Geologic map of the Umiat-Gubik area, central North Slope, Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
Geologic map of the Umiat-Gubik area, central North Slope, Alaska
Abstract:
Report of Investigation 2018-6, Geologic map of the Umiat-Gubik area, central North Slope, Alaska, provides a 1:63,360-scale geologic map of the hydrocarbon-bearing Umiat-Gubik area of the central North Slope, Alaska, spans approximately 2,100 km2 at the northern extent of the Brooks Range foothills fold-and-thrust belt in the Colville foreland basin. This geologic map was prepared through assimilation of field observations, aerial and satellite imagery, seismic-reflection data, and well logs. Near-surface formation picks were available or derived for most of the area's 24 exploration wells, and two cross-sections were constructed along lines of section that are constrained at depth by our interpretations of publicly available two-dimensional seismic data. The mapped area hosts exposures of Upper Cretaceous strata in the Nanushuk, Seabee, Tuluvak, Schrader Bluff, and Prince Creek Formations, constituting an approximately 2-km-thick succession that crops out discontinuously in the low-relief, tundra-mantled region. This part of the siliciclastic Brookian megasequence stratigraphy comprises principally shallow-marine deposits. Our work benefits from and reflects recent sequence-stratigraphic advances that better constrain how this part of the Colville basin continued to fill by a northeastward prograding clastic wedge during Late Cretaceous time, with the exposed stratigraphy recognized as basin-scale topset units. A series of east- to east-southeast-trending, km-scale wavelength, gentle folds are mapped in the area. Anticlines are locally breached by thrusts and interpreted to be folded above faulted and penetratively deformed mid-Cretaceous Torok Formation. Undeveloped, sub-commercial (as of this writing) petroleum accumulations occur along doubly plunging anticlinal traps at three long-recognized fields in the map area: Umiat (mostly oil), Gubik (gas), and East Umiat (gas). The Umiat oil field structural culmination is modified by thrust faults that breach the surface, and the East Umiat gas field is associated with a north-dipping back-thrust that is evident in seismic data and cuts across the Upper Cretaceous stratigraphy; thrust faults near the Gubik gas field lie within and below the Torok Formation. Various interpretations have previously been published for some of the area's structures, with important implications for petroleum trap geometries in the gas-prone foothills region. We present new data and interpretations that support the inference of a principal, south-dipping thrust fault that breaches the north limb of Umiat anticline near Umiat. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30099.
Supplemental_Information:
This geodatabase is organized according to the AK GeMS mapping schema Hendricks, M.D., Ekberg, P.G., Athey, J.E., Wyatt, W.C., Willingham, A.L., and Naibert, T.J., 2021, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 170, 10 p. https://doi.org/10.14509/30669. The distribution package includes ESRI fonts and style files, along with usage instructions. Further documentation of the symbology is provided by Ekberg, P.G., Hendricks, M.D., and Athey, J.E., 2021, AK GeMS symbology: A description of the AK GeMS style file: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 169, 7 p. https://doi.org/10.14509/30584
  1. How might this data set be cited?
    Herriott, T.M., Wartes, M.A., Decker, P.L., Gillis, R.J., Shellenbaum, D.P., Willingham, A.L., and Mauel, D.J., 2018, Geologic map of the Umiat-Gubik area, central North Slope, Alaska: Report of Investigation RI 2018-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 55 p., 1 sheet, scale 1:63,360
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -153.000011
    East_Bounding_Coordinate: -151.061011
    North_Bounding_Coordinate: 69.510588
    South_Bounding_Coordinate: 69.239376
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2010
    Ending_Date: 2018
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: geodatabase
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a vector data set.
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 5
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -153
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000.000000
      False_Northing: 0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest .00000001
      Ordinates (y-coordinates) are specified to the nearest .00000001
      Planar coordinates are specified in Meters
      The horizontal datum used is NAD27.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.40000000037.
      The flattening of the ellipsoid used is 1/294.978698199999997.
  7. How does the data set describe geographic features?
    umiat_ak_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)
    umiat_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)
    umiat_gems_shapefile_pkg
    Shapefiles and open data files (Source: Alaska Division of Geological & Geophysical Surveys)

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
    The State of Alaska funded this study with additional support from the U.S. Geological Survey's National Cooperative Geologic Mapping Program (STATEMAP award number G12AC20187). Work by, and discussions with, Gil Mull, Dave LePain, and Dave Houseknecht were invaluable to this study. Ken Helmold, Dolores van der Kolk, Grant Shimer, Pete Flaig, Julie Houle, Meg Kramer, and Don Krouskop also shared their knowledge of the Umiat-Gubik area. Richard Kemnitz provided many insights regarding field logistics. Our field camps at Umiat were operated by Horst Expediting and 70 North. Helicopter pilot Tom 'Rat' Ratledge safely transported the crew during field campaigns. Trish Ekberg, Nina Harun, and Mike Hendricks served additional geographic information system (GIS) support. Simone Montayne managed metadata for this report. Kristen Janssen provided manuscript formatting and layout. We thank Dave LePain and Tom Homza for thorough reviews that improved the clarity and content of this paper.
  3. To whom should users address questions about the data?
    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    3354 College Road
    Fairbanks, AK
    USA

    (907)451-5020 (voice)
    (907)451-5050 (FAX)
    dggspubs@alaska.gov
    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our website (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.

Why was the data set created?

DGGS bedrock geologic mapping at a scale of 1:63,360 answers critical questions about the petroleum potential throughout the North Slope. The Energy Resources Section disseminates results of its work in public presentations and in high-quality, open-source, peer-reviewed publications. Umiat-Gubik and surrounding areas have long been recognized for their importance in understanding the geologic evolution of northern Alaska. Undeveloped, sub-commercial (as of this writing) petroleum accumulations occur along doubly plunging anticlinal traps at three long-recognized fields in the map area: Umiat (mostly oil), Gubik (gas), and East Umiat (gas).

How was the data set created?

  1. From what previous works were the data drawn?
    Brosge, W.P. and Whittington, C.L., 1966 (source 1 of 11)
    Brosge, W.P., and Whittington, C.L., 1966, Geology of the Umiat-Maybe Creek region, Alaska: Professional Paper P 303-H, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: p. 501-638, 9 sheets
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    Carter, L.D. and Galloway, J.P., 1986 (source 2 of 11)
    Carter, L.D., and Galloway, J.P., 1986, Engineering - geologic maps of northern Alaska, Umiat Quadrangle: Open-File Report OF 86-335, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 16 p., 2 sheets, scale 1:250,000
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 250000
    Source_Contribution: Geologic map compilation
    Collins, F.R., 1958 (source 3 of 11)
    Collins, F.R., 1958, Test wells, Umiat area, Alaska: Professional Paper P 305-B, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: p. 71-206, 3 sheets
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    Detterman, R.L. and others, 1963 (source 4 of 11)
    Detterman, R.L., Bickel, R.S., and Gryc, George, 1963, Geology of the Chandler River region, Alaska: Professional Paper P 303-E, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: p. 233-324, 16 sheets, scale 1:125,000
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 125000
    Source_Contribution: Geologic map compilation
    Ekberg, P.G. and others, 2021 (source 5 of 11)
    Ekberg, P.G., Hendricks, M.D., and Athey, J.E., 2021, AK GeMS symbology: A description of the AK GeMS style file: Miscellaneous Publication MP 169, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 7 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    Hendricks, M.D. and others, 2021 (source 6 of 11)
    Hendricks, M.D., Ekberg, P.G., Athey, J.E., Wyatt, W.C., Willingham, A.L., and Naibert, T.J., 2021, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Miscellaneous Publication MP 170, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 10 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    Kumar, Naresh and others, 2002 (source 7 of 11)
    Kumar, Naresh, Bird, K.J., Nelson, P.H., Grow, J.A., and Evans, K.R., 2002, A digital atlas of hydrocarbon accumulations within and adjacent to the National Petroleum Reserve-Alaska (NPRA): Open-File Report OF 2002-71, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 80 p
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    LePain, D.L. and others, 2009 (source 8 of 11)
    LePain, D.L., McCarthy, P.J., and Kirkham, R.A., 2009, Sedimentology and sequence stratigraphy of the middle Albian-Cenomanian Nanushuk Formation in outcrop, central North Slope, Alaska: Report of Investigation RI 2009-1 v. 2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 76 p., 1 sheet
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    Mull, C.G. and others, 2004 (source 9 of 11)
    Mull, C.G., Houseknecht, D.W., Pessel, G.H., and Garrity, C.P., 2004, Geologic map of the Umiat Quadrangle, Alaska: Scientific Investigations Map SIM 2817-A, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:250,000
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 250000
    Source_Contribution: Geologic map compilation
    Robinson, F.M., 1958 (source 10 of 11)
    Robinson, F.M., 1958, Test wells, Gubik area, Alaska: Professional Paper P 305-C, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: p. 207-264, 2 sheets
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020 (source 11 of 11)
    U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020, GeMS (Geologic Map Schema)—A standard format for the digital publication of geologic maps: Techniques and Methods TM 11-B10, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 1 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
  2. How were the data generated, processed, and modified?
    Date: 2011 (process 1 of 3)
    Bedrock geologic mapping - The Alaska Divisions of Geological & Geophysical Surveys (DGGS) and Oil and Gas (DOG) conducted field studies near Umiat, Alaska, examining the region's Cretaceous stratigraphy and structural geology. We conducted two field campaigns in the Umiat-Gubik area (2010, 2011), mapping the geology of the Umiat B-5, B-4, B-3, and westernmost part of B-2 quadrangles (1:63,360-scale) on paper topographic maps and approximately 1:60,000-scale aerial photographs (Alaska High Aerial Photography [AHAP] circa 1978-1982). Field mapping was principally completed with helicopter transportation between widely spaced outcrops. In addition, we traversed on foot any laterally extensive or closely spaced outcrops. Tundra-mantled uplands constitute most of the field area and are generally devoid of outcrops, but curvilinear trends of subcrop, rubble-crop, and outcrop occur in hilly terrain northwest of the Colville River and were mapped on aerial photographs and satellite imagery. We field-checked traceable beds that were locally correlated to bluff-scale outcrops, rendering high-confidence stratigraphic and structural constraints in otherwise covered areas. Geologists observed details about the variations in texture, lithology, and orientation of the map units, collected rock samples, noted outcrop descriptions, and conducted structural measurements. We integrated numerous datasets to complete the interpretive mapping, including field observations, aerial and satellite imagery, seismic-reflection data, and well logs. In addition, selected samples were submitted for geochronologic and geochemical analysis, and the results were used to further interpret the stratigraphic and structural history of the map area.
    Date: 2017 (process 2 of 3)
    Geologic map compilation - Field observations were integrated with existing literature. Station locations for orientation measurements and rock samples were collected using hand-held recreation-grade GPS units. The mapped surficial geology is limited to alluvial deposits associated with modern rivers and creeks and simplified from Carter and Galloway (1986). Map unit boundaries and structures were compiled in an ArcGIS geodatabase using NAD27 base maps and aerial photography. The map and report received technical review and editing by several scientists familiar with the subject matter. The authors incorporated the reviewers' suggestions into the final draft when deemed appropriate. Data sources used in this process:
    • Brosge, W.P. and Whittington, C.L., 1966
    • Carter, L.D. and Galloway, J.P., 1986
    • Collins, F.R., 1958
    • Detterman, R.L. and others, 1963
    • Kumar, Naresh and others, 2002
    • LePain, D.L. and others, 2009
    • Mull, C.G. and others, 2004
    • Robinson, F.M., 1958
    Date: 2021 (process 3 of 3)
    GIS analysis and digital cartography - This data distribution package's geologic and geographic features were organized and attributed according to the AK GeMS geologic mapping schema. The data were then programmatically transformed to provide download options in three formats: (1) an AK GeMS data package that includes the complete AK GeMS database and associated files, (2) a GeMS data package that is a conversion of the AK GeMS database into the base GeMS standard published by the USGS, and (3) a shapefile data package that includes two simple shapefile representations of the data. Data sources used in this process:
    • Ekberg, P.G. and others, 2021
    • Hendricks, M.D. and others, 2021
    • U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020
  3. What similar or related data should the user be aware of?
    Herriott, T.M., Wartes, M.A., Decker, P.L., Gillis, R.J., Shellenbaum, D.P., Mauel, D.J., and Helmold, K.P., 2015, Geologic map of the Umiat-Gubik area, central North Slope, Alaska - Integration of fieldwork and subsurface data in a region of known oil and gas accumulations (poster): Geological Society of America, Cordilleran Section Annual Meeting, May 11-13, 2015, Anchorage, Alaska: Poster and Presentation Herriott, T.M. and others, 2015, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    Certainty in attribute interpretation varies throughout the map and is scale-dependent. Attribute fields within each feature class record the authors' degree of confidence in the existence or identity of applicable features.
  2. How accurate are the geographic locations?
    Certainty in feature boundaries or location varies throughout the map. Data fields within each feature class and the accompanying orientation and location confidence lookup tables record the authors' degree of confidence in the location of applicable features.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This publication is released as a DGGS Report of Investigations (RI). An RI is the completed product of original research and analysis, and RIs use professional cartography and undergo rigorous peer review, editing, and revision.
  5. How consistent are the relationships among the observations, including topology?
    All polygon features were topologically validated according to specifications of the AK GeMS geologic mapping schema.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints:
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
Use_Constraints:
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. The 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. 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.
  1. Who distributes the data set? (Distributor 1 of 1)
    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    3354 College Road
    Fairbanks, AK
    USA

    (907)451-5020 (voice)
    (907)451-5050 (FAX)
    dggspubs@alaska.gov
    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our website (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
  2. What's the catalog number I need to order this data set? RI 2018-6
  3. What legal disclaimers am I supposed to read?
    The State of Alaska makes no expressed 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.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 01-Sep-2021
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Attn: Simone Montayne
Metadata Manager
3354 College Road
Fairbanks, AK
USA

(907)451-5020 (voice)
(907)451-5050 (FAX)
dggspubs@alaska.gov
Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.9.50 on Wed Sep 01 12:12:20 2021