Stevens, D.S.P. 20110630 map Report of Investigations RI 2011-4 Fairbanks, Alaska Alaska Division of Geological & Geophysical Surveys 1 sheet, scale 1:50,000 http://www.dggs.alaska.gov/pubs/id/22642 This surficial-geologic map shows the distribution of unconsolidated deposits and undifferentiated bedrock in the Faith Creek area in the Circle A-4, A-5, B-4, and B-5 quadrangles. This map was prepared principally by the interpretation of 1:63,360-scale, false-color, infrared aerial photographs taken in 1979 and 1981 and is locally verified by ground observations during field work in 2007. The purpose of this map is to show the distribution of unconsolidated geologic deposits and related features in the northern Fairbanks mining district. This project includes the following shapefiles: >NEF_border Polygon of boundary outline of the mapped area. >NEF_cirques Polylines showing headwalls of possible cirques. >NEF_geology Polygons of surficial-geologic map units. >NEF_photolinears Polylines showing photolinears. >NEF_pingos Points showing locations of pingos. 2007 ground condition Complete None planned -146.473760 -145.989693 65.409012 65.209562 ISO 19115 Topic Category geoscientificInformation ADGGS keywords Aerial Geology Alluvial Deposits Alluvial Fan Alluvium Colluvial Deposits Colluvium Complex Deposits Fluvial Geologic Map Geomorphology Glacial Deposits Glacial Drift Glacial Geology Landslide Landslide Deposit Man-Made Deposits Mining Placer Pingos Surficial Surficial Geologic Map Surficial Geology Terrace Till ADGGS keywords Chatanika River Circle Quadrangle Fairbanks Mining District Faith Creek Sourdough Camp Steese Highway ADGGS keywords Little Champion glaciation Prindle glaciation ADGGS keywords Holocene Cenozoic Pleistocene Quaternary This map is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below). The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product. State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS) mailing and physical

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Fairbanks Alaska 99709-3707 USA 907-451-5010 907-451-5050 Certainty in identification of the map units varies due to the scale and interpretive nature of the mapping. The geologic unit interpretations and boundaries presented in this report result from interpretation of nominal 1:65,000-scale aerial photographs taken in 1979 and 1981, investigative traverses throughout the map area, aerial reconnaissance via helicopter, and examination of road-cuts and river exposures. Surficial-geologic polygons and lines were edited and attributed using ArcGIS. This map has received two technical reviews by scientists familiar with the subject matter. We incorporated the reviewer's suggestions into the final draft. Polygon topology is present and clean on the original geospatial dataset. All polygon features were topologically validated using ArcGIS prior to export to shapefile format. The data set utilizes field observations and air photo interpretations to locate and characterize the geologic unit extent and features. It includes geospatial information about units traceable on air photos at a scale of ~1:65000 and/or in the field. Surficial-geologic map data has a horizontal positional accuracy dependent on: 1) the 1:65,000-scale (nominal) aerial photographs upon which the mapping was done, with an estimated potential error due to a pen line width of approximately 0.25 mm being equivalent to approximately 16.25 meters on the ground; and 2) the accuracy of the orthorectification of the aerial photographs, error magnitude highly variable and potentially large in areas of significant relief but generally has an RMS error of less than 4 pixels, equivalent to approximately 16.5 meters on the ground. Total potential horizontal error for surficial-geologic map features is therefore estimated to be up to 32.75 meters. Chapin, F.S., III Viereck, L.A. Adams, P.C. Van Cleve, Keith Fastie, C.L. Ott, R.A. Mann, Daniel, Johnson, J.F. 2006 book chapter New York Oxford University Press p. 100-120 Chapin, F.S., III (ed.) Oswood, M.W. (ed.) Van Cleve, Keith (ed.) Viereck, L.A. (ed.) Verbyla, D.L. (ed.) 2006 book chapter New York Oxford University Press paper 2006 publication date Chapin and others, 2006 Provided information on vegetation succession on floodplains. Kreig, R.A. Reger, R.D. 1982 document Geologic Report GR 66 Alaska Alaska Division of Geological & Geophysical Surveys 149 p. paper 1982 publication date Kreig and Reger, 1982 Provided information helpful to interpreting aerial photographs and relating the images to geologic processes. Mason, O.K. Beget, J.E. 1991 journal article Arctic and Alpine Research v. 23, no. 4 p. 392-403 paper 1991 publication date Mason and Beget, 1991 Provided information useful for interpreting depositional and flood processes on streams in interior Alaska. Rawlinson, S.E. Hickmott, D.R. 1987 document Miscellaneous Publication MP 29D Alaska Alaska Division of Geological & Geophysical Surveys p. 5.1-5.7, 4 sheets Smith, T.E. (ed.) Pessel, G.H. (ed.) Wiltse, M.A. (ed.) 1987 document Miscellaneous Publication MP 29D Alaska Alaska Division of Geological & Geophysical Surveys 63360 paper 1987 publication date Rawlinson and Hickmott, 1987 Provided information about previous surficial-geologic mapping in the area. Weber, F.R. Hamilton, T.D. 1984 document Professional Report PR 86 Alaska Alaska Division of Geological & Geophysical Surveys p. 42-48 Alaska Division of Geological & Geophysical Surveys (ed.) 1984 document Professional Report PR 86 Alaska Alaska Division of Geological & Geophysical Surveys paper 1984 publication date Weber and Hamilton, 1984 Provided information about the glacial history of interior Alaska. Fieldwork - Helicopter-supported fieldwork for surficial investigations, including traverses, road-cut investigations, and river exposures, was conducted for one week in June 2007 . Field notes and sediment samples were collected throughout the area for surficial investigations. Surficial mapping involved using Chapin and others (2006), Kreig and Reger (1982), Mason and Beget (1991), Rawlinson and Hickmott (1987), and Weber and Hamilton (1984) on a regular basis for checking glacial geology and general units. Observations were recorded on co-registered acetate overlays on 1:65,000-scale (nominal) color-infrared aerial photographs, and directly on 1:63,360-scale topographic base maps. Stations were located using air photos, topographic maps, and handheld GPS devices with location precision varying from approximately 3 to 15 meters. Chapin and others, 2006 Kreig and Reger, 1982 Mason and Beget, 1991 Rawlinson and Hickmott, 1987 Weber and Hamilton, 1984 200706 Geologic map compilation - Surficial-geologic information was interpreted using 1:65,000-scale (nominal) air-photo stereopairs, and compiled using permanent ink pen onto co-registered clear acetate overlays. 2007 Digitization of geologic map data - Digital files of the air photos were orthorectified using OrthoMapper photogrammetric software. The co-registered acetate overlays of geologic mapping were then orthorectified using the same equations applied to the air photos. Resultant orthorectified map data were then imported into ArcGIS and heads-up digitized into a personal geodatabase with validated topology. 2008 Revision of map data - Map data were revised in response to technical reviews by Richard Reger and Trent Hubbard. 201106 Metadata creation - Metadata for this map was compiled by De Anne Stevens. 201107 This is a vector data set that includes point, line, and polygon features. Vector Point GT-polygon composed of chains Complete chain Universal Transverse Mercator 6 0.999600 -147.00000 0 500000.0 0 coordinate pair 1 1 meters NEF_border Universal Transverse Mercator 6 0.999600 -147.00000 0 500000.0 0 coordinate pair 1 1 meters NEF_cirques Universal Transverse Mercator 6 0.999600 -147.00000 0 500000.0 0 coordinate pair 1 1 meters NEF_geology Universal Transverse Mercator 6 0.999600 -147.00000 0 500000.0 0 coordinate pair 1 1 meters NEF_photolinears Universal Transverse Mercator 6 0.999600 -147.00000 0 500000.0 0 coordinate pair 1 1 meters NEF_pingos North American Datum of 1927 Clarke 1866 6378206.4 294.9786982 NEF_border NEF_border.shp Polygon of boundary outline of the mapped area. This report. NEF_cirques NEF_cirques.shp Polylines showing headwalls of possible cirques. This report. NEF_geology NEF_geology.shp Polygons of surficial-geologic map units. This report. unit Geologic unit. This document. b EXPOSED BEDROCK Undifferentiated bedrock with essentially no cover This document. b' THINLY COVERED BEDROCK Undifferentiated bedrock that is covered by a thin (generally less than 1 m thick) veneer of colluvium, drift, undifferentiated glacial or glaciofluvial deposits, or combinations of these deposits; cover is sufficiently thin that planar bedrock structures, such as joints, foliation, and bedding or glacier-scoured bedrock subcrops are reflected at the ground surface by linear and curvilinear shallow troughs and bands of moist ground or hydrophilic vegetation This document. Qa ALLUVIUM, UNDIFFERENTIATED Elongate deposits of moderately to well-sorted, well-stratified, fluvial pebblecobble gravel, sand, and silt, with scattered to numerous boulders comprising channel and overbank deposits of generally small streams; medium to thick bedded, locally crossbedded, shows fining-upward cycles, and is locally auriferous; clasts generally rounded; extensive willowalder thickets grow on many Qa deposits in mature valley fills; unfrozen to discontinuously frozen with low to moderate ice contents; surface smooth to hummocky, except for local low scarps This document. Qaa ALLUVIUM IN ACTIVE CHANNELS Chiefly well-sorted and well-stratified layers and lenses of pebble gravel, sand, and silt with rare to scattered cobbles comprising river bars subject to recurrent inundation by modern streams every 5 yr or less (Chapin and others, 2006); mapped extent is a function of river level (stage) and reflects the transitory extent of exposed river bars at the time the photographs were taken; in braided and anastomosing reaches, active channels typically shift positions from year to year and present channel locations may differ from locations on the 1979 and 1981 photography; active channel alluvium underlies upper stream bank and active stream channels and includes point-bar and meander-scroll deposits; composed dominantly of gravel and sand where stream is braided and anastomosing, and sand and silt bars where meandering; prone to liquefaction where fine grained, unfrozen and saturated; where braided, subject to formation of extensive, thick, seasonal stream icings (aufeis); generally unfrozen, except seasonally frozen to depth of frost penetration; shallow water table This document. Qaf ALLUVIAL FAN DEPOSITS Fan-shaped deposits of poorly to moderately sorted gravel, sand, and silt with numerous cobbles and boulders in proximal zone deposited by streams where they emerge from mountain valleys onto lower-gradient surfaces; lithologies reflect bedrock of source area; in general, size of clasts decreases and degree of sorting increases downfan; typically mixed with debris-flow deposits in proximal part of fans; unfrozen to discontinuously frozen, except in fine-grained distal deposits, where permafrost may be shallow and continuous; ice contents low to moderate This document. Qai ALLUVIUM IN INACTIVE CHANNELS Elongate deposits of moderately to well-sorted, well-stratified, fluvial gravel, sand, and silt with scattered to numerous boulders forming modern floodplains and associated low terraces that are subject to flooding at least once or twice every century (Mason and Begét, 1991; Chapin and others, 2006); medium to thick bedded, locally crossbedded, shows fining-upward cycles, and may be locally auriferous; clasts generally rounded; may be covered by several meters of overbank silty sand and sandy gravel; may reflect former channels and flow regimes; may include more than one channel level; overbank sequences include flood-related features, like natural levees, crevasse-splays near channels, and fine-grained back-levee swale deposits farther from channels; lower surfaces may be flooded during periods of extremely high stream discharge; generally unfrozen in younger areas and discontinuously frozen in older areas with low to moderate ice contents; surface typically well vegetated, smooth to hummocky with local low scarps and bogs This document. Qat TERRACE ALLUVIUM, UNDIFFERENTIATED Elongate deposits of well-sorted, well-rounded to subrounded pebblecobble gravel and sand with trace to some silt and rare to numerous boulders forming stream terrace treads no longer subject to inundations by the stream that deposited the alluvium (Kreig and Reger, 1982); may include several levels and incorporate outwash alluvium; may be covered by several meters of organic sandy silt and silty sand; surface smooth, except for local low scarps; continuously to discontinuously frozen with low to moderate ice contents This document. Qat4 TERRACE ALLUVIUM OF YOUNGEST AGE Elongate deposits of well-sorted, well-rounded to subrounded pebblecobble gravel and sand with trace to some silt and rare to numerous boulders forming stream terrace treads no longer subject to inundations by the stream that deposited the alluvium (Kreig and Reger, 1982); may include several levels; may be covered by up to a meter of organic sandy silt and silty sand; upper surface typically only a few meters above modern stream level; surface smooth, except for local low scarps; continuously to discontinuously frozen with low to moderate ice contents This document. Qat3 TERRACE ALLUVIUM OF YOUNG-INTERMEDIATE AGE Elongate deposits of well-sorted, well-rounded to subrounded pebblecobble gravel and sand with trace to some silt and rare to numerous boulders forming stream terrace treads no longer subject to inundations by the stream that deposited the alluvium (Kreig and Reger, 1982); may include several levels; may be covered by several meters of organic sandy silt and silty sand; upper surface about 30-50 m above modern stream level along upper Chatanika River and lower Sourdough Creek; surface smooth, except for local low scarps; continuously to discontinuously frozen with low to moderate ice contents This document. Qat2 TERRACE ALLUVIUM OF INTERMEDIATE AGE Elongate deposits of well-sorted, well-rounded to subrounded pebblecobble gravel and sand with trace to some silt and rare to numerous boulders forming stream terrace treads no longer subject to inundations by the stream that deposited the alluvium (Kreig and Reger, 1982); includes several levels; distribution and elevation of deposits suggest unit may incorporate outwash alluvium of Little Champion or Prindle glaciations, or both, of Weber and Hamilton (1987); largest measured cobbles up to 54 cm diameter; upper surfaces of some granite cobbles strongly weathered and decomposed, while undersides remain sound; may be covered by several meters of organic sandy silt and silty sand; upper surface about 90 m above modern stream level along upper Chatanika River and lower Sourdough Creek; surface smooth, except for local low scarps; continuously to discontinuously frozen with low to moderate ice contents This document. Qat1 TERRACE ALLUVIUM OF OLDEST AGE Elongate deposits of well-sorted, well-rounded to subrounded pebblecobble gravel and sand with trace to some silt and rare to numerous boulders forming stream terrace treads no longer subject to inundations by the stream that deposited the alluvium (Kreig and Reger, 1982); includes several levels; distribution and elevation of deposits suggest unit probably incorporates outwash alluvium of Prindle glaciation or older of Weber and Hamilton (1987); commonly preserved as a thin veneer or gravel lag; upper surfaces of some granite cobbles strongly weathered and decomposed, while undersides remain sound; may be covered by several meters of organic sandy silt and silty sand; upper surface about 90-120 m above modern stream level along Faith Creek and about 180 m above modern stream level along upper Chatanika River; surface smooth, except for local low scarps; continuously to discontinuously frozen with low to moderate ice contents This document. Qat1? POSSIBLE TERRACE ALLUVIUM OF OLDEST AGE Possible upstream continuation of unit Qat1 into upper reaches of Faith Creek and upslope of unit Qat2 along the Chatanika River at the mouth s of Faith and Sourdough creeks; mapped primarily on the basis of subtle slope breaks and smooth surface morphology along valley walls; upper surface about 120-180 m above modern stream level along upper Chatanika River and 90-120 m above modern stream level along Faith Creek This document. Qc COLLUVIUM, UNDIFFERENTIATED Irregular, heterogeneous blankets, aprons, and fans of angular to subrounded rock fragments, gravel, sand, and silt that are left on slopes, slope bases, or high-level surfaces by residual weathering and complex, gravity-driven mass movements involving sliding, flowing, gelifluction, and frost creep of weathered bedrock and modified glacial drift; cobbles and boulders are scattered to numerous; on lower headwalls of cirques and upper walls of glaciated valleys includes talus aprons and steep fans built by snow avalanches and debris flows; may include thin residual deposits and lags of highly modified drift of ancient glaciations, particularly in the northern part of the map area; medium to thick bedded; generally unsorted to very poorly sorted; thickness is highly variable, with thickest deposits at the bases of slopes; locally washed by meltwater and slope runoff; surface disturbances, such as from excavation, may result in melting of permafrost and subsequent slumping and flowage; surface smooth, lobed, or terraced and, if deposit is thin, generally reflects morphologies of underlying materials; discontinuously to continuously frozen with low to moderate ice contents This document. Qcl? POSSIBLE LANDSLIDE DEPOSIT Unsorted, unstratified mixture of gravel, sand and silt derived from adjacent unconsolidated deposits and bedrock and deposited at the base of slope by near-surface to deep creeping, flowing, and sliding of failed bedrock and unconsolidated surficial deposits; surface slightly irregular to hummocky This document. Qcf MIXED COLLUVIUM AND ALLUVIUM Primarily fan-shaped or elongate, massive to poorly stratified, generally inorganic silt mixed with sandy angular to subangular pebble gravels derived from weathered bedrock uplands and deposited by debris flows and hyperconcentrated flows produced during brief, intense summer storms; colluvial processes dominate slightly over fluvial processes; contains numerous cobbles in glaciated terrain and angular to subangular, fresh to weathered rock fragments in weathered bedrock terrain; surface slightly irregular; discontinuously to continuously frozen with low to moderate ice contents This document. Qct TALUS DEPOSITS Fans and aprons of coarse, angular, unsorted, frost-rived rock fragments downslope of bedrock outcrops with trace to some gravel, sand, and silt deposited on steep bedrock slopes by rock falls, snow avalanches, free fall, tumbling, rolling, and sliding; surface steep, slightly irregular, and covered with numerous rock fragments, particularly in distal zones; includes debris-flow tongues; unfrozen to discontinuously frozen with low ice contents This document. Qlc LOWLAND COLLUVIUM Gravel, sand and silt derived from underlying or nearby bedrock and unconsolidated deposits and deposited in lowland areas adjacent to low-slope drainages primarily by mass-wasting processes; includes a component of primary and reworked eolian silt; overlies and incorporated into terrace deposits; surface smooth to gently sloping; discontinuously to continuously frozen with moderate to high ice contents This document. Qdlc DRIFT OF LITTLE CHAMPION AGE Till associated with the Little Champion glaciation of Weber and Hamilton (1984); subrounded cobbles and boulders and some angular chips of schist and quartzite in a yellowish-brown matrix of silty sand (Rawlinson and Hickmott, 1987) deposited by glacial ice and reworked by meltwater streams; primary surface morphology largely obliterated due to post-depositional modification by weathering and slope processes; mapped by photo-interpretation at a single site in study area, at head of Hope Creek tributary drainage This document. Qdp DRIFT OF PRINDLE AGE OR OLDER Till associated with the Prindle glaciation of Weber and Hamilton (1984) and possibly older glacial deposits; discontinuous to continuous sheets of heterogeneous pebble gravel with rare to numerous cobbles, boulders, and blocks up to 2 m in diameter in a brown matrix of sandy silt deposited directly from melting glacial ice and reworked by meltwater streams and mass-movement processes; generally thin, but locally up to 9.4 m thick; clasts generally subangular to subrounded; scattered angular pebbles; some small granite cobbles and pebbles are decomposing, but most are sound This document. Qdp? Possible DRIFT OF PRINDLE AGE OR OLDER Till associated with the Prindle glaciation of Weber and Hamilton (1984) and possibly older glacial deposits; discontinuous to continuous sheets of heterogeneous pebble gravel with rare to numerous cobbles, boulders, and blocks up to 2 m in diameter in a brown matrix of sandy silt deposited directly from melting glacial ice and reworked by meltwater streams and mass-movement processes; generally thin, but locally up to 9.4 m thick; clasts generally subangular to subrounded; scattered angular pebbles; some small granite cobbles and pebbles are decomposing, but most are sound This document. Qh CONSTRUCTION PAD Artificial fill of pebble-cobble gravel with trace to some sand and silt forming bases for DOT station; well to poorly sorted; surface smooth to irregular; extent based on distribution in August 1981 when the aerial photographs were taken This document. Qmt MINE TAILINGS Water-washed pebblecobble gravel with trace to some sand and silt piled in active or formerly active gravel pits, open-pit mines, and dredged areas; typically well sorted; surface smooth to irregular or forming symmetrical ridges and cones; unfrozen This document. NEF_photolinears NEF_photolinears.shp Polylines showing photolinears. This report. NEF_pingos NEF_pingos Points showing locations of pingos. This report. LAT Latitude of point. This document. 65.2 65.3 degrees LON Longitude of point. This document. -146.5 -146.0 degrees State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys mailing and physical

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Fairbanks AK 99709-3707 USA 907-451-5020 907-451-5050 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays Please view our web site (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible. The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requester or anyone else exceed the fee paid for the electronic service or product. Current publication is available on paper. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. http://www.dggs.alaska.gov/pubs/id/22642 SHP No compression applied http://www.dggs.alaska.gov/pubs/id/22642 Free download PDF No compression applied http://www.dggs.alaska.gov/pubs/id/22642 Free download DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media over the counter by mail, phone, fax, or email from the DGGS Fairbanks office. Turn around time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for a exact shipping amount. 20101004 Metadata manager mailing and physical

State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys

Fairbanks AK 99709-3707 USA 907-451-5020 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 If the user has modified this metadata file in any way, the user is obligated to describe the types of modifications the user has made. User specifically agrees not to misrepresent this metadata file, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. http://www.dggs.alaska.gov/metadata/dggs.ext dggs metadata extensions