border: A polygon that encompasses the geographic extent of the data observations. ContactsAndFaults: Line features depicting faults and geologic contacts DataSourcePolys: Polygons that delineate data sources for various parts of the map FossilPoints: Fossil location points GeochronPoints: Geochronology sample location points GeologicLines: Dikes, coal seams, ash beds, glacial features, anticline and syncline hinge-surface traces, and other kinds of key beds that do not participate in map-unit topology MapUnitPolys: Polygons that record the distribution of mapped or interpreted geologic units OrientationPoints: A point file that provides field station locations, symbology, and associated structure data (bedding attitudes, foliation attitudes, slip vectors measured at a point, etc.) Stations: A point file that provides location information, observations, and other data specific to each field observation station.
Twelker, Evan, Hubbard, T.D., Wypych, Alicja, Sicard, K.R., Newberry, R.J., Reioux, D.A., Freeman, L.K., and Lande, L.L., 2015, Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska: Preliminary Interpretive Report PIR 2015-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
This is a vector data set.
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 North American Datum of 1927.
The ellipsoid used is Clarke 1866.
The semi-major axis of the ellipsoid used is 6378206.4.
The flattening of the ellipsoid used is 1/294.9786982.
The line features are: Fault, Surficial Contact, Contact, and Inferred thrust fault
| Value | Definition |
|---|---|
| N | The feature IS NOT covered by an overlying map unit. |
| Y | The feature IS covered by an overlying map unit. |
| Value | Definition |
|---|---|
| Certain | Indicates that the author has sufficient observational and/or other supporting data to be reasonably confident in the scientific credibility of the interpretation of the feature. The level of certainty is specific to the map scale. |
| Questionable | The interpretation of the feature at the mapped scale fits the overall proposed geologic model but the extent and/or classification is questionable or uncertain due to insufficient observations and/or supporting data. |
| Value | Definition |
|---|---|
| Certain | Indicates that the author has sufficient observational and/or other supporting data to be reasonably confident in the scientific credibility of the interpretation of the feature. The level of certainty is specific to the map scale. |
| Questionable | The interpretation of the feature at the mapped scale fits the overall proposed geologic model but the extent and/or classification is questionable or uncertain due to insufficient observations and/or supporting data. |
| Range of values | |
|---|---|
| Minimum: | 10 |
| Maximum: | 250 |
| Units: | meters |
| Formal codeset | |
|---|---|
| Codeset Name: | FGDC Digital Cartographic Standard for Geologic Map Symbolization; Appendix A. Geologic map symbols, colors, and patterns, "REF NO" field |
| Codeset Source: | Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. |
The labeled features are: SLOT LAKE FAULT, CENTRAL RAINGELLIA FAULT, and RANGE FRONT FAULT
The notes indicate the basis of the feature interpretation: "Inferred from SDMI IfSAR orthorectified radar intensity image", "Adapted from Adams and others (1985; unpublished) Plate 1", "Adapted from Oswald (2006) Map B", "Break in 900Hz EM", "Location inferred from airborne magnetic survey", and "Location inferred from airborne resistivity survey"
The notes indicate the basis of the feature interpretation: "Oswald, 2006 (Map B)", "Adams and others, 1985 (unpublished) (Plate 2)", "Rose, 1967 (GR 32)", "Amos and Cole, 2001 (Map B)", "Oswald, 2006 (Map A)", "Adams and others, 1985 (unpublished) (Plate 1)", and "Van Wyck, 2006 (Figure 6)"
Generic example of a sample identifier: YYYYAAA9999X: YY or YYYY= year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database.
free text that is intended to display adjacent to the label point on the map
free text description of the rock sample; transcribed from geologists' field notes
| Range of values | |
|---|---|
| Minimum: | 50000 |
| Maximum: | 50000 |
| Range of values | |
|---|---|
| Minimum: | 10 |
| Maximum: | 10 |
| Units: | meters |
free text description of the fossil
free text description of the fossil age
The notes indicate the source of the feature interpretation: " and "this study (R.B. Blodgett)"
The samples were analyzed by: ArAr
Generic example of a sample identifier: YYYYAAA9999X: YY or YYYY= year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database.
| Value | Definition |
|---|---|
| Khg | HORNBLENDE GABBRO (Cretaceous) |
| PPva | ALTERED METAVOLCANIC ROCKS (Pennsylvanian to Permian) |
| Trg1 | GABBRO, AFFILIATED WITH UNIT Trn1 (Late Triassic) |
| Trr1 | LOWER RHYOLITE (Tertiary) |
| Jgd | GRANODIORITE TO TONALITE (Middle Jurassic) |
| Kg | GRANITIC ROCKS (Late Cretaceous) |
| Kdp | DACITE PORPHYRY (Late Cretaceous) |
| Ttap | ANDESITE PORPHYRY (Tertiary) |
| JPza | AMPHIBOLITE (Late Paleozoic to Early Jurassic) |
| Tsdp | DACITE PORPHYRY (Tertiary) |
| Tsb | BASALT FLOWS (Tertiary) |
| Tril | INTERLAYERED UNIT (Tertiary) |
| TrPs | METASEDIMENTARY ROCKS (Pennsylvanian to Triassic) |
free text that is intended to display adjacent to the label point on the map
free text description of the rock sample; transcribed from geologists' field notes
| Range of values | |
|---|---|
| Minimum: | 50000 |
| Maximum: | 50000 |
| Range of values | |
|---|---|
| Minimum: | 10 |
| Maximum: | 10 |
| Units: | meters |
| Range of values | |
|---|---|
| Minimum: | 21.6 |
| Maximum: | 223 |
| Units: | MA (million years ago) |
| Range of values | |
|---|---|
| Minimum: | 0.2 |
| Maximum: | 4 |
| Units: | MA (million years ago) |
| Range of values | |
|---|---|
| Minimum: | 0.2 |
| Maximum: | 4 |
| Units: | Ma (million years ago) |
| Value | Definition |
|---|---|
| Ma | million years ago |
The notes indicate the source of the feature interpretation: "Benowitz and others, 2015", "Oswald, 2006", and "Benowitz and others, 2014"
The line features are: Syncline, Anticline, BasaltDike, IntermediateDike, Esker, and Moraine
| Value | Definition |
|---|---|
| N | The feature IS NOT covered by an overlying map unit. |
| Value | Definition |
|---|---|
| Certain | Indicates that the author has sufficient observational and/or other supporting data to be reasonably confident in the scientific credibility of the interpretation of the feature. The level of certainty is specific to the map scale. |
| Value | Definition |
|---|---|
| Certain | Indicates that the author has sufficient observational and/or other supporting data to be reasonably confident in the scientific credibility of the interpretation of the feature. The level of certainty is specific to the map scale. |
| Range of values | |
|---|---|
| Minimum: | 50 |
| Maximum: | 250 |
| Units: | meters |
| Formal codeset | |
|---|---|
| Codeset Name: | FGDC Digital Cartographic Standard for Geologic Map Symbolization; Appendix A. Geologic map symbols, colors, and patterns, "REF NO" field |
| Codeset Source: | Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. |
| Value | Definition |
|---|---|
| JPza | AMPHIBOLITE (Late Paleozoic to Early Jurassic) |
| JPzog | ORTHOGNEISS (Late Paleozoic to Early Jurassic) |
| JPzpg | PARAGNEISS (Late Paleozoic to Early Jurassic) |
| Jgd | GRANODIORITE TO TONALITE (Middle Jurassic) |
| KJmf | METAFLYSCH (Late Jurassic to Early Cretaceous) |
| Kdp | DACITE PORPHYRY (Late Cretaceous) |
| Kg | GRANITIC ROCKS (Late Cretaceous) |
| Khg | HORNBLENDE GABBRO (Cretaceous) |
| PPfv | FELSIC METAVOLCANIC ROCKS (Pennsylvanian to Permian) |
| PPmv | MAFIC TO INTERMEDIATE METAVOLCANIC ROCKS (Pennsylvanian to Permian) |
| PPva | ALTERED METAVOLCANIC ROCKS (Pennsylvanian to Permian) |
| Pl | LIMESTONE AND MARBLE (Late Permian) |
| Qa | UNDIFFERENTIATED FLOODPLAIN ALLUVIUM |
| Qaa | ACTIVE-FLOODPLAIN ALLUVIUM |
| Qaf | ALLUVIAL-FAN DEPOSITS |
| Qai | INACTIVE-FLOODPLAIN ALLUVIUM |
| Qc | UNDIFFERENTIATED COLLUVIUM |
| Qcd | DEBRIS-FLOW DEPOSITS |
| Qcf | MIXED COLLUVIUM AND ALLUVIUM |
| Qcg | ROCK GLACIER DEPOSITS |
| Qct | TALUS |
| Qgd1 | DRIFT OF EARLY WISCONSINAN AGE (75,000 TO 40,000 Y.B.P.) |
| Qgd2 | DRIFT OF LATE WISCONSINAN AGE, UNDIFFERENTIATED (25,000 TO 11,000 Y.B.P.) |
| Qgd3 | TILL AND ASSOCIATED MORAINAL DEPOSITS OF LATEST WISCONSINAN AGE (11,000 TO 9,000 Y.B.P.) |
| Qgds1 | ICE STAGNATION TILL OF EARLY WISCONSINAN AGE (75,000 TO 40,000 Y.B.P.) |
| Qgds3 | ICE STAGNATION TILL OF LATEST WISCONSINAN AGE (11,000 TO 9,000 YEARS BEFORE PRESENT [Y.B.P.]) |
| Qgf2 | OUTWASH OF LATE WISCONSINAN AGE, UNDIFFERENTIATED |
| Qgf3 | OUTWASH OF LATEST WISCONSINAN AGE |
| Ql | LACUSTRINE DEPOSITS |
| Qld | LAKE DELTA DEPOSITS |
| Qp | SWAMP DEPOSITS |
| Tdb | BASALT (Tertiary) |
| TrPs | METASEDIMENTARY ROCKS (Pennsylvanian to Triassic) |
| Trg | GABBRO (Late Triassic) |
| Trg1 | GABBRO, AFFILIATED WITH UNIT Trn1 (Late Triassic) |
| Trg2 | GABBRO, AFFILIATED WITH UNIT Trn2 (Late Triassic) |
| Tril | INTERLAYERED UNIT (Tertiary) |
| Triv | INTERMEDIATE VOLCANICLASTIC ROCKS (Tertiary) |
| Trl | LIMESTONE AND MARBLE (Late Triassic) |
| Trn1 | NIKOLAI GREENSTONE, LOWER MEMBER (Late Triassic) |
| Trn2 | NIKOLAI GREENS TONE, UPPER MEMBER (Late Triassic) |
| Trr1 | LOWER RHYOLITE (Tertiary) |
| Trr2 | UPPER RHYOLITE (Tertiary) |
| Trrp | RHYOLITE PORPHYRY (Tertiary) |
| Trsv | METASEDIMENTARY AND METAVOLCANIC ROCKS (Late Triassic) |
| Tsa | ANDESITE FLOWS (Tertiary) |
| Tsb | BASALT FLOWS (Tertiary) |
| Tsd | DACITE (Tertiary) |
| Tsdp | DACITE PORPHYRY (Tertiary) |
| Tsr | RHYOLITE (Tertiary) |
| Tta | ANDESITE FLOWS (Tertiary) |
| Ttap | ANDESITE PORPHYRY (Tertiary) |
| Ttb | BASALT FLOWS (Tertiary) |
| Ttd | DACITE FLOWS (Tertiary) |
| Water | polygon is a waterbody |
| Value | Definition |
|---|---|
| Certain | Indicates that the author has sufficient observational and/or other supporting data to be reasonably confident in the scientific credibility of the interpretation of the feature. The level of certainty is specific to the map scale. |
| Questionable | The interpretation of the feature at the mapped scale fits the overall proposed geologic model but the extent and/or classification is questionable or uncertain due to insufficient observations and/or supporting data. |
| Value | Definition |
|---|---|
| NULL | not applicable |
| Formal codeset | |
|---|---|
| Codeset Name: | FGDCGeoAge font |
| Codeset Source: | Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. |
| Value | Definition |
|---|---|
| 0AX0 | CMYK value - C:0%, M:8%, Y:100%, K:0% |
| 00X0 | CMYK value - C:0%, M:0%, Y:100%, K:0% |
| 0A40 | CMYK value - C:0%, M:8%, Y:40%, K:0% |
| 0060 | CMYK value - C:0%, M:0%, Y:60%, K:0% |
| 0A60 | CMYK value - C:0%, M:8%, Y:60%, K:0% |
| 0150 | CMYK value - C:0%, M:13%, Y:50%, K:0% |
| 01X0 | CMYK value - C:0%, M:13%, Y:100%, K:0% |
| 0030 | CMYK value - C:0%, M:0%, Y:30%, K:0% |
| 0020 | CMYK value - C:0%, M:0%, Y:20%, K:0% |
| 0040 | CMYK value - C:0%, M:0%, Y:40%, K:0% |
| 0050 | CMYK value - C:0%, M:0%, Y:50%, K:0% |
| 0A50 | CMYK value - C:0%, M:8%, Y:50%, K:0% |
| 0010 | CMYK value - C:0%, M:0%, Y:13%, K:0% |
| 0070 | CMYK value - C:0%, M:0%, Y:70%, K:0% |
| 2XX0 | CMYK value - C:20%, M:100%, Y:100%, K:0% |
| X160 | CMYK value - C:100%, M:13%, Y:60%, K:0% |
| 3X60 | CMYK value - C:30%, M:100%, Y:60%, K:0% |
| 3X40 | CMYK value - C:30%, M:100%, Y:40%, K:0% |
| 3XA0 | CMYK value - C:30%, M:100%, Y:8%, K:0% |
| X360 | CMYK value - C:100%, M:30%, Y:60%, K:0% |
| X530 | CMYK value - C:100%, M:50%, Y:30%, K:0% |
| X440 | CMYK value - C:100%, M:40%, Y:40%, K:0% |
| 0500 | CMYK value - C:0%, M:50%, Y:0%, K:0% |
| 17X0 | CMYK value - C:13%, M:70%, Y:100%, K:0% |
| 13X0 | CMYK value - C:13%, M:30%, Y:100%, K:0% |
| 62A0 | CMYK value - C:60%, M:20%, Y:8%, K:0% |
| 2000 | CMYK value - C:20%, M:0%, Y:0%, K:0% |
| 50A0 | CMYK value - C:50%, M:0%, Y:8%, K:0% |
| 0550 | CMYK value - C:0%, M:50%, Y:50%, K:0% |
| X220 | CMYK value - C:100%, M:20%, Y:20%, K:0% |
| 0200 | CMYK value - C:0%, M:20%, Y:0%, K:0% |
| 1X60 | CMYK value - C:13%, M:100%, Y:60%, K:0% |
| 5310 | CMYK value - C:50%, M:30%, Y:13%, K:0% |
| 2X20 | CMYK value - C:20%, M:100%, Y:20%, K:0% |
| 52X0 | CMYK value - C:50%, M:20%, Y:100%, K:0% |
| 15X0 | CMYK value - C:13%, M:50%, Y:100%, K:0% |
| A260 | CMYK value - C:8%, M:20%, Y:60%, K:0% |
| 0450 | CMYK value - C:0%, M:40%, Y:50%, K:0% |
| 1530 | CMYK value - C:13%, M:50%, Y:30%, K:0% |
| 1330 | CMYK value - C:13%, M:30%, Y:30%, K:0% |
| 1430 | CMYK value - C:13%, M:40%, Y:30%, K:0% |
| 2540 | CMYK value - C:20%, M:50%, Y:40%, K:0% |
| A570 | CMYK value - C:8%, M:50%, Y:70%, K:0% |
| 0700 | CMYK value - C:0%, M:70%, Y:0%, K:0% |
| 4020 | CMYK value - C:40%, M:0%, Y:20%, K:0% |
| 0650 | CMYK value - C:0%, M:60%, Y:50%, K:0% |
The notes indicate the basis of the feature interpretation: "Plug", "inferred from 7200Hz", and "Outline based on topographic relief"
The type of feature measured: mylonitic foliation, cleavage, compaction foliation, joint surface, flow, schistosity, fault, shear band, metamorphic foliation, vein wall, bedding, fracture surface, boudinage, crenulation cleavage, dike wall, bedding with tops, dike contact, axial plane, igneous layering or foliation, bed parallel schistosity, slickenside surface, minor slip surface, gneissic layering, fold axis, slaty cleavage, outcrop trend, minor fault, igneous flow banding, major fault, bedding from photo, sill, spaced cleavage, mineral lineation, crenulation lineation, stretched mineral, slickenline, boudins, rods, intersection lineation, stretched pebble, fault trend, vein trend, hinge line, stretched clast, and striation
Generic example of a sample identifier: YYYYAAA9999X: YY or YYYY= year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database.
| Formal codeset | |
|---|---|
| Codeset Name: | FGDC Digital Cartographic Standard for Geologic Map Symbolization; Appendix A. Geologic map symbols, colors, and patterns, "REF NO" field |
| Codeset Source: | Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. |
free text that is intended to display adjacent to the label point on the map
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 50000 |
| Range of values | |
|---|---|
| Minimum: | 10 |
| Maximum: | 250 |
| Units: | meters |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Value | Definition |
|---|---|
| Certain | Indicates that the author has sufficient observational and/or other supporting data to be reasonably confident in the scientific credibility of the interpretation of the feature. The level of certainty is specific to the map scale. |
Generic example of a sample identifier: YYYYAAA9999X: YY or YYYY= year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database.
| Range of values | |
|---|---|
| Minimum: | 10 |
| Maximum: | 10 |
| Units: | meters |
| Value | Definition |
|---|---|
| handheld GPS | Location data were collected using an unspecified model of Global Positioning System (GPS) receiver. |
| Range of values | |
|---|---|
| Minimum: | 6/25/2014 |
| Maximum: | 8/3/2014 |
| Units: | Calendar Date |
Field investigators were: Freeman, Lawrence K., Lande, Lauren, Newberry, R.J, Reioux, David A., Sicard, Karri R., Twelker, Evan and Wypych, Alicja
Free text description. Note: the value may be truncated if the description exceeds 255 characters
This project is jointly funded by the State's Strategic and Critical Minerals Assessment program (part of the Airborne Geological/Geophysical Mineral Inventory [AGGMI]) and the USGS National Cooperative Geologic Mapping Program, STATEMAP component, under award number G14AC00167 for 2014. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government. We acknowledge Cook Inlet Region Inc. (CIRI), Chickaloon Moose Creek Native Association, Knikatnu, Ninilchik Natives Association, Salamatof Native Association, Seldovia Native Association, and Tyonek Native Corporation for supporting the project and providing access to private lands in the mapping area. Brenda Becker of the Bureau of Land Management (BLM) Glennallen Field Office assisted us with permitting on BLM-managed lands. We thank Peter Oswald, Jeanine Schmidt, Melanie Werdon, Ben Porterfield, David Adams, Laurel Burns, Ken Ridgway, and others for geological discussions that helped us prepare for the field and understand our results when we returned. Jeff Benowitz and Paul Layer of the University of Alaska Fairbanks (UAF) Geochronology Lab provided 40Ar/39Ar analyses and assisted us in their interpretation, and Ken Severin of the UAF Advanced Instrumentation Laboratory assisted us with the microprobe. Scott Arko of the UAF Alaska Satellite Facility furnished us with orthorectified areal imagery. We appreciate the attempts of Paul O'Sullivan and GeoSep Services to recover zircons from some of our undated map units. Robert Blodgett provided us with fossil identifications and supporting discussions. Melanie Werdon and De Anne Stevens gave timely and constructive reviews. We appreciate the warm hospitality and logistical support of Jessi Braga and Stephan Lake Lodge, and we thank Alpine Air Alaska pilots Martin Hoessinger and Jared Berman for skilled and safe flying.
(907)451-5020 (voice)
dggsgis@alaska.gov
The Alaska Division of Geological and Geophysical Surveys (DGGS) initiated a multi-year project to improve the understanding of mineral potential in western Wrangellia. The project began in 2013 with acquisition of magnetic and electromagnetic (EM) geophysical data over unsurveyed portions of the terrane in the Clearwater and Talkeetna Mountains. DGGS geologists completed a three week field program of geologic mapping, rock, and stream sediment sampling in 2013, and followed up with 1:50,000-scale mapping of the Talkeetna Mountains C-4 Quadrangle during the 2014 field season.
Burns, L.E., Geoterrex-Dighem, WGM, Inc., Emond, A.M., and Graham, G.R.C., 2014, Iron Creek airborne electromagnetic and magnetic geophysical survey data compilation: Geophysical Report GPR 2014-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Clautice, K.H., Newberry, R.J., Blodgett, R.B., Bundtzen, T.K., Gage, B.G., Harris, E.E., Liss, S.A., Miller, M.L., Reifenstuhl, R.R., Clough, J.G., and Pinney, D.S., 2001, Bedrock geologic map of the Chulitna region, southcentral Alaska: Report of Investigation RI 2001-1A, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Schmidt, J.M., Werdon, M.B., and Wardlaw, Bruce, 2003, New mapping near Iron Creek, Talkeetna Mountains, indicates presence of Nikolai greenstone: Professional Report PR 120J, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Werdon, M.B., Riehle, J.R., Schmidt, J.M., Newberry, R.J., and Pessel, G.H., 2002, Geologic map of the Iron Creek area, Talkeetna Mountains B-5 Quadrangle, Alaska: Preliminary Interpretive Report PIR 2002-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Data sources used in this process:
Benowitz, J.A., Layer, P.W., Wypych, Alicja, and Twelker, Evan, 2015, 40Ar/39Ar data from the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska: Raw Data File RDF 2015-10, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Benowitz, J.A., Layer, P.W., and Twelker, Evan, 2014, 40Ar/39Ar data from rocks collected in 2013 in the Wrangellia mineral assessment area, Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles, Alaska: Raw Data File RDF 2014-18, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Twelker, Evan, Bachmann, E.N., Freeman, L.K., Newberry, R.J., Reioux, D.A., Sicard, K.R., Tuzzolino, A.L., Wright, T.C., and Wypych, Alicja, 2014, Major-oxide, minor-oxide, and trace-element geochemical data from rocks and stream sediments in the Wrangellia mineral assessment area, Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles, Alaska: Raw Data File RDF 2014-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Twelker, Evan, Newberry, R.J., Freeman, L.K., Sicard, K.R., Reioux, D.A., and Bachmann, E.N., 2013, DGGS geologic and mineral-resource assessment of the western Wrangellia terrane, central Alaska: Initial progress report (presentation): Alaska Miners Association Annual Convention, Anchorage, Alaska, November 4-10, 2013: Poster and Presentation Twelker, Evan and others, 2013, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Twelker, Evan, Wypych, Alicja, Sicard, K.R., Newberry, R.J., Freeman, L.K., Reioux, D.A., and Lande, Lauren, 2014, Preliminary results from 2014 geologic mapping in the Talkeetna Mountains, Alaska (presentation): Alaska Miners Association Annual Convention, Anchorage, Alaska, November 3-9, 2014: Poster and Presentation Twelker, Evan and others, 2014, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Twelker, Evan, Wypych, Alicja, and Newberry, R.J., 2014, New Data and Insight on the Late Triassic Wrangellia Magmatic Ni-Cu-Co-PGE System in the Talkeetna Mountains, Central Alaska (poster): Society of Economic Geologists 2014 Conference, September 27-30, 2014: Poster and Presentation Twelker, Evan and others, 2014, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Twelker, Evan, and Burns, L.E., 2014, New geochemical and geophysical data from the western Wrangellia minerals assessment area (presentation): Alaska Miners Association 24th Biennial Mining Conference, Fairbanks, Alaska April 7-13, 2014: Poster and Presentation Twelker, Evan and Burns, L.E., 2014, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Wypych, Alicja, Twelker, Evan, Freeman, L.K., Lande, Lauren, Newberry, R.J., Reioux, D.A., and Sicard, K.R., 2014, Major-oxide and trace-element geochemical data from rocks collected in 2014 in the Wrangellia mineral assessment area, Talkeetna Mountains C-4, C-3, and B-4 quadrangles, Alaska: Raw Data File RDF 2014-22, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.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 map result from interpretation of false-color infrared aerial photographs, investigative traverses throughout the map area, aerial reconnaissance via helicopter, examination of exposures, geochemistry and geochronology analysis, and interpretation of geophysical survey data. The air-photo interpretations were adjusted as needed to be consistent with bedrock exposures identified by field geologists. Per NCGMP09 (USGS National Cooperative Geologic Mapping Program - Draft Standard Format for Digital Publication of Geologic Maps) specifications, the authors have assigned a confidence value to each polygon and line segment to indicate their degree of confidence in the positioning and identification of the element at the mapped scale. This publication is a PRELIMINARY INTERPRETIVE REPORT and is meant to allow rapid release of field observations or initial interpretations of geology or analytical data. It has not undergone formal peer review. Interpretations or conclusions contained in this publication are subject to change.
Mappers recorded observations on 1:63,360 scale (nominal) color-infrared aerial photographs and 1:63,360 scale USGS topographic base maps. The authors believe the total horizontal accuracy of directly observed mapped geologic contacts is on the order of 25 m or better, with somewhat lesser accuracy expected in areas of rugged relief. Per NCGMP09 specifications, the authors have assigned a confidence value to each polygon, line, or point to indicate their degree of confidence in the positioning and identification of the element at the mapped scale. Waterlines and waterbody polygons were entirely derived from topographic base maps, consequently it is possible that the mapped location and extent of these features may differ from modern ground conditions.
This report and digital dataset provides information about geologic features that can be identified or interpreted at a scale of 1:50,000. Relative to preexisting mapping, it offers an improved understanding of the geology, structural history, and mineral potential of the area. However, significant additional work would be required to fully resolve uncertainties in our interpretations.
Polygon topology was implemented per NCGMP09 specifications (polygons must not overlap, polygons must not have gaps, boundaries must be overlain by lines in ContactsAndFaults). All polygon features were topologically validated using ArcGIS for Desktop 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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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.
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: | Shapefiles |
|---|---|
| Network links: |
<http://dx.doi.org/10.14509/29470> |
(907)451-5020 (voice)