During the 2017 field season, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted geologic mapping and sampling of part of the Richardson mining district southeast of Fairbanks, Alaska. The project area is about 30 miles west of the Pogo gold mine and covers gold exploration activity at the Montecristo and Uncle Sam properties. This work aims to build an improved understanding of the area's geology and controls on gold mineralization for purposes of exploration targeting and mineral-resource assessment. The 260-square-mile map area lies between the Salcha River and Shaw Creek and is bounded by the Trans-Alaska Pipeline access road to the southwest. The area is characterized by forested, moderate-relief hills blanketed by vegetation, loess, and locally, sand dunes. Rock outcrop is less than one percent; consequently, the map interpretation relies heavily on the DGGS East Richardson airborne magnetic and electromagnetic survey as well as rocks collected from pits dug into rocky colluvial deposits below surficial loess or sand. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30676.

Scientific Investigations Map 2975, Geologic map of the Big Delta B-1 Quadrangle, east-central Alaska, provides detailed (1:63,360-scale) geologic mapping of the U.S. Geological Survey (USGS) Big Delta B-1 quadrangle. This data release is a conversion of the originating geospatial data published by the USGS and may include minor modifications necessary for schema compliance. The dataset contains geologic, structural, stratigraphic, and geochronologic data organized according to the GeMS and AK GeMS mapping schemas. The geodatabase and ESRI fonts and style files are available from the DGGS website: https://dggs.alaska.gov/pubs/id/23531.

Mineral Resources Section personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a geologic 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 geologic mapping. Specifically, this work provides geologic context for geophysical surveys conducted in 2006. Interpretation and synthesis of this data has been presented in professional and trade meetings. This report and associated geologic map data are preliminary, have not undergone rigorous peer review, and will be superseded by a subsequent Report of Investigations map and report that will be issued later in 2016. The objective of the eastern Bonnifield project is to produce a 1:50,000-scale geologic map to foster a better understanding of the area's geology and mineral potential. Although DGGS concentrated on mapping the Paleozoic metamorphic rocks that host the volcanogenic massive sulfide deposits (VMS) and Mesozoic igneous rocks associated with Au-Ag-As-Sb veins, we also studied the Tertiary sedimentary section, which could contain coal resources. The geologic map data are available in digital format as ESRI shapefiles.

Geologic map of the McGrath D-6 Quadrangle, Alaska, Professional Report 79, provides 1:63,360-scale geologic mapping of the McGrath D-6 Quadrangle, which lies on the eastern edge of the Kuskokwim Mountains, a maturely dissected upland of accordant rounded ridges and broad lowlands. Two highlands, the Candle Hills and Takotna Mountain, are surrounded by sediment-filled troughs of the Takotna, Tatalina, and Kuskokwim River valleys. Elevations range from 300 to 2,600 ft. This report is the result of 40 man-days of reconnaissance geologic mapping in 1977, 1978, and 1982. Bedrock exposures were mapped on foot and by boat. Four-fifths of the quadrangle is covered by Quaternary deposits, which have been subdivided on the basis of a photo-geologic reconnaissance and limited field checking. The report also includes detailed geologic, structural, stratigraphic, and geochronologic data. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/2253.

Report of Investigations 2004-1b, Bedrock geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska covers an approximately 435-square-mile area in the central Big Delta Quadrangle, Alaska. The bedrock geologic map was produced from fieldwork conducted during the months of June through August, 2000-2002, by mineral-resource personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) and the University of Alaska Fairbanks. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/3209.

This data file presents 40Ar/39Ar step-heating geochronology results for a granite sample from the Livengood mining district. The Livengood area is a historically productive placer mining area approximately 80 road miles north of Fairbanks, Alaska. This data is a component of a geologic map and accompanying report that synthesizes recently collected and previously published agency and industry geologic data in a 1:50,000-scale comprehensive geologic map to build a better understanding of the geology and mineral-resource potential of the Livengood area.

Bedrock geologic map of the northern Fairbanks mining district, Circle Quadrangle, Alaska, Preliminary Interpretive Report 2022-2, presents whole-rock trace-element geochemistry of Nb, Rb, Sr, Y, Zr for samples collected to support geologic mapping and mineral exploration in the northern Fairbanks mining district. The analytical data tables associated with this report are available through the Alaska Geochemistry database (https://maps.dggs.alaska.gov/geochem). For a direct link to this data release, see http://doi.org/10.14509/30891.