Active and potentially active faults in or near the Alaska Highway corridor, Dot Lake to Tetlin Junction, Alaska

Carver, G. A. Bemis, S. P. Solie, D. N. Castonguay, S. R. Obermiller, K. E. 2010 Active and potentially active faults in or near the Alaska Highway corridor, Dot Lake to Tetlin Junction, Alaska tabular digital data Preliminary Interpretive Report PIR 2010-1 Fairbanks, Alaska - USA State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys 41 p. http://www.dggs.alaska.gov/pubs/pubs?reqtype=citation&ID=21121 In 2005, the Alaska Division of Geological & Geophysical Surveys initiated a multi-year geologic field study focused on a corridor centered along the Alaska Highway between Delta Junction and the Canada border. The purpose of this project is to provide geologic information relevant to a proposed Alaska-Canada natural gas pipeline and other future development in the corridor. The scope of this project includes identification of active faults and characterization of seismic hazards. During the 2008 field season the active fault studies were focused on the central part of the corridor between Dot Lake and Tetlin Junction. Field studies included helicopter and fixed-wing air reconnaissance augmented by interpretation of stereo air photos, remotely sensed images, ground reconnaissance, and field mapping. Detailed investigations were conducted where the reconnaissance identified lineaments indicative of Holocene surface faulting. In addition, detailed field studies were conducted of several lineaments identified in the published literature as possible active faults. The detailed studies included field mapping, topographic profiling, trenching, and 14C dating of surficial sediments associated with lineaments exhibiting characteristics of active faults. Two faults and a large fault-related anticline were found to have generated late Pleistocene and Holocene surface deformation in the Dot Lake-Tetlin Junction section of the corridor. These structures, the eastern part of the Dot "T" Johnson fault, the Cathedral Rapids fault, and the Giant Moletrack anticline, are active structures in the eastern part of the NFFTB. Detailed investigation of the Mansfield and Dennison Fork lineaments, identified as candidate active faults in the literature, produced conclusive evidence that they are not active faults. Detailed study of a third suspect lineament, the Bear Creek lineament, was inconclusive. This report is a part of ADGGS's Alaska Natural Gas Pipeline Geology and Geohazards project. The study was done in anticipation of the proposed natural gas pipeline along the Alaska Highway corridor. Recognition of potentially active faults is an important factor in design engineering of infrastructure. The publication consists of a report and a spreadsheet. The spreadsheet is a compilation of the information provided in Table 1 and in APPENDIX 1 of the report. This dataset consists of a single layer which is listed and described in detail under its own heading starting with "Entity_Type_Label." The layer is titled: >pir2010_1 14c ages for samples collected from trenches in 2008 2008 2010 ground condition Complete Unknown -144.0000 -142.50000 63.74115 62.16610 ISO 19115 Topic Category geoscientificInformation None Active Fault C14 Earthquake Faults Faulting Gasline Geologic Hazards Proposed Natural Gas Pipeline Strike-Slip Structural Geology Structure Tectonics Thrust Transportation Corridor None Alaska Highway Corridor Dot Lake Robertson River Tanacross Tanacross Quadrangle Taylor Highway Tetlin Tok Tok River None White River Ash Yukon-Tanana Upland Denali Fault None Holocene Quaternary Pleistocene 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

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Fairbanks AK 99709-3707 (907) 451-5010 (907) 451-5050 dggspubs@alaska.gov You may view our web site at http://www.dggs.alaska.gov 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 research was supported by 2009, and 2010 Alaska State Capital Improvement Projects funding.Additional Acknowledgments: Peter Haeussler (USGS) and Gordon Seitz (San Diego State University) for reviews of the Dot "T" Johnson trench III and Sears Creek trench. Valuable discussions with Richard D. Reger (Reger Geologic Consulting), Robert F. Swenson (ADGGS Director and State Geologist), and Rodney A. Combellick (ADGGS Deputy Director) are also acknowledged. We also appreciate suggestions and insight provided by the ADGGS bedrock-mapping group, Joe Andrews, Larry Freeman and Melanie Werdon. The report was reviewed by Richard Koehler. Adobe Acrobat Reader, and any text editor. Reger, R. D. Stevens, D. S. P. Solie, D. N. 2008 Surficial-geologic map, Alaska Highway Corridor, Delta Junction to Dot Lake, Alaska map Preliminary Interpretive Report PIR 2008-3A Fairbanks AK Alaska Division of Geological & Geophysical Surveys 2 sheets, scale 1:63,360 Reger, R. D. Solie, D. N. 2008 Engineering-geologic map, Alaska Highway Corridor, Delta Junction to Dot Lake, Alaska tabular digital data Preliminary Interpretive Report PIR 2008-3B Fairbanks AK Alaska Division of Geological & Geophysical Surveys 2 sheets, scale 1:63,360 Carver, G. A. Bemis, S. P. Solie, D. N. Obermiller, K. E. 2008 Active and potentially active faults in or near the Alaska Highway corridor, Delta Junction to Dot Lake, Alaska tabular digital data Preliminary Investigative Report PIR 2008-3D Fairbanks, AK Alaska Division of Geological & Geophysical Surveys p. 32 Reger, R. D. Hubbard, T. D. Carver, G. A. Unpublished material Surficial geology of the Alaska Highway corridor, Robertson River to Tetlin Junction, Alaska map Preliminary Investigative Report PIR 2009-6A Fairbanks, AK Alaska Division of Geological & Geophysical Surveys in press Hubbard, T. D. Reger, R. D. 2010 Engineering-geologic map of the Alaska Highway Corridor, Robertson River to Tetlin Junction, Alaska map Preliminary Interpretive Report PIR 2009-6B Fairbanks, AK Alaska Department of Geological & Geophysical Surveys 4 sheets, scale 1:63,360 Locations of trenches, core sites and profiles are given for the approximate mid-point of each feature. The radiocarbon samples were carefully extracted from trench walls and cores to minimize contamination. Samples were stored in the field in aluminum foil packets which were placed in labeled plastic bags after air-drying, and the dry samples transferred to labeled glass vials once they were out of the field. Before being sent to the laboratory for analyses, each sample was inspected through a binocular microscope, picked clean of mineral debris, and for some samples, individual plant macrofossils or charcoal grains were separated for analysis. Beta Analytic Radiocarbon Dating Laboratory in Miami Florida performed the radiocarbon age analyses on the 14C samples. Samples were pretreated using the acid/alkali/acid standard pretreatment protocol. All analysis was done using AMS methods and included 13C corrections. Quoted errors for laboratory ages represent 1 standard deviation statistics (68% probability) and are based on combined measurements of the sample, background, and modern reference standards. Measured 13C/12C ratios were calculated relative to the PDB-1 international standard and the radiocarbon years before present ("Lab Age") were normalized to -25 per mil. Laboratory ages were then calibrated using the OxCal v4.0 calibration program and the IntCal 04 calibration curve. All calibrated ages are reported as calibrated 2 sigma ranges before present (cal BP). The data in Appendix 1 report the method used, material type, paleoseismic significance, sample and lab numbers, lab age, 13C/12C ratios, and two-sigma calendar calibration result for each of the 20 radiocarbon samples. References for the calibration methods, as reported by Beta Analytic Inc. are: Stuiver, M., and van der Plicht, H., Radiocarbon, 1998, vol. 40, no. 3, p. xii-xiii. Stuiver, M. and others, Radiocarbon, 1998, vol. 40, no. 3, p. 1041-1083. Talma, A.S. and Vogel, J.C., Radiocarbon, 1993, vol. 35, no. 2, p. 317-322. not applicable All of the samples collected for dating were submitted for analysis and presented in this report. Locations of points recorded in the table were recorded using a Garmin GPS model 76CSx with a horizontal error of 4 meters or less. The locations are for approximate mid-point of each trench. Individual radiocarbon age samples in Appendix 1 are referred to their respective trenches and core sites whose locations are listed in Table 1. The spreadsheet distribution file is a compilation of Table 1 and Appendix 1. The actual location of each radiocarbon sample within the trench or core is shown in the trench logs and core logs in the figures of this report. Locations shown on the logs were determined using a metric tape, measuring distances from defined origins, to half-centimeter accuracy. Bemis, S. P. Wallace, W. K. 2007 Neotectonic framework of the north-central Alaska Range foothills book chapter Geological Society of America Special Paper 431 Special Paper 431 p. 549-572 Ridgeway, K. D. Trop, J. M. Glen, M. G. O'Neill, J. M. 2007 Tectonic growth of a collisional continental margin document Geological Society of America Special Paper Special Paper 431 editors paper 2007 publication date Bemis and Wallace, 2007 tectonic framework Bemis, S. P. 2004 Neotectonic framework of the north-central Alaska Range foothills document Fairbanks AK University of Alaska Fairbanks Masters Theses, 142 pages paper 2004 publication date Bemis thesis, 2004 tectonic framework Bemis, S. P. Weldon, R. J. Burns, P. A. C. 2005 Progress in characterizing active faults of the northern flank of the Alaska Range conference proceedings Geological Society of America Abstracts with Programs v. 37, no. 7, p.78 Geological Society of America Abstracts with Programs, vol.37, no. 7, p. 78 Annual Meeting, October 16, 2005 paper 2005 publication date Bemis, Weldon & Burns, 2005 Canteen fault abstract Burns, L. E. Fugro Airborne Surveys Stevens Exploration Management Corp. 2006 Line, grid and vector data, and plot files for the airborne geophysical survey of the Alaska Highway corridor, east-central Alaska vector digital data Geophysical Report GR 2006-6 Fairbanks AK Alaska Division of Geological & Geophysical Surveys DVD 2006 ground condition Burns, 2006 airborne geophysical data Carver, G. A. Plafker, George Metz, M.C. Cluff, Lloyd Slemmons, Burt Johnson, Elden Roddick, Jim Sorensen, Steve 2004 Surface rupture on the Denali fault interpreted from tree damage during the 1912 Delta River MW7.2-7.4 earthquake: Implications for the 2002 Denali fault earthquake slip distribution journal article Bulletin of the Seismological Society of America vol 94, no. 6B p. S58-S71 Rowe, C. A. Christensen, Douglas Carver, G. A. 2004 The 2002 Denali fault earthquake sequence document Bulletin of the Seismoloigcal Society of America Dedicated Issue v.94, no.6B paper 2002 ground condition Carver and others, 2004 Denali fault surface rupture Carver, G. A. Plafker, George Metz, M.C. Cluff, Lloyd Bemis, S.P. Roddick. Jim Redington, J. Sorensen, Steve 2006 Late Quaternary growth of thrust faults and associated folds in the eastern part of the Northern Foothills Fold and Thrust Belt, central Alaska Range, Alaska conference proceedings Alaska American Geophysical Union Chapman Conference on Active Tectonics and Seismic Potential of Alaska, May 11-14, 2006 paper 2006 publication date Carver and others, 2006 eastern Northern Foothills fold and thrust belt Matmon, Ari Schwartz, D. P. Haeussler, P. J. Finkel, R. Lienkaemper, J. J. Stenner, H. D. Dawson, T. E. 2006 Denali fault slip rates and Holocene-late Pleistocene kinematics of central Alaska journal article Geology v.34, no.8 p.645-648 paper 2006 publication date Matmon and others, 2006 Denali slip rates, central Alaska kinematics Page, R. A. Plafker, George Pulpan, Hans 1995 Block rotation in east-central Alaska: a framework for evaluating earthquake potential? journal article Geology v.23, no.7 p.629-632 paper 1995 publication date Page and others, 1995 block rotation in east-central Alaska Plafker, George Gilpin, L. M. Lahr, J. C. 1994 Neotectonic map of Alaska book chapter scale 1:2,500,000 Plafker, George Berg, H. C. 1994 The geology of Alaska document DNAG v.G-1 Boulder CO Geological Society of America editors 12 plates paper 1994 publication date Plafker and others, 1994 Neotectonic map of Alaska Reger, R. D. Stevens, D. S. P. Solie, D. N. 2008 Surficial-geologic map of the Alaska Highway corridor, Delta Junction to Dot Lake, Alaska map Preliminary Interpretive Report PIR 2008-3A Fairbanks AK Alaska Division of Geological & Geophysical Surveys 2 sheets, scale 1:63,360 digital database file 2008 publication date Reger and others, 2008 surficial geology map Carver, G. A. Bemis S. P. Solie, D. N. Obermiller, K. E. 2008 Active and potentially active faults in or near the Alaska Highway corridor, Delta Junction to Dot Lake, Alaska tabular digital data Preliminary Investigative Report PIR 2008-3D Fairbanks, AK Alaska Division of Geological & Geophysical Surveys p. 32 paper 2008 publication date Carver and others, 2008 potentially active faults Reger, R. D. Hubbard, T. D. Carver, G. A. Unpublished material Surficial geology of the Alaska Highway corridor, Robertson River to Tetlin Junction, Alaska tabular digital data Preliminary Investigative Report PIR 2009-6A Fairbanks, AK Alaska Division of Geological & Geophysical Surveys in press digital database file 2010 publication date Reger and others, in press surficial geology map Hubbard, T. D. Reger, R. D. 2010 Engineering-geologic map of the Alaska Highway Corridor, Robertson River to Tetlin Junction, Alaska tabular digital data Preliminary Interpretive Report PIR 2009-6B Fairbanks, AK Alaska Department of Geological & Geophysical Surveys 4 sheets, scale 1:63,360 digital database file 2010 publication date Hubbard and Reger, 2010 engineering - geologic map Initial reconnaissance - an initial interpretation of stereo air photos, remote sensed images, DEMs, and topographic maps of the corridor and surrounding regions was done prior to fieldwork. We also conducted a review of published and unpublished reports and geologic and geophysical survey maps to identify and locate lineaments and potentially active faults for further study. This initial phase was followed by helicopter reconnaissance of the corridor and adjacent regions with emphasis on potential faults and lineaments identified from the review of literature, air photos, remote sensed images, and maps. Based on the initial studies and the air reconnaissance, we identified lineaments and potentially active faults judged to warrant further studied in the field and selected sites for detailed investigation. Bemis and Wallace, 2007 Bemis thesis, 2004 Bemis, Weldon & Burns, 2005 Burns, 2006 Carver and others, 2004 Carver and others, 2006 Matmon and others, 2006 Page and others, 1995 Plafker and others, 1994 Reger and others, 2008 Reger and others, in press Carver and others, 2008 Hubbard and Reger, 2010 2008 Fieldwork - In July-August 2008, to further study specific sites identified in preliminary reconnaissance. The detailed investigations included geologic and geomorphic mapping, scarp profiling, measurement of scarp height and fault offset, and at selected sites, trenching and coring to develop paleoseismic information for active fault characterization 2008 Trenching - Trench sites were chosen to transect features suspected to be active faults, in order to expose a cross sectional view of faults and the most recent stratigraphy. At sites that were inaccessible to motorized excavation equipment we hand-dug the trenches. To facilitate field interpretation and logging we used nails to pin colored flagging along exposed contacts and faults on the cleaned trench walls. Logging of the trench walls was done by placing a grid of horizontal and vertical string lines over the exposed trench wall, and used this grid to accurately measure and transfer each feature to cross section Mylar. Each stratigraphic layer and feature of interest was described and locations of radiocarbon samples were recorded. Soil and sediment colors for each stratigraphic unit were defined using a Munsell Soil Color chart. Where possible, we collected radiocarbon samples from layers bounding faulting events to bracket the age of paleo-earthquakes interpreted from the stratigraphy. Upon completion, we backfilled the trenches, re-contoured the trench sites and replaced the natural vegetation. 2008 Labwork - The radiocarbon samples were carefully extracted to minimize contamination. Samples were stored in the field in aluminum foil bundles which were placed in labeled plastic bags after air-drying, and the dry samples transferred to labeled glass vials once they were out of the field. Before being sent to the laboratory for analyses, each sample was inspected through a binocular microscope, picked clean of mineral debris, and for some samples, individual plant macrofossils or charcoal grains were separated for analysis. Beta Analytic Radiocarbon Dating Laboratory in Miami Florida performed the radiocarbon age analyses on the 14C samples. 2008 Metadata creation - Metadata were assembled by T.D. Hubbard, G.C. Carver and R.A. Westbrook FGDC Standards using Metavist 1.2, DGGS 7.05, a data entry program for FGDC metadata with XML output. 2010 Point Universal Transverse Mercator 6 0.9996 -147.00000 0 500000.0 0 coordinate pair 0.0005 0.0005 meters pir2010_1 Universal Transverse Mercator 7 0.999600 -141.000000 0 500000.000000 0 coordinate pair 0.0005 0.0005 meters pir2010_1 North American Datum of 1927 Clarke 1866 6378206.4 294.978698 pir2010_1 pir2010_1.csv Geographic coordinates for trenches, core site and profiles and analytical results for radiocarbon samples Alaska Division of Geological & Geophysical Surveys Feature name of the the geologic feature in which the trench, core site or profile is located Alaska Division of Geological & Geophysical Surveys, refer to sources listed in the lineage section for specific information about the feature extent and nomenclature free text - names of geologic features Site name of the trench Alaska Division of Geological & Geophysical Surveys free text - name of the trench UTM Zone UTM zone in which trench, core site or profile is located Alaska Division of Geological & Geophysical Surveys 6V the UTM zone in which the sample was collected Alaska Division of Geological & Geophysical Surveys, US National Imagery and Mapping Agency 7V the UTM zone in which the sample was collected Alaska Division of Geological & Geophysical Surveys, US National Imagery and Mapping Agency UTM E Easting in UTM zone 6 or 7, NAD 27, Clark 1866 Alaska Division of Geological & Geophysical Surveys 379831 647503 meters UTM N Northing in UTM zone 6 or 7, NAD 27, Clark 1866 Alaska Division of Geological & Geophysical Surveys 6999311 7064849 meters Sample Number Sample number which is unique identifier for each radiocarbon sample, based on an abbreviation for trench followed by a consecutive number of sample collected from trench and depth in cm from surface. Alaska Division of Geological & Geophysical Surveys free text - unique sample number given to each radiocarbon sample analyzed. Location Location of sample within trench wall, as shown on gridded trench log, or in core. Alaska Division of Geological & Geophysical Surveys free text - description of location of each sample based on trench log Sample Material Type of carbon material dated Alaska Division of Geological & Geophysical Surveys Type of carbon analyzed (i.e., detrital charcoal, peaty material, wood, charcoal). Paleoseismic Significance Purpose for obtaining the age date; what constraints on timing the age imparts Alaska Division of Geological & Geophysical Surveys paleoseismic event or timing constrained by age date. Lab Number Unique identifying sample number assigned by the laboratory at Beta Analytic Inc. Beta Analytic Inc. Unique sample identifying numbers, preceded by "B" (e.g., B252298) Lab Age BP Radiocarbon years before present, ("present" being 1950). Quoted errors represent 1 standard deviation statistics. Alaska Division of Geological & Geophysical Surveys and Beta Analytic Inc. 70 10690 years 13C/12C 0/00 Measured ratio of 13C to 12C, calculated relative to the PCB-1 international standard. Alaska Division of Geological & Geophysical Surveys and Beta Analytic Inc. -28.2 -22.8 0/00 Age Cal BP Radiocarbon age calibrated to calendar years using the OxCal v4.0 calibration program and the IntCal 04 calibration curve. Ages reported as calibrated 2 sigma ranges before present. Alaska Division of Geological & Geophysical Surveys and Beta Analytic In. 0 12,840 years State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Natural Resource Technician mailing and physical

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Fairbanks AK 99709-3707 USA 907-451-5020 None available. 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. Preliminary Interpretive Report PIR 2010-1 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 pricing PDF 1.6 No compression applied http://www.dggs.alaska.gov/pubs/pubs?reqtype=citation&ID=21121 CSV None No compression applied http://www.dggs.alaska.gov/pubs/pubs?reqtype=citation&ID=21121 Digital files on CD-ROM are available for $10.00 (contact information below). Scanned images of these products may be viewed online or downloaded for free from the DGGS Web site. Order by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). The DGGS Web site (http://www.dggs.alaska.gov/pubs) has a list of electronic data available and an order form that can be printed. Payment accepted: Cash, check, money order, VISA, or MasterCard. Two weeks unless special arrangements are made and an express fee is paid. 20100820 State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Metadata Manager mailing and physical address

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