border: outline shape of the study area contact: engineering-geologic unit outlines materials: engineering-geologic units photolinear: linear features visible on aerial photographs pingo: pingo locations
Stevens, D.S.P., 2012, Engineering-geologic map of the Eagle A-1 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2002-1D, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
This is a Vector data set.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.000001
Ordinates (y-coordinates) are specified to the nearest 0.000001
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1927.
The ellipsoid used is North American Datum of 1927.
The semi-major axis of the ellipsoid used is 6378206.4.
The flattening of the ellipsoid used is 1/294.9786982.
| Value | Definition |
|---|---|
| approximately located | approximately located unit contact |
| Value | Definition |
|---|---|
| BC | Medium-jointed, fine- to coarse-grained sedimentary carbonate rocks and their metamorphic equivalents. Includes limestone and marble. |
| BG | Coarse-jointed, coarse-grained igneous lithologies and their metamorphic equivalents. Chiefly granitic rocks. Includes coarse-grained gneiss. |
| BM | Medium-jointed, fine- to medium-grained quartzose sedimentary rocks and their metamorphic equivalents. Chiefly quartzite in this map area. |
| BO | Rocks of lithologies that are (a) not listed in other materials classes, but which may be suited for use as construction materials or for other specialized purposes, and (b) mixed units composed of combinations of the above bedrock materials classes. Includes fine-grained gneiss and phyllite. |
| BS | Fine- to coarse-grained mafic plutonic rocks and their metamorphic equivalents. Includes metagabbro and serpentinite. |
| BU | Rocks of mixed lithology and/or very fine-grained sedimentary lithologies that are generally poorly suited for use as construction materials. Includes coal-bearing Tertiary sediments. |
| BV | Medium-jointed, fine-grained igneous rocks and their metamorphic equivalents. Chiefly metavolcanics and dikes. |
| GM | Poorly- to moderately well-sorted clay, silt, sand, gravel, and diamicton of colluvial, fluvial, and glacial origins. Includes angular, unsorted talus debris and chaotically deformed colluvium derived from landslides. Engineering applications vary widely due to large range of grain size and sorting properties. Commonly frozen. Estimated 20 to 80 percent coarse, granular deposits with considerable oversized material. Includes primarily GC and GM of the Unified Soil Classification System (Wagner, 1957). |
| GS | Fluvial and glaciofluvial gravel, sand, and silt. Chiefly (estimated >80 percent) clean sand and gravel. Grain size, sorting, and degree of stratification are variable. Permafrost may be present, especially in older deposits. Older deposits may contain highly weathered clasts and thus may not be suitable as construction materials. Rare oversized materials may include boulders. Includes primarily GP and GW of the Unified Soil Classification System (Wagner, 1957). |
| OR | Organic-rich silt and peat in bogs, former stream channels, and lake basins. Commonly frozen and ice-rich due to the excellent insulating properties of peat. Generally water-saturated. Chiefly organic materials. Estimated >50 percent peat, organic sand, or organic silt. Includes Pt of the Unified Soil Classification System (Wagner, 1957). |
| SM | Silt deposited primarily by wind and reworked by fluvial and colluvial processes. May be organic rich. Commonly frozen and ice-rich, especially on north-facing slopes. Chiefly fine materials. Estimated >80 percent silt, sand, and clay. Includes primarily ML, MH, and SM of the Unified Soil Classification System (Wagner, 1957). |
| Value | Definition |
|---|---|
| photolinear feature | linear feature visible on aerial photographs |
| Value | Definition |
|---|---|
| pingo | pingo location |
This project is part of the Alaska Airborne Geophysical/Geological Mineral Inventory Program funded by the Alaska State Legislature and managed by State of Alaska, Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS). Partial funding for the geologic mapping was also provided by the U.S. Geological Survey, National Cooperative Geologic Mapping Program, under STATEMAP Award No. 01HQAG0054.
907-451-5029 (voice)
dggsgis@alaska.gov
This project, resulting map, geospatial data was intended to provide a geologic map and a geologic interpretation of the Fortymile mining district at 1:63,360 scale. Previous published 1:63,360 scale geologic maps of this area were reconnaissance-level maps or only covered portions of the quadrangle. Mapping at 1:63,360 scale (or more detailed) was needed to identify critical geologic features that may relate to more regional structures or geologic units.
Wagner, A.A., 1957, The use of the Unified Soil Classification System by the Bureau of Reclamation:: Proceedings, 4th International Conference on Soil Mechanics and Foundation Engineering vol. I, p. 125., International Conference on Soil Mechanics and Foundation Engineering, London, England.
Data sources used in this process:
Pinney, D.S., 2001, Engineering-geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3D, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Pinney, D.S., 2001, Surficial-geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3C, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Stevens, D.S.P., and Burns, P.A.C., 2010, Surficial-geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Preliminary Interpretive Report PIR 2002-1C, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Szumigala, D.J., Newberry, R.J., Werdon, M.B., Athey, J.E., Flynn, R.L., and Clautice, K.H., 2002, Bedrock geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Preliminary Interpretive Report PIR 2002-1B, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Szumigala, D.J., Newberry, R.J., Werdon, M.B., Athey, J.E., Stevens, D.S.P., Flynn, R.L., Clautice, K.H., and Craw, P.A., 2002, Geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Preliminary Interpretive Report PIR 2002-1A, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Szumigala, D.J., Newberry, R.J., Werdon, M.B., Finseth, B.A., and Pinney, D.S., 2000, Preliminary bedrock geologic map of a portion of the Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2000-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Werdon, M.B., Newberry, R.J., Szumigala, D.J., and Pinney, D.S., 2001, Geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3A, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
Werdon, M.B., Newberry, R.J., and Szumigala, D.J., 2001, Bedrock geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3B, Alaska Division of Geological & Geophysical Surveys, Fairbanks, AK, USA.Online Links:
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, investigative traverses throughout the map area, aerial reconnaissance via helicopter, and examination of road-cuts and river exposures. Engineering-geologic map units were derived from the surficial-geologic map (PIR 2002-3C). Physical properties of engineering-geologic map units are interpretive, based on extrapolation from verified localities and from previously published reports and data. This map has received two technical reviews by scientists familiar with the subject matter. We incorporated the reviewer's suggestions into the final draft.
Surficial mappers recorded observations on 1:65,000-scale (nominal) color-infrared aerial photographs and 1:63,360 scale topographic base maps. We believe the total horizontal accuracy of the mapped surficial-geologic contacts is on the order of 25 m or better, with somewhat lesser accuracy expected in areas of rugged relief.
This dataset includes shapefiles that contain information about the mapped and interpreted engineering-geologic deposits in the map area distinguishable at a scale of 1:63,360. No analytical tests were conducted for this report. The table describes engineering properties that are generally present in the mapped surficial deposits, but local variations and exceptions are most certainly to be expected. The reader is therefore cautioned that this map is intended only as a general guide, and that unevaluated geologic resources and hazards may be present. Detailed geotechnical investigations should be conducted prior to utilization of any map units for engineering purposes.
Polygon topology was present and clean on the original Arc GIS coverages. All polygon features were topologically validated using ArcGIS prior to export to shapefile format.
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.
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PIR 2002-1D
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 requestor or anyone else exceed the fee paid for the electronic service or product.
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 by mail, phone, fax, or email from the DGGS Fairbanks office. 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. Turnaround 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 the exact shipping amount.
| Data format: | vector digital data |
|---|---|
| Network links: |
<http://dx.doi.org/10.14509/24544> |
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