Identification_Information :

    Citation :

      Citation_Information :

        Originator : Alberta Energy Regulator

        Originator : Alberta Geological Survey

        Originator : Chowdhury, S.

        Originator : Kelly, S.A.

        Publication_Date : 2024

        Title : Reflectance Spectra with Mineral Absorption Features from Outcrops of Canadian Shield Rocks in the Andrew Lake and Leland Lakes Area, Northeastern Alberta (tabular data, tab-delimited format)

        Geospatial_Data_Presentation_Form : tabular digital data

        Series_Information :

          Series_Name : Digital Data

          Issue_Identification : DIG 2024-0011

        Publication_Information :

          Publication_Place : Edmonton, Alberta, Canada

          Publisher : Alberta Geological Survey

        Online_Linkage : https://ags.aer.ca/publication/dig-2024-0011

    Description :

      Abstract : This dataset presents 523 spectral signatures, each detailed with absorption features—specific wavelengths at which minerals absorb light—collected using a handheld spectrometer (350 nm to 2500 nm) on outcrops of Canadian Shield rocks in the Andrew Lake and Leland Lakes area in northeastern Alberta. These absorption features are critical for identifying mineral compositions and provide insight into the unique properties of each mineral, such as crystallinity and composition. The dataset showcases a spectrum of mineral absorption features, including aluminum-iron-magnesium (Al-Fe-Mg), aluminum-hydroxide (Al-OH), chlorite spectral maturity (CSM), iron mineral intensity (Fe3i), iron mineral type (Fe3t), illite spectral maturity (ISM), kaolinite (Kx), iron-hydroxide (Fe-OH), and magnesium hydroxide (Mg-OH), with geographic coordinates for precise localization of the mineral outcrops. The mineral absorption feature dataset is accompanied by the spectral signature dataset in ASCII format for ENVI software compatibility. This collection can aid in the identification of minerals and the interpretation of geological processes. Notably, ninety-three percent of endmembers within a 20-metre radius of rocks with elevated concentrations of cerium (Ce), neodymium (Nd), praseodymium (Pr), lithium (Li), uranium (U), and thorium (Th)—as determined by whole-rock geochemical analysis—display four or more distinct absorption features. These are predominantly associated with primary lithologies such as gneiss, granitoid, mylonite, and diatexite, offering insights into the geological and mineralogical context of this area of the Canadian Shield.

This work was completed under the Mineral Grant provided by the Government of Alberta dated June 22, 2021.

October 10, 2024 Erratum: Errors were observed in the metadata document for this dataset. Those errors have been corrected.

      Purpose : To provide the results of a field study using reflectance spectroscopy to identify mineral outcrops potentially associated with critical minerals in the Andrew Lake and Leland Lakes areas of northeastern Alberta.

      Supplemental_Information : Language: In English;

    Time_Period_of_Content :

      Time Period Information :

        Single Date/Time :

          Calendar_Date : 202307

    Currentness_Reference : ground condition

  Status :

    Progress : Complete

    Maintenance_and_Update_Frequency : As needed

  Spatial Domain :

    Bounding Coordinates :

      West_Bounding_Coordinate : -112

      East_Bounding_Coordinate : -110

      North_Bounding_Coordinate : 60

      South_Bounding_Coordinate : 59

  Keywords :

    Theme :

      Theme_Keyword_Thesaurus : ISO 19115 Topic Category

      Theme_Keyword : critical minerals

      Theme_Keyword : geology

      Theme_Keyword : minerals

      Theme_Keyword : rare earth elements

      Theme_Keyword : reflectance spectroscopy

      Theme_Keyword : remote sensing

    Place :

      Place_Keyword_Thesaurus : ISO 19115 Topic Category

      Place_Keyword : 74m

      Place_Keyword : alberta

      Place_Keyword : canada

      Place_Keyword : canadian shield

      Place_Keyword : northeast alberta

  Access_Constraints : Public

  Use_Constraints : Acknowledgement of the Alberta Energy Regulator / Alberta Geological Survey as the originator / source of this information is required as described in the Open Government License - Alberta.

  Point_of_Contact :

    Contact_Information :

      Contact_Organization_Primary :

        Contact_Organization : Alberta Geological Survey

        Contact_Person : AGS Information Manager

      Contact_Position : AGS Information Manager

      Contact_Address :

        Address_Type : mailing and physical

        Address : Alberta Energy Regulator

        Address : 4th Floor, Twin Atria Building

        Address : 4999-98 Avenue NW

        City : Edmonton

        State_or_Province : Alberta

        Postal_Code : T6B 2X3

        Country : Canada

      Contact_Voice_Telephone : (780) 638-4491

      Contact_Facsimile_Telephone : (780) 422-1459

      Contact_Electronic_Mail_Address : AGS-Info@aer.ca

      Hours_of_Service : 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.

  Cross_Reference :

    Citation_Information :

      Originator : Alberta Energy Regulator

      Originator : Alberta Geological Survey

      Originator : Chowdhury, S.

      Originator : Kelly, S.A.

      Publication_Date : 2024

      Title : Mineral Absorption Feature Classification of Northeastern Alberta Using WorldView-3 Multispectral Imagery and Reflectance Spectra Collected in the Field (image data, GeoTIFF format)

      Geospatial_Data_Presentation_Form : raster digital data

      Series_Information :

        Series_Name : Digital Data

        Issue_Identification : DIG 2024-0012

      Publication_Information :

        Publication_Place : Edmonton, Alberta, Canada

        Publisher : Alberta Geological Survey

      Online_Linkage : https://ags.aer.ca

Data_Quality_Information :

  Attribute_Accuracy :

    Attribute_Accuracy_Report : Within a 20-metre radius of rocks that exhibit high levels of Ce, Nd, Pr, Li, U, and Th—as established through whole-rock geochemical analysis—93% of mineral spectra show four or more unique absorption features (refer to the cross-referenced geochemical data for further details).

Overall Accuracy = (40/(40+3)) 93%

Total Samples | Positive Predicted (PP) | Negative Predicted (PN)

Positive Actual (P) | True Positive (TP) = 40 | False Negative (FN) = 3

  Logical_Consistency_Report : The dataset has no null values.

  Completeness_Report : Only reflectance spectra with mineral absorption features were used in this dataset.

  Positional_Accuracy :

    Horizontal_Positional_Accuracy :

   Horizontal_Positional_Accuracy_Report : The latitude/longitude coordinates may exhibit a positional accuracy error of up to 2 metres.

    Vertical_Positional_Accuracy :

   Vertical_Positional_Accuracy_Report : n/a

  Lineage :

    Process_Step :

   Process_Description : Reflectance spectra were measured in the field using a handheld TerraSpec® Halo spectrometer. The device covers a spectral range from 350 nm to 1000 nm in the visible near-infrared (VNIR) region and from 1000 nm to 2500 nm in the short-wave infrared (SWIR) region. The spectral resolution of the device is approximately 3 nm in the VNIR range and about 10-12 nm in the SWIR range. A key feature of the TerraSpec® Halo is its integrated spectral library, which enhances the accuracy of mineral identification and provides scalar values for detailed analytical work (ASD Inc., 2018).

This section elaborates on the ASD TerraSpec® Halo spectra analysis methodology for identifying mineral absorption features in northeastern Alberta. A critical aspect of this analysis is the identification of minerals through the examination of absorption features in reflectance spectra. The diagnostic power of these features stems from their unique shapes and locations, which are influenced by specific chemical bonds or elements within a mineral's crystal lattice.

Hull Normalized Spectrum:

To enhance the visibility of absorption features, the device utilizes a hull normalized spectrum. This technique involves fitting a convex hull over the original reflectance spectrum and calculating the ratio of the original spectrum to this hull, effectively highlighting absorption features by removing the background continuum.

Scalar Analysis:

Scalars are essential parameters derived from the reflectance spectrum, offering insights into mineral properties such as crystallinity and composition. These scalars serve as indicators of various geochemical conditions and alteration events, providing valuable information beyond mere mineral identification.

Al-OH Scalar: Identifies aluminum-hydroxide (Al-OH) bond presence in minerals, indicating geochemical conditions during alteration events. It calculates the wavelength of the minimum reflectance within the 2160 to 2240 nm range, which is crucial for identifying minerals containing the Al-OH bond. Example applications include mapping white mica changes in hydrothermal systems, with systematic wavelength shifts serving as vectors to ore zones. Herrmann et al. (2001), Jones et al. (2005), and Harraden et al. (2013) have demonstrated the utility of the Al-OH scalar in identifying geochemical gradients and optimizing mineral processing design.

Kx Scalar: Reflects kaolinite crystallinity, which is used to distinguish kaolinite formed through weathering from that formed through alteration events. This scalar is the ratio of the reflectance values at 2160 nm and 2177 nm The distinction between weathering- and alteration-produced kaolinite has been widely applied in Australian geology due to the prevalence of low crystallinity kaolinite (Amera, 2007).

ISM (Illite Spectral Maturity) Scalar: Indicates the metamorphic grade of illite, with higher values suggesting higher alteration temperatures. This scalar's application extends to mapping thermal maturity in various geological settings. Doublier et al. (2010) and Guatame-Garcia (2013) have utilized ISM scalars in the evaluation of sedimentary basins and hydrothermal corridors. It is used in geological settings like thrust belts or sedimentary basins and uses the minimum reflectance values in two wavelength ranges (2240‒2270 nm and 1900‒2020 nm) to gauge the metamorphic grade of illite minerals.

CSM (Chlorite Spectral Maturity) Scalar: Similar to ISM, CSM tracks the metamorphic grade of chlorite minerals. Its utility is evident in distinguishing between chlorite minerals formed under different temperature conditions. Though specific case studies are fewer, the CSM scalar's conceptual application has been supported by Doublier et al. (2010), highlighting its potential in mapping metamorphic gradients.

Mg-OH and Fe-OH Scalars: Detect subtle compositional variations in minerals containing magnesium hydroxide (Mg-OH) and iron-hydroxide (Fe-OH) bonds, aiding in the delineation of ore horizons and mapping of alteration zones. The application of these scalars in studies by White et al. (2010) and Amera (2007) illustrates their effectiveness in tracking chlorite composition changes associated with mineralization. The Fe-OH scalar helps in mapping chlorite compositions in deposits and is similar to the Mg-OH index but targets the Fe-OH absorption feature within the 2240 to 2270 nm range.

Fe3t and Fe3i Scalars: Track the type and abundance of Fe+3 minerals, respectively. These scalars are crucial for identifying and mapping iron oxide deposits and for evaluating environmental conditions such as acid mine drainage. The work of Accame et al. (1983) and Anderson and Robbins (1998) has shown the significance of these scalars in environmental and mineral exploration studies. Fe3t is useful in mapping oxidized zones in deposits and identifies the minimum reflectance wavelength between 750 and 1000 nm, useful for differentiating iron oxide minerals. Fe3i is used to assess the abundance of Fe+3 minerals based on the intensity of their absorption feature using the ratio of reflectance at 742 nm to that at 500 nm.

Al-Fe-Mg Scalar: The aluminum-iron-magnesium (Al-Fe-Mg) scalar uses the relative depths of the Al-OH, Fe-OH, and Mg-OH absorption features to track geochemical conditions. It finds the minimum reflectance wavelength between 2160 and 2370 nm to help understand geochemical conditions . Its application in delineating geochemical gradients, as shown in the work of Amera (2007), underscores its utility in complex mineralogical investigations.

List of References:

Accame, G., Robinson, B. and Biehl, L. (1993): Iron oxide genesis and its influence on the spectral reflectance properties of gossans; LARS Technical Reports. Paper 68.

Amera, S.A. (2007): Spectral remote sensing of hydrothermal alteration associated with volcanogenic massive sulphide deposits, Gorob-Hope area, Namibia; M.Sc. thesis, International Institute for Geo-Information Science and Earth Observation (ITC), Enschede, The Netherlands, 54 p.

Anderson, J.E. and Robbins, E.I. (1998): Iron-oxide precipitates associated with acidic mine drainage; Photogrammetric Engineering & Remote Sensing, v. 64(12), p. 1201‒1208.

ASD Inc. (2018): TerraSpec Halo mineral identifier specifications; Retrieved from ASD Inc.

Doublier, M.P., Roache, A. and Potel, S. (2010): Application of SWIR spectroscopy in very low-grade metamorphic environments: a comparison with XRD methods; Geological Survey of Western Australia, Record 2010/7, 61 p.

Guatame-Garcia, L.A. (2013): Crystallinity variations of smectite-illite and kaolin hydrothermal alteration minerals by using SWIR spectroscopy – a study of the Rodalquilar Au-deposit, SE Spain; M.Sc. thesis, University of Twente Faculty of Geo-Information and Earth Observation (ITC), Enschede, The Netherlands, 84 p.

Harraden, C.L., McNulty, B.A., Gregory, M.J. and Lang, J.R. (2013): Shortwave infrared spectral analysis of hydrothermal alteration associated with the Pebble porphyry copper-gold-molybdenum deposit, Iliamna, Alaska; Economic Geology, v. 108(3), p. 483‒494.

Herrmann, W., Blake, M.D., Doyle, M.G., Huston, D.L., Kamprad, J., Merry, N. and Pontual, S. (2001): Short wavelength infrared (SWIR) spectral analysis of hydrothermal alteration zones associated with base metal sulfide deposits at Rosebery and Western Tharsis, Tasmania, and Highway-Reward, Queensland; Economic Geology, v. 96(5), p. 939‒955.

Hinchey, J.G. (2011): Visible/infrared spectroscopy (VIRS) of volcanogenic massive sulphide hydrothermal alteration products, Tulks Volcanic Belt, central Newfoundland: An additional exploration technique? Current Research - Newfoundland and Labrador Department of Natural Resources Geological Survey, Report 11(1), p. 97‒108.

Jones, S., Herrmann, W. and Gemmell, J.B. (2005): Short wavelength infrared spectral characteristics of the HW horizon: implications for exploration in the Myra Falls volcanic-hosted massive sulfide camp, Vancouver Island, British Columbia, Canada; Economic Geology, v. 100(2), p. 273‒294.

White, A.J.R., Robb, V.M., Robb, L.J. and Waters, D.J. (2010): Portable infrared spectroscopy as a tool for the exploration of gold deposits in tropical terrains: A case study at the Damang deposit, Ghana; Society of Economic Geologists Special Publication 15, p. 67‒84.

   Process_Date : 2023

  Data_Quality_Information :

Spatial_Data_Organization_Information :

Spatial_Reference_Information :

Entity_and_Attribute_Information : Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: DIG 2024-0011

Entity_Type_Definition: This dataset presents 523 spectral signatures, each detailed with absorption features - specific wavelengths at which minerals absorb light - collected using the TerraSpec Halo mineral identifier in the Andrew Lake and Leland Lakes area of Northeastern Alberta's Canadian Shield.

Entity_Type_Definition_Source: Alberta Geological Survey

Attribute:

Attribute_Label: File_Name

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: ENVI format spectral signatures are provided in the zip file (the wavelength unit in the file is nm). ENVI spectral signature file name.

Attribute:

Attribute_Label: Lat_NAD83

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Latitude in decimal degrees north, referenced to the NAD83 datum.

Attribute:

Attribute_Label: Long_NAD83

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Longitude in decimal degrees east, referenced to the NAD83 datum.

Attribute:

Attribute_Label: Date

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Acquisition date of the spectral signature from the mineral outcrop sample.

Attribute:

Attribute_Label: Al-Fe-Mg

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Presence of Aluminum-Iron-Magnesium (Al-Fe-Mg) absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Al-OH

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Presence of Aluminum-Hydroxide (Al-OH) absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: CSM

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Chlorite Spectral Maturity absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Fe3i

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Iron (Fe+3) mineral intensity absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Fe3t

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Iron (Fe+3) mineral type absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Fe-OH

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Presence of Iron Hydroxide (Fe-OH) absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: ISM

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Illite Spectral Maturity absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Kx

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Crystallinity of Kaolinite absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Mg-OH

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Magnesium Hydroxide (Mg-OH) bond absorption feature. 1 indicates its presence, 0 indicates its absense.

Attribute:

Attribute_Label: Publisher

Attribute_Definition_Source: Alberta Geological Survey

Attribute_Definition: Organization that published the dataset.

  Distribution_Information :

    Distributor :

      Contact_Information :

        Contact_Organization_Primary :

          Contact_Organization : Alberta Geological Survey

          Contact_Person : AGS Information Manager

        Contact_Position : AGS Information Manager

        Contact_Address :

          Address_Type : mailing and physical

          Address : Alberta Energy Regulator

          Address : 4th Floor, Twin Atria Building

          Address : 4999-98 Avenue NW

          City : Edmonton

          State_or_Province : Alberta

          Postal_Code : T6B 2X3

          Country : Canada

        Contact_Voice_Telephone : (780) 638-4491

        Contact_Facsimile_Telephone : (780) 422-1459

        Contact_Electronic_Mail_Address : AGS-Info@aer.ca

        Hours_of_Service : 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.

Distribution_Liability : The Alberta Energy Regulator / Alberta Geological Survey (AER/AGS) licenses this information under the Open Government License - Alberta. Any references to proprietary software in our documentation, and/or any use of proprietary data formats in our releases, do not constitute endorsement by the AER/AGS of any manufacturer's product.

  Metadata_Reference_Information :

    Metadata_Date : 20241010

    Metadata_Contact :

      Contact_Information :

        Contact_Organization_Primary :

          Contact_Organization : Alberta Geological Survey

          Contact_Person : AGS Information Manager

        Contact_Position : AGS Information Manager

        Contact_Address :

          Address_Type : mailing and physical

          Address : Alberta Energy Regulator

          Address : 4th Floor, Twin Atria Building

          Address : 4999-98 Avenue NW

          City : Edmonton

          State_or_Province : Alberta

          Postal_Code : T6B 2X3

          Country : Canada

        Contact_Voice_Telephone : (780) 638-4491

        Contact_Facsimile_Telephone : (780) 422-1459

        Contact_Electronic_Mail_Address : AGS-Info@aer.ca

        Hours_of_Service : 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.

    Metadata_Standard_Name : FGDC Content Standard for Digital Geospatial Metadata

    Metadata_Standard_Version : FGDC-STD-001-1998

    Metadata_Time_Convention : local time

    Metadata_Access_Constraints : none

    Metadata_Use_Constraints : none