This map is the result of field investigations by DGGS in 1997 and 1998. This geologic map and report supersede the previously released Public Data File 99-24B, Preliminary interpretive bedrock geologic map of the Healy A-6 Quadrangle, southcentral Alaska. The current map has been updated to include mapping of areas adjacent to the Healy A-6 Quadrangle, newly interpreted bedrock units based on newly acquired analytical, paleontologic, and Ar40/Ar39 data. Ages for the rock units were modified. Field investigations were part of a two-year mapping program to provide geologic ground truth for airborne geophysical surveys flown by DGGS in the Chulitna region of southcentral Alaska during 1996.

This map is the result of field investigations by DGGS in 1997 and 1998. This geologic map and report supersede the previously released Public Data File 99-24B, Preliminary interpretive bedrock geologic map of the Healy A-6 Quadrangle, southcentral Alaska. The current map has been updated to include mapping of areas adjacent to the Healy A-6 Quadrangle, newly interpreted bedrock units based on newly acquired analytical, paleontologic, and Ar40/Ar39 data. Ages for the rock units were modified. Field investigations were part of a two-year mapping program to provide geologic ground truth for airborne geophysical surveys flown by DGGS in the Chulitna region of southcentral Alaska during 1996.

Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km�equivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related information from these surface exposures, and how they relate to the area subsurface stratigraphy.

Geologic map geodatabase depicting the surficial geology of the central Brooks Range, Alaska. Including the 250k quadrangles of Ambler River, Bettles, Chandalar, Chandler Lake, Hughes, Howard Pass, Killik River, Phillip Smith Mountains, Survey Pass, and Wiseman. Database tables include geologic linework and geologic units.

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 the western half of the Wrangellia Terrane in the Anchorage, Gulkana, Healy, Mt. Hayes, Nabesna, and Talkeetna Mountains quadrangles of south-central 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 map shows the distribution of unconsolidated deposits and undifferentiated bedrock exposed at the surface in the Sagavanirktok A-3, A-4, B-3, B-4, and portions of the Sagavanirktok A-5 and B-5 quadrangles. Units were mapped by interpretation of stereo pairs of approximately 1:65,000-scale false-color infrared aerial photographs taken in June and August 1978, as well as 2.5 m and 10 m resolution SPOT imagery collected in 2009 and 2010. Fieldwork was completed in 2008.

During 2004 and 2005 DGGS Energy Section geologists, together with University of Alaska Fairbanks and USGS personnel, conducted 1:63,360-scale geologic mapping in the Siksikpuk River Area of the Chandler Lake B-4 and C-4 quadrangles in northern Alaska. This work was conducted as part of the USGS-funded STATEMAP project, part of the National Cooperative Geologic Mapping Program.

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 Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon 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.