Active and Potentially Active Faults in Or Near the Alaska Highway Corridor, Dot Lake to Tetlin Junction, Alaska
Dates
Year
2010
Citation
Carver, Gary A., Bemis, Sean P., Solie, Diana N., Castonguay, Sammy R., and Obermiller, Kyle E., 2010, Active and Potentially Active Faults in Or Near the Alaska Highway Corridor, Dot Lake to Tetlin Junction, Alaska: Alaska Division of Geological & Geophysical Surveys, v. Preliminary Interpretive Report 2010-1, p. 42-42.
Summary
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. Identification of active faults and characterization of seismic hazards were included in the project. During the 2006 and 2007 field seasons, lineaments and geologic features indicative of possible youthful surface faulting in or near the western half of the corridor between Delta Junction and Dot Lake were identified and evaluated. Four of the lineaments were found [...]
Summary
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. Identification of active faults and characterization of seismic hazards were included in the project. During the 2006 and 2007 field seasons, lineaments and geologic features indicative of possible youthful surface faulting in or near the western half of the corridor between Delta Junction and Dot Lake were identified and evaluated. Four of the lineaments were found to be active (Holocene) faults. These are: (1) the Dot "T" Johnson fault, a thrust fault on the south side of the Tanana River valley along the base of the Alaska Range, (2) the Canteen fault, a strike-slip tear fault joining segments of the Dot "T" Johnson fault at a left step in the range front in the Little Gerstle River valley, (3) the Panoramic fault, also a left-lateral tear fault connecting the west end of the Dot "T" Johnson fault with the east end of the Donnelly Dome fault at a left step of the Alaska Range on the west flank of Granite Mountain, and (4) the Billy Creek fault, a northeast-trending left normal oblique fault north of the Tanana River valley in the Billy Creek drainage. The Dot "T" Johnson fault is interpreted to be an eastern extension of the Northern Foothills Fold and Thrust Belt (NFFTB), a system of active thrusts and fault-generated folds along the northern flank of the Alaska Range west of the Delta River. 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. ABSTRACT FROM AUTHOR]; Copyright of Preliminary Interpretive Report Series is the property of Alaska Division of Geological & Geophysical Surveys and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
