Benowitz, J.A. Layer, P.W. Sicard, K.R. 2014 report, Raw Data File RDF 2014-21 v. 1.0.1 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 13 p. http://dx.doi.org/10.14509/29134 This DGGS Raw Data File presents 40Ar/39Ar age dating results for selected igneous rocks encountered in the Styx River area of the western Alaska Range. Crystallization ages on biotite and hornblende from plutonic rocks range from about ~60 to ~63 Ma, while a sericite alteration age in plutonic rocks altered by a dike swarm also is around ~63 Ma. Sericite alteration associated with a copper-molybdenum porphyry ranges from ~10 to ~11 Ma. Analyses were performed by the University of Alaska Fairbanks Geochronology Laboratory, and results were reported by Paul Layer and Jeff Benowitz. This data release includes the following products: a summary of sample collection methods, the laboratory report, analytical data tables and associated metadata, and plots of the 40Ar/39Ar age spectra, Ca/K, and Cl/K ratios. All components of this data release are downloadable from the DGGS website at no charge. We selected samples for 40Ar/39Ar analysis to characterize and distinguish plutonic complexes and mineralization events, and to unravel the magmatic, structural, and metallogenic evolution of the area. The study area was selected primarily because it was located in the survey tracts with the largest number of plutons and volcanic rocks according to previous regional geologic mapping. The DGGS metadata standard extends the FGDC standard to include elements that are required to facilitate our internal data management. These elements, referred to as "layers," group and describe files that have intrinsic logical or topological relationships and correspond to subdirectories within the data distribution package. The metadata layer provides an FGDC metadata file and may include other documentation files. Attribute information for each data layer is described in this metadata file under the "Entity_and_Attribute_Information" section. Data layer contents: >border: Outline of the study area >arar-summary-data-locations: Identification numbers, coordinates, sample descriptions, and summary ages of each sample >step-heating-data: Power output levels and resultant measurements from each sample run 2013 ground condition complete None planned -153.320334 -153.022560 61.695701 61.541464 ISO 19115 Topic Category geoscientificInformation Alaska Division of Geological & Geophysical Surveys 40Ar/39Ar Age Dates Airborne Geophysical Survey Analyses and Sampling Analytical Results Ar-Ar Bedrock Geology Copper Economic Geology Faults Fracturing Geochronology Geology Gold Hornblende K-Feldspar Lab Methods Mica Mineral Deposit Mineral Prospect Mineralogy Minerals Mining Mining Claims Molybdenite Muscovite Ore Deposit Model Plutonic Rocks Plutons Polymetallic Vein Porphyry Pyrite Pyrrhotite Quartz Sample Location Sericite Sericite Alteration Volcanic Rocks Alaska Division of Geological & Geophysical Surveys Alaska Range Lime Hills Quadrangle Styx River Walker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of America Cretaceous Jurassic Miocene Tertiary 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). 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. Alaska Division of Geological & Geophysical Surveys GIS Manager mailing and physical

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Fairbanks AK 99709-3707 USA (907)451-5020 dggsgis@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays This project is funded through the Governor's Strategic and Critical Minerals Assessment Capital Improvement Project, a component of the ongoing Alaska Airborne Geophysical/Geological Mineral Inventory Program funded by the Alaska State Legislature and managed by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. Samples in this report were collected, described, logged, and prepared in part by Larry Freeman, David Reioux, Karri Sicard, Evan Twelker, Erik Bachmann, Amy Tuzzolino, and Alicja Wypych of DGGS and by Rainer Newberry of the University of Alaska Fairbanks Department of Geology & Geophysics. Sicard, K.R. Wypych, Alicja Twelker, Evan Bachmann, E.N. Freeman, L.K. Newberry, R.J. Reioux, D.A. Tuzzolino, A.L. Wright, T.C. 2014 Raw Data File RDF 2014-6 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 4 p http://dx.doi.org/10.14509/27289 Coordinates of sample locations were determined by the geologists in the field using handheld GPS units. Sample numbers were recorded in the field on sample bags and on field note sheets. The sample location table was cross checked for consistency against the sample numbers recorded on the bags. Laboratory sample numbers were generated by the UAF geochronology lab from the a list provided by DGGS. See text report for additional discussion of laboratory procedures. Lab results and interpretations were examined by the DGGS geologists to ensure that they are reasonable given the geologic context of the sample. not applicable Users should note that the interpretive summaries that are provided in the text report have been lightly edited for clarity but are generally provided as received from the lab. Locations were recorded using handheld, WAAS-enabled GPS devices. WAAS-enabled GPS devices have a reported error of about 1 m (NSTB/WAAS T&E Team, 2006). Depending on degradation of the WAAS and GPS signals, the horizontal position error of sample locations in this report is in the range of 1-10 m. Fieldwork - Field geologists (2013) collected rock samples from surface outcrops. Care was taken to collect fresh, unweathered samples displaying, when possible, sufficiently large grains for mineral separate sampling. 2013 Sample preparation and analysis - Prior to processing, thin sections of the samples were petrographically inspected to ensure that mineral specimens selected for dating were free of alteration. Rock samples that we found to be suitable for dating by 40Ar/39Ar geochronology analysis were submitted to the Geochronology Laboratory at the University of Alaska Fairbanks (UAF) where they were dated according to the protocols outlined in the accompanying report. 2013 The text and tables were revised to correct inconsistencies and to clarify reporting of the preferred ages. 2014 point 0.00001 0.00001 decimal degrees World Geodetic System of 1984 WGS 84 6378137 298.257223563 rdf2014-21-border.shp Outline of the study area Alaska Division of Geological & Geophysical Surveys border rdf2014-21v-1-0-1-arar-summary-data-locations.csv Identification numbers, coordinates, sample descriptions, and summary ages of each sample Alaska Division of Geological & Geophysical Surveys arar-summary-data-locations SAMPLE Label assigned in the field to identify the sample. Alaska Division of Geological & Geophysical Surveys Generic example of a sample identifier: YYAAA9999X: YY=last two digits of 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. LAB_SAMPLE_NUMBER Label used by the lab to identify the sample. Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The lab sample number is typically identical to the field sample number. However, in some cases, the sample number provided by the lab does differ from the number assigned in the field. We provide both numbers to document instances in which the sample numbers in the lab files differ from the field sample number. COLLECTOR The geologist who collected the sample. Alaska Division of Geological & Geophysical Surveys The samples presented in this report were collected by the authors or other DGGS staff. LONGITUDE Longitude, NAD27 Alaska Division of Geological & Geophysical Surveys 61.54146383 61.6957005 LATITUDE Latitude, NAD27 Alaska Division of Geological & Geophysical Surveys -153.3203343 -153.02256 MAP_UNIT The interpreted map unit of the sample. Alaska Division of Geological & Geophysical Surveys Map unit designations are based on geologic mapping described in: Gamble, B.M., Reed, B.L., Richter, D.H., Lanphere, M.A., 2013, Geologic Map of the East Half of the Lime Hills 1:250,000-scale Quadrangle, Alaska, U.S. Geological Survey Open-File Report 2013-1090. DESCRIPTION Description of the sample Alaska Division of Geological & Geophysical Surveys Characters 1 to 254 of a brief sample or station description. DESCRIP_2 Extension of the sample or station description for descriptions which are greater than 254 characters in length Alaska Division of Geological & Geophysical Surveys Characters greater than 254 of the sample or station description. NULL Blank (NULL) values indicate that the descriptive text is shorter than 254 characters. Alaska Division of Geological & Geophysical Surveys DATED_MATERIAL Indicates the type of material that was used for analysis Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The type of material that was selected for dating varied according to mineral composition and grainsize of the submitted rock sample. This field specifies whether the age was derived from a mineral separate (generally 1 to 10 individual crystals dated together as a single run), a single crystal, or the whole rock. MINERAL Indicates the mineral that was used for analysis Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The minerals selected for dating would typically be grains of biotite, hornblende, or muscovite. INTEGRATED_AGE_MA Integrated age and age error in million years Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The values are a concatenation of the integrated age determination and the calculated error associated with the integrated age determination PLATEAU_AGE_MA Plateau age and age error in million years Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The values are a concatenation of the plateau age determination and the calculated error associated with the plateau age determination NULL A NULL or blank values indicates that the PLATEAU_AGE_MA value was not calculated by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) PLATEAU_PERCENT_39AR Value in percent of the 39 Ar used in that portion of the spectrum to determine the plateau age Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 59.2 99.4 percent PLATEAU_MSWD The mean square weighted deviation of the plateau age calculation Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.46 2.02 NULL A NULL or blank values indicates that the value was not calculated by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) PLATEAU_REMARKS Comments and additional values that pertain to the plateau age determination method or interpretation. Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) Free text NULL A NULL or blank values indicates that the PLATEAU_REMARKS value was not provided by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) AVG_AGE_MA Weighted average age and age error in million years Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The values are a concatenation of the weighted average age determination and the calculated error associated with the weighted average age determination NULL A NULL or blank values indicates that the AVG_AGE_MA value was not calculated by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) AVG_AGE_MSWD The mean square weighted deviation of the weighted average age calculation Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 1.06 3.3 NULL A NULL or blank values indicates that the value was not calculated by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) AVG_AGE_REMARKS Comments and additional values that pertain to the weighted average age determination method or interpretation. Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) Free text NULL A NULL or blank values indicates that the AVG_AGE_REMARKS value was not provided by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) ISOCHRON_AGE Isochon age and age error in million years Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The values are a concatenation of the isochron age determination and the calculated error associated with the isochron age determination NULL A NULL or blank values indicates that the ISOCHRON_AGE value was not provided by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) ISOCHRON_MSWD The mean square weighted deviation of the isochron age calculation Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.44 2.08 NULL A NULL or blank values indicates that the value was not calculated by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) ISOCHRON_REMARKS Comments and additional values that pertain to the isochon age determination method or interpretation. Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) Free text NULL A NULL or blank values indicates that the ISOCHRON_REMARKS value was not provided by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) AGE_TYPE_PREFERRED Indicates AGE_TYPE_PREFERRED age. Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) A discussion of the preferred age for each analysis is provided in the accompanying lab report. The possible values are: plateau, isochron, weighted average, or integrated. PREFERRED_AGE The values are a concatenation of the preferred age determination and the calculated error associated with the preferred age determination Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The preferred age for each analysis is discussed in detail in the accompanying lab report. rdf2014-21-step-heating-data.csv Power output levels and resultant measurements from each sample run Alaska Division of Geological & Geophysical Surveys step-heating-data SAMPLE Label assigned in the field to identify the sample. Alaska Division of Geological & Geophysical Surveys Generic example of a sample identifier: YYAAA9999X: YY=last two digits of 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. LAB_SAMPLE_NUMBER Label used by the lab to identify the sample. Alaska Division of Geological & Geophysical Surveys and Geochronology Laboratory at the University of Alaska Fairbanks (UAF) The lab sample number is typically identical to the field sample number. However, in some cases, the sample number provided by the lab does differ from the number assigned in the field. We provide both numbers to document instances in which the sample numbers in the lab files differ from the field sample number. Laser_mW Laser output level in megawatts Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 400 9000 megawatts NULL A NULL or blank values indicates that the values in the row were calculated by weighting the individual heating steps by the fraction of 39Ar released. Geochronology Laboratory at the University of Alaska Fairbanks (UAF) Integrated We indicate whether the values in the row were derived from a heating step or calculated by weighting the individual heating steps by the fraction of 39Ar released. Alaska Division of Geological & Geophysical Surveys NULL The values in the row were derived from a heating step Geochronology Laboratory at the University of Alaska Fairbanks (UAF) Integrated the values in this row were calculated by weighting the individual heating steps by the fraction of 39Ar released Alaska Division of Geological & Geophysical Surveys Cum39Ar Cumulative ratio of 39Argon released at this step Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.0018 1 NULL A NULL or blank values indicates that the value was not applicable or not calculated by the lab Geochronology Laboratory at the University of Alaska Fairbanks (UAF) Me40Ar39Ar Measured 40Ar/39Ar ratio for each heating step, corrected for blank and 39Ar decay Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 1.88331 2598.32797 Er40Ar39Ar The one sigma error for each 40Ar/39Ar measurement Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00285 57.27692 Me37Ar39Ar The ratio of measured 37Ar to measured 39Ar for each heating interval for each sample corrected for blank and 37Ar and 39Ar decay Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00057 7.91884 Er37Ar39Ar The one sigma error for each 37Ar/39Ar measurement Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.0001 0.09869 Me36Ar39Ar Ratio of measured 36Ar to measured 39Ar for each step interval for each sample corrected for blank and 39Ar decay Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.0003 8.82769 Er36Ar39Ar The one sigma error for each 36Ar/39Ar measurement Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00003 0.19587 Atm40Ar Percent of 40Ar which is atmospheric in composition at each step level Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.79157 100.38463 ErAtm40Ar The one sigma error for the percent of 40Ar which is atmospheric in composition at each step level Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.07621 4.5863 MeCaK Ratio of Calcium to Potassium as determined from 37Ar/39Ar Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00105 14.6117 ErCaK The one sigma error for each Ca/K determination Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00018 0.18111 MeClK Ratio of Chlorine to Potassium as determined from 38Ar/39Ar Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00036 0.25661 ErClK The one sigma error for each Cl/K determination Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00001 0.01238 Er40ArRad39ArK One sigma error for each 40ArRad/39ArK value Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.00866 10.71373 AgeMa Calculated age for each temperature step for each sample Geochronology Laboratory at the University of Alaska Fairbanks (UAF) -60.76 102.7 MA ErAgeMa One sigma error of the age determination of each heating step Geochronology Laboratory at the University of Alaska Fairbanks (UAF) 0.06 60.36 MA WeightedAverageOfJFromStandards J value, calculated from the weighted average of standards placed in various positions in the nuclear reactor Geochronology Laboratory at the University of Alaska Fairbanks (UAF) WeightedAverageOfJFromStandards value and error Alaska Division of Geological & Geophysical Surveys mailing and physical

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Fairbanks AK 99709-3707 USA (907)451-5020 (907)451-5050 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays Please view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible. RDF 2014-21 v. 1.0.1 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. Contact DGGS for current pricing ASCII tabular files http://dx.doi.org/10.14509/29134 Free download 20141205 Alaska Division of Geological & Geophysical Surveys Metadata Manager mailing and physical

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Fairbanks AK 99709-3707 USA (907)451-5020 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys. http://www.dggs.alaska.gov/metadata/dggs.ext dggs metadata extensions