's potential for rare-earth elements, PGEs (platinum group elements), and other similarly supply-challenged resources. Highlights of this project include identification, sampling, and characterization of a broad section of the Wrangellia stratigraphy, including Late Triassic rocks of the Ni-Cu-Co-PGE- and Cu-Ag-mineralized Wrangellia large igneous province as well as modern geochemical characterizations of skarn, vein, and basalt-hosted Cu mineralization. This data set includes four samples with elevated gold, ranging from 0.5 to 0.875 ppm, with one of these samples also containing elevated Cu (1.18 percent). Twelve samples have elevated copper, ranging from 1000 to 7900 parts per million, and two samples contain a significant copper spike (13 and 19.65 percent) and elevated silver (42 and 48 parts per million). The analytical data tables associated with this report are being released in digital format as comma-delimited text (CSV) files.

Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a geological field survey, including mapping and sampling in the Chistochina mining district in the Mount Hayes A-2 and A-3 quadrangles, Alaska, from June 30 to July 15, 2009. The fieldwork provides basic information critical to building an understanding of Alaska's geology and is part of an integrated program of airborne geophysical surveys followed by geological mapping. During 2009, 57 rock samples were collected for geochemical trace-element analysis, 107 rock samples were collected for whole rock (major- and minor-oxide and petrogenetically important trace elements) analyses, and 2 samples were collected for analysis of non-carbonate carbon content. Additionally, 288 polished rock slabs were analyzed for whole rock and petrogenetically important trace elements. This report also contains geochemical trace-element analyses from the Mount Hayes A-2 Quadrangle, Alaska, for 359 rock samples collected by International Tower Hill Mines Ltd. (ITH) from July 2005 through August 2008 as part of the Chisna Project. These data were kindly donated to DGGS in 2009 to aid DGGS investigations.

Mineral-resources geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a helicopter-supported geological and geochemical resource assessment project in the Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles from July 29 through August 16, 2013. The objectives of this assessment were to improve the publicly-available geological, geophysical, and geochemical data in the area of known occurrences in the Mount Hayes Quadrangle, and to extend this coverage and any gained insight westward into the less-explored extension of the Wrangellia terrane. This program of stream-sediment, pan-concentrate, and rock sampling was conducted as part of the State's Strategic Minerals Assessment project, an initiative designed to evaluate Alaska's potential for rare-earth elements, PGEs, and other similarly supply-challenged resources. Highlights of this project include identification, sampling, and characterization of previously unmapped mafic to ultramafic intrusions and Nikolai Greenstone, modern geochemical characterizations of Ni-Cu-Co-PGE, skarn, vein, and basalt-hosted Cu mineralization, and documentation of regional-scale patterns in PGE enrichment across western Wrangellia. The analytical data tables associated with this report are being released in digital format as comma-delimited text (CSV) files.

Cook Inlet has been recognized as the second-largest petroleum province in Alaska, second only to the North Slope. The south-central Tyonek Quadrangle is an area of significant geologic interest because it is the only location in Cook Inlet where the entire producing stratigraphy of the basin is exposed on the surface. Additionally, this area encompasses the structural boundary between the forearc basin and its sediment source rocks. To better understand the petroleum system and the geologic relationships between the exhumed arc intrusive rocks and adjacent Cenozoic stratigraphy of the Cook Inlet forearc basin, during the summer of 2010 the Alaska Division of Geological & Geophysical Surveys conducted a federally-funded geologic field mapping project. As a part of this project DGGS collected 44 rock samples for geochemical analyses from Late Cretaceous and Paleogene intrusive and volcanic lithologies that compose part of the Alaska-Aleutian Range batholith and arc. Major-oxide, minor-oxide, and trace-element geochemical data presented here provide new information about the genesis and potential mineralization of igneous rocks in the western Neacola and southern Tordrillo mountains. The analytical data tables associated with this report are available in digital format as comma-separated value (CSV) files.