C.G. Mull E.E. Harris P.R. Delaney R.F. Swenson 2009 vector digital data Preliminary Interpretive Report PIR 2009-5 Fairbanks, Alaska - USA State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys 40 pages, 1 sheet, 1:63,360 http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=19661 The Cobblestone Creek-May Creek area of the foothills of the Endicott Mountains is one of a series of areas selected for detailed mapping to document important structural and stratigraphic relationships at the mountain front of the east-central Brooks Range. The Cobblestone Creek-May Creek area is important in delineating the stratigraphic and structural relationships in this area because, unlike the adjacent valleys of the Itkillik and Nanushuk rivers, Cobblestone and May Creeks were not glaciated during the Pleistocene, and thus bedrock exposures are generally more continuous. Local field studies by the Alaska Division of Geological & Geophysical Surveys (DGGS) began in the area in 1982 and continued intermittently in conjunction with other field studies. In recent years, interest in hydrocarbon exploration in the Brooks Range foothills has increased considerably, resulting in an opportunity to compile previous studies as well as to carry out additional field studies to address specific structural and stratigraphic problems. In addition, ongoing mapping and structural and stratigraphic studies in the Siksikpuk River - Tiglukpuk Creek area to the west (Peapples and others, 2007) have resulted in some revised structural and stratigraphic concepts that have proven to be applicable to the Cobblestone Creek-May Creek map area and the adjacent Kanayut River map area to the west (Harris and others, in press). The layers listed below are present as ArcGIS shape files. Attribute information for the following layers (entities) is included in this metadata file under the "Entity_and_Attribution_Information" section. Each layer is listed and described in detail under its own heading starting "Entity_Type_Label." Basic unit information is also included in the geologic unit code set file "PIR2009-5_codeset.pdf". Layers include: >cob_attitude - strikes and dips of beds >cob_beds - beds traceable in outcrop or on air photos >cob_compgeo - geology polygons >cob_contacts - geologic contacts >cob_faults - fault traces >cob_folds - fold axial planes >cob_inferred - inferred geologic contacts >cob_kc - point locations of coquinoid limestone >cob_samples - sample locations (used only on appendix map) 2009 publication date Complete None planned -150.65249 -149.932958 68.75955 68.24027 None Contact Geology None May Creek Cobblestone Creek North Slope Brooks Range Chandler Lake Quadrangle None Tuluvak Formation Seabee Formation Nanushuk Formation Torok Formation Fortress Mountain Formation Cobblestone Member Unnamed Phosphatic-Manganiferous Shale Buchia Limestone Coquina Otuk Formation Okpikruak Formation Imnaitchiak Chert Siksikpuk Formation Lisburne Group Kayak Shale None Quaternary Cretaceous Jurassic Triassic Permian Pennsylvanian Mississippian This report, map, and/or dataset are available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below). Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. User specifically agrees not to misrepresent these datasets, 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. State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys GIS Data Manager/Cartographer mailing and physical

3354 College Road

Fairbanks AK 99709-3707 (907) 451-5029 (907) 451-5020 (907) 451-5050 dggspubs@dnr.state.ak.us You may view our web site at http://www.dggs.dnr.state.ak.us for the latest information on available data.Please e-mail your questions and data requests when possible since our web site and e-mail address will remain current even if our phone number and mailing address change. This Geologic Map was fundedby DGGS Energy Section. Geologic field investigations by: C.G. Mull (1982, 1985, 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1999, 2000, 2001); E.E. Harris (1985, 1999, 2000, 2001); Paige R. Peapples (2001); D.L. LePain, R.A. Kirkham, and R.R. Reifenstuhl (1999, 2000, 2001); Jerry Siok (1983, 1985); D.A. Bodnar (1983); K.E. Adams and M.L. Buckingham (1985); D.W. Houseknecht, C.J. Schenk, and T.J. Ryherd (2001); M.D. Myers (1989, 1999); M.T. Whalen and M.B. Mickey (2000).Digital cartography by Paige R. Delaney. ArcGIS 9.+, Adobe Acrobat Reader, and any text editor. Geologic point, line, and polygon data were determined visually using color infrared aerial photographs at a scale of approximately 1:63,360 and topographic maps at scales of 1:63,360 and larger. Feature attributes were checked by the geologists who conducted the field observations. To check attribute accuracy, a check plot was visually compared to the geologist's original compilation. Discrepancies between the digital geospatial dataset and the original analog or digital compilation were corrected as needed. The geologic interpretations presented in this report have undergone two technical reviews by geologists familiar with the subject of the report or geology of the map area. Reviewers' suggestions were incorporated into the final draft when deemed appropriate by the author. Polygon topology is present and clean on the originating geospatial dataset. All polygon features were were topologically validated using the ESRI ArcGIS 9.0 software prior to export to shape file format. The logical consistency of the point and line files has been visually checked but not systematically verified. This dataset includes geospatial information about beds traceable on air photos and/or in the field. The dataset displays: geologic units and contacts; inferred geologic contacts; fold and fault traces; strike, dip, and fold axis attitude; point locations of coquinoid limestone; manmade infrastructure such as airstrips, roads, etc.; sample locations; point elevations digitized from the raster map; and wells. Locations were determined in the field using raster images of topographic base maps and Garmin GPS units. The estimated positional error caluclated by the GPS unit was not recorded. Bedrock geologic map data also have a horizontal positional accuracy dependent on the "on-screen" method of digital cartography. Map error is induced by: (1) transferring map data from base topography to a Mylar compilation map, with an estimated potential error due to a pen line width of approximately 0.001 inches being equivalent to approximately 1.5 meters on the ground; (2) the digitizing RMS error (30 control points on a regular grid have an average RMS error of 14.0 meters on the ground; individual control point error ranges from 2.9 to 24.0 meters on the ground); and (3) the accuracy of the human operator digitizing the geologic line work from the topographic base map, with an estimated error due to a pen line width of approximately 0.001 inches being equivalent to approximately 1.5 meters on the ground. The average potential horizontal error for bedrock geologic map features is estimated to be approximately 15 meters. Patton, W.W., Jr. Tailleur, I.L. 1964 map Professional Paper P 0303-G Reston, VA United States Geological Survey p. 409-500, 3 sheets, scale 1:125,000 http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=3834 125000 paper 1964 ground condition Patton and Tailleur (1964) Published geologic mapping Pessel, G.H. Mull, C.G. 1964 map Unpublished mapping of Richfield Oil Corporation (Atlantic Richfield Company), by permission of Phillips Alaska, Inc. 250000 paper 1964 ground condition Pessel and Mull (1964) unpublished reconnaissance mapping Sonneman, H.S. Mull, C.G. 1972 map Exxon Company, USA unpublished mapping, by permission of Exxon Co., USA 125000 paper 1972 ground condition Sonneman and Mull (1972) unpublished reconnaissance mapping Geologic and structural information from published and unpublished mapping were compiled by C.G. Mull. Patton and Tailleur (1964) Pessel and Mull (1964) Sonneman and Mull (1972) 2002 Map Compilation - Geologic mapping took place during three-week field seasons during June-July 2004 and 2005. Mappers recorded observations in field notebooks and on the aerial photographs and topographic maps, predominantly at 1:63,360 scale. Bedrock mapping involved using aerial photographs and topographic maps on a daily basis for checking geologic contacts and units.All compilations were made by hand on stable mylar at 1:63,360 scale. Stations were located using aerial photographs, topographic maps, and altimeters. In most instances, GPS devices were used. Stations were also plotted by hand on stable mylar topographic bases and coordinates determined by digitizing. The bedrock geologic map was compiled using field notes from fieldwork process step (above), and all known geologic data from previous work in the quadrangle. Data were compiled on multiple layers of stable mylar at 1:63,360 scale. Relevant information from all mylar layers was compiled onto one stable mylar sheet with abundant control points. This mylar was then scanned and digitized. 2002 Digital Cartography - The compilation mylar was scanned as a high-resolution tiff file, which was imported into ArcGIS 9.1 and geographically registered in UTM coordinates (see spatial reference information below).Geologic polygons, linear features, and point data were digitized "on-screen" and attributed with appropriate supporting information.Editing and quality control checks took place at every process step.All final map layout and editing was done in Adobe Illustrator, Version CS2. 2009 Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_attitude Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_beds Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_compgeo Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_contacts Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_faults Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_folds Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_inferred Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_kc Universal Transverse Mercator 5 0.999600 -153.000 0.0 500000 0 coordinate pair 0.000064 0.000064 meters cob_samples D_Clarke_1866 Clarke 1866 6378206.4 294.978698 cob_beds cob_beds.shp Object type is vector and the entity values refer to beds traceable in outcrop or on air photos . Alaska Division of Geological & Geophysical Surveys cob_compgeo cob_compgeo.shp Object type is vector and the entity values refer to the unit name abbreviations for each specific polygon represented on the map. Alaska Division of Geological & Geophysical Surveys unit A unique three to four letter abbreviation given to each map unit represented on the map. Alaska Division of Geological & Geophysical Surveys PIR2009-5_codeset.pdf Alaska Division of Geological & Geophysical Surveys http://www.dggs.dnr.state.ak.us/metadata/PIR2009-5_codeset.pdf cob_contacts cob_contacts.shp Object type is vector and the entity values refer to to geologic map unit contacts. Alaska Division of Geological & Geophysical Surveys cob_faults cob_faults.shp Object type is vector and the entity values refer to various faults in the mapping area. Alaska Division of Geological & Geophysical Surveys fault_type Type of fault. Alaska Division of Geological & Geophysical Surveys alloc_con allochthon boundary, concealed Alaska Division of Geological & Geophysical Surveys alloc_con? allochthon boundary, concealed and queried Alaska Division of Geological & Geophysical Surveys alloch allochthon boundary thrust Alaska Division of Geological & Geophysical Surveys alloch? allochthon boundary thrust, queried Alaska Division of Geological & Geophysical Surveys alloch_con allochthon boundary thrust, concealed Alaska Division of Geological & Geophysical Surveys left_con? left-lateral fault, concealed, queried Alaska Division of Geological & Geophysical Surveys n_thru_con backthrust, concealed Alaska Division of Geological & Geophysical Surveys n_thrust? queried backthrust Alaska Division of Geological & Geophysical Surveys thrust thrust Alaska Division of Geological & Geophysical Surveys thrust?apx thrust fault, approximately located, queried Alaska Division of Geological & Geophysical Surveys thrust?con thrust fault, concealed, queried Alaska Division of Geological & Geophysical Surveys thrust_apx thrust fault, approximately located Alaska Division of Geological & Geophysical Surveys thrust_con thrust fault, concealed Alaska Division of Geological & Geophysical Surveys transverse trace of a transverse fault, relative motion unknown Alaska Division of Geological & Geophysical Surveys cob_folds cob_folds.shp Object type is vector and the entity values refer to fold axial traces. Alaska Division of Geological & Geophysical Surveys fold_type Type of fold. Alaska Division of Geological & Geophysical Surveys antconceal anticline, concealed Alaska Division of Geological & Geophysical Surveys anti axial trace of anticline Alaska Division of Geological & Geophysical Surveys antidash approximate anticline Alaska Division of Geological & Geophysical Surveys arrow arrow symbol to show plunge Alaska Division of Geological & Geophysical Surveys concealed trace of fault, concealed; relative motion unknown Alaska Division of Geological & Geophysical Surveys otanti overturned anticline Alaska Division of Geological & Geophysical Surveys syn syncline Alaska Division of Geological & Geophysical Surveys synconceal concealed syncline Alaska Division of Geological & Geophysical Surveys cob_inferred cob_inferred.shp Object type is vector and the entity values refer to inferred geologic contacts. Alaska Division of Geological & Geophysical Surveys cob_samples cob_samples.shp Object type is point and the entity values refer to sample locations (used only on appendix map in booklet as Figure A1) Alaska Division of Geological & Geophysical Surveys sample_type Type of sample. Alaska Division of Geological & Geophysical Surveys AFT Apatite fission track sample Alaska Division of Geological & Geophysical Surveys micro_chem sample for micropaleontology and geochem Alaska Division of Geological & Geophysical Surveys station_id Unique number assigned to each station. Alaska Division of Geological & Geophysical Surveys 00XXYY; 00=year, XX=Geologist's initials, YY= unique sample identifier. map_id Unique number assigned to each sample on the map. Alaska Division of Geological & Geophysical Surveys XX x latitude Alaska Division of Geological & Geophysical Surveys -150.0266899 -150.595395 degrees y longitude Alaska Division of Geological & Geophysical Surveys 68.3942 68.73016822 degrees cob_attitude cob_attitude.shp Object type is point and the entity values refer to strikes and dips of beds. Alaska Division of Geological & Geophysical Surveys strike The azimuth of the strike of the bed. Alaska Division of Geological & Geophysical Surveys 1 360 degrees dip The dip value of the bed, measured clockwise from strike. Alaska Division of Geological & Geophysical Surveys 0 90 degrees type_ Type of surface. Alaska Division of Geological & Geophysical Surveys appxbed approximate bedding surface Alaska Division of Geological & Geophysical Surveys appxotbed approximate overturned bedding surface Alaska Division of Geological & Geophysical Surveys bedding bedding surface Alaska Division of Geological & Geophysical Surveys horizontal horizontal bedding surface Alaska Division of Geological & Geophysical Surveys otbed overturned bed Alaska Division of Geological & Geophysical Surveys vertical vertical bedding surface - approximated Alaska Division of Geological & Geophysical Surveys vert vertical bedding - certain none cob_kc cob_kc.shp Object type is point and the entity values refer to point locations of coquinoid limestone. Alaska Division of Geological & Geophysical Surveys unit A unique three to four letter abbreviation given to each map unit represented on the map. Alaska Division of Geological & Geophysical Surveys kc coquinoid limestone Alaska Division of Geological & Geophysical Surveys State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Natural Resource Technician mailing and physical

3354 College Road

Fairbanks AK 99709-3707 USA 907-451-5020 None available. 907-451-5050 dggspubs@dnr.state.ak.us 8 am to 4:30 pm, Monday through Friday, except State holidays Please view our Web site (http://www.dggs.dnr.state.ak.us) for the latest information on available data. Please contact us using the e-mail address provided above when possible. Preliminary Interpretive Report 2009-5 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. Contact DGGS for current price. PDF 1.6 No compression applied http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=15901 Digital files on CD-ROM are available for $10.00 (contact information below). No fees charged for downloaded files. Order by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). The DGGS web site (http://www.dggs.dnr.state.ak.us/) has a list of electronic data available and an order form that can be printed. Payment accepted: Cash, check, money order, VISA, or MasterCard. Digital downloads: less than 30 minutes for most files. Offline CD/DVD-ROMs: 1-2 weeks unless special arrangements are made and an express fee is paid. It is suggested that MapInfo users import ESRI shape files (if provided) due to the possibility of data loss when importing Arc Export .e00 files. Please check the MapInfo Web site (http://www.mapinfo.com/) for the latest documentation on importing Arc Export and/or ESRI shape files. 20090601 20090601 State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Metadata Manager mailing and physical address

3354 College Road

Fairbanks AK 99709-3707 USA 907-451-5020 451-5000 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays. Please contact us through the e-mail address above whenever possible. FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 none If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys.