Major oxide and trace element analyses for rock samples from the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
Major oxide and trace element analyses for rock samples from the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska
Abstract:
Major oxide and trace element analyses for rock samples from the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska, Raw Data File 2024-18, presents whole-rock and major- and trace-element geochemistry of rock samples collected to support geologic mapping in portions of the Skagway A-1, A-2, B-1, B-2, and B-3 15-minute quadrangles, an area of approximately 300 square miles. On December 2, 2020, a landslide triggered by an atmospheric river weather phenomenon at Beach Road in Haines, Alaska, claimed two lives. Numerous debris flows were also recorded around town during the same rain event, especially along Lutak Spur Road. As a response, the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project's goal is to create an updated 1:50,000-scale geologic map in paper and digital GIS formats. A comprehensive, detailed map constructed using modern analytical methods is critical to help land managers and residents make informed decisions when planning future development and evaluating risks to infrastructure. During July 2022, May 2023, and August 2023, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted fieldwork supporting surficial and bedrock mapping (Truskowski and others, 2024). This data file is released as a Raw Data File with an open end-user license. The data are available from the DGGS website: http://doi.org/10.14509/31286.
Supplemental_Information:
geochemistry-download:    Digital data available through the Alaska Geochemistry database online. Download files include data, analytical methods, and detection limits.
  1. How might this data set be cited?
    Truskowski, C.M., Gillis, R.J., Bull, K.F., and Regan, S.P., 2024, Major oxide and trace element analyses for rock samples from the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska: Raw Data File RDF 2024-18, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -135.743526
    East_Bounding_Coordinate: -135.057648
    North_Bounding_Coordinate: 59.409172
    South_Bounding_Coordinate: 58.841734
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2023
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: csv
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a point data set.
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is WGS84.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    geochemistry-download
    Digital data available through the Alaska Geochemistry database online. Download files include data, analytical methods, and detection limits. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS))

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?
    This report was funded by the USGS National Cooperative Geologic Mapping Program under STATEMAP award number G22AC00606, 2022, and the State of Alaska General Fund. The views and conclusions contained in this document are those of the authors. They should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey or by any branch or employee of the State of Alaska.
  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?

A comprehensive, detailed map constructed using modern analytical methods is critical to help land managers and residents make informed decisions when planning future development and evaluating risks to infrastructure. Major- and trace-element geochemistry for these rocks was analyzed to further our understanding of the resources in the area, including distinguishing between igneous and sedimentary protoliths for metamorphic rocks and characterizing and differentiating Mesozoic and Cenozoic magmatic events in the area.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 2023 (process 1 of 4)
    Field data collection - During July 2022, May 2023, and August 2023, DGGS and UAF geologists conducted fieldwork supporting surficial and bedrock mapping. Geologists collected representative rock samples for whole-rock major-oxide and trace-element geochemistry to aid in the classification of rock units, correlation of units over the map area, and understanding of the tectonic setting. They obtained sample locations using GPS-enabled tablets and smartphones running the Esri Field Maps App, which has a reported error of approximately 10 m. Latitude and longitude were reported using the WGS84 datum.
    Date: 2023 (process 2 of 4)
    Sample selection - Rock samples were collected for two different purposes. Visibly mineralized or altered rock samples were preferentially collected and analyzed for trace-element geochemistry. Additionally, igneous and metaigneous rocks showing little alteration or weathering were collected for whole-rock major-oxide, minor-oxide, and trace-element analyses to aid in the classification and study of petrogenesis and tectonic setting. Most samples are grab samples collected for their overall representation of the outcrop. However, as noted in the sample field description, a few are select samples more deliberately collected from a specific feature.
    Date: 2023 (process 3 of 4)
    Sample preparation - DGGS staff trimmed samples before submission for analysis to remove any weathering rind or altered areas. Bureau Veritas Commodities Canada Ltd. Mineral Laboratories (BV Mineral Laboratories) processed the samples using their PRP70-250 package. The samples were crushed to greater than 70 percent passing 2 mm, and a 250 g split was pulverized to greater than 85 percent passing through a 75-micron screen.
    Date: 2023 (process 4 of 4)
    Geochemistry - Major-oxide rock samples were analyzed by x-ray fluorescence (XRF) on a fused disc (BV Mineral Laboratories method XF700). A predetermined amount of sample is roasted to determine the loss on ignition (LOI). A second sample split is dried at 105 degrees C, and the sample is then fused in a platinum-gold crucible with a commercial lithium tetraborate flux. The molten material is cast in a platinum mold. The fused discs are analyzed by XRF. Trace elements, including rare-earth elements, were determined using lithium metaborate fusion (BV Mineral Laboratories method LF100). The prepared sample is mixed with LiBO2/Li2B4O7 flux, and the sample and crucibles are fused in a furnace. The cooled bead is dissolved in ACS-grade nitric acid and analyzed by ICP and/or ICP-MS. Ag, As, Au, Bi, Cd, Cu, Hg, Mo, Ni, Pb, Sb, Se, Tl, and Zn were determined by aqua regalia digestion and ICP-ES (BV Mineral Laboratories method AQ200). The prepared sample is digested with a modified Aqua Regia solution of equal parts concentrated HCl, HNO3, and DI H2O for one hour in a heating block or hot water bath. The sample is made up to volume with dilute HCl and then analyzed by ICP-ES. Total C and S were analyzed using IR Combustion (BV Mineral Laboratories method TC000) and are attributed to C and S occurring in all forms. Induction flux is added to the prepared sample and ignited in an induction furnace. A carrier gas sweeps up the released C and S, which are measured by adsorption in an infrared spectrometric cell. In addition to BV Mineral Laboratories' accredited (ISO/IEC 17025) internal quality-control program, DGGS monitored analysis quality with one reference-material standard per batch of 20 analyses.
  3. What similar or related data should the user be aware of?
    Larsen, M.C., Regan, S.P., Gillis, R.J., Nicolazzo, J.A., Darrow, M.M., Bull, K.F., Walser, S.L., and Truskowski, C.M., 2024, Geologic mapping and description of map units of the Haines-Takshanuk Mountains-Chilkat Peninsula area, Southeast Alaska: Preliminary Interpretive Report PIR 2024-9B, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Nicolazzo, J.A., Darrow, M.M., Larsen, M.C., and Walser, S.L., 2024, Rock strength properties of the Haines-Takshanuk Mountains-Chilkat Peninsula area statemap project, Southeast Alaska: Raw Data File RDF 2024-28, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Nicolazzo, J.A., Darrow, M.M., and Walser, S.L., 2024, Soil index properties and radiocarbon ages of the Haines-Takshanuk Mountains-Chilkat Peninsula area statemap project, Southeast Alaska: Raw Data File RDF 2024-27, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Truskowski, C.M., Walser, S.L., Larsen, M.C., Nicolazzo, J.A., Gillis, R.J., Bull, K.F., Regan, S.P., Darrow, M.M., and Montayne, Simone, 2024, Field station locations and data for the geologic map of the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska, collected in 2022 and 2023: Raw Data File RDF 2024-17, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p

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

  1. How well have the observations been checked?
    In addition to BV Mineral Laboratories' accredited (ISO/IEC 17025) internal quality-control program, DGGS monitored analysis quality with one reference-material standard per batch of 20 analyses.
  2. How accurate are the geographic locations?
    Location data were collected using GPS-enabled tablets and smartphones running the ESRI Field Maps App. Data were merged into an ArcGIS geodatabase. The devices have a reported error of about 10 m. Latitude and longitude are reported in the WGS84 datum.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This data releaase is complete.
  5. How consistent are the relationships among the observations, including topology?
    Not applicable

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? RDF 2024-18
  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: 11-Oct-2024
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 Fri Oct 11 19:29:36 2024