Identification_Information :

    Citation :

      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/publication/dig-2024-0012

    Description :

      Abstract : Reflectance spectra collected in the field were utilized to create a mineral absorption feature classification map using WorldView-3 multispectral imagery with 16 bands ranging from 425‒950 nm and 1210‒2330 nm. This map incorporates combinations of more than two absorption features: aluminum-iron-magnesium (AlFeMg), aluminum-hydroxide (AlOH), chlorite spectral maturity (CSM), iron mineral intensity (Fe3i), iron mineral type (Fe3t), illite spectral maturity (ISM), and magnesium hydroxide (MgOH). Such combinations can elucidate geological processes or environments, where the presence of specific features might indicate conditions like hydrothermal alteration, metamorphic grades, or particular mineralization processes. Classes with a higher number of features could provide a comprehensive insight into the geological and geochemical environment, essential for understanding complex deposits such as those containing REE, Li, and U/Th. This map aids in targeting exposed rocks with high-grade metamorphism for mineral exploration and sample collection, complementing geochemical analysis and geological mapping. Please note, this classification map only shows pure pixels of rock outcrop in the imagery by masking non-rock features such as vegetation/lichen, wetland, and shadows.

The mineral absorption feature classification raster contains 8 classes: 1 - AlFeMg-AlOH-CSM-Fe3i-Fe3t-ISM-MgOH, 2 - AlFeMg-AlOH-CSM-FeOH-ISM-MgOH, 3 - AlFeMg-AlOH-CSM-ISM-MgOH, 4 - AlFeMg-AlOH-CSM-MgOH, 5 - AlFeMg-AlOH-Fe3i-MgOH, 6 - AlFeMg-AlOH-FeOH-ISM, 7 - AlFeMg-AlOH-FeOH-MgOH, and 8 - AlFeMg-AlOH-ISM-MgOH.

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 : 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 : 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

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 by whole-rock geochemical analyses—79% of mineral spectra show four or more unique absorption features.

Overall Accuracy = (53/(53+14)) 79%

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

Positive Actual (P) | True Positive (TP) = 53 | False Negative (FN) = 14

  Logical_Consistency_Report : The datasets are in GeoTIFF format that have no null values.

  Completeness_Report : All pixels in the Worldview-3 cloud-free imagery were used for mineral absorption feature mapping.

  Positional_Accuracy :

    Horizontal_Positional_Accuracy :

   Horizontal_Positional_Accuracy_Report : This dataset has 1.84 m spatial resolution, which is the same as that of the WorldView-3 multispectral dataset.

    Vertical_Positional_Accuracy :

   Vertical_Positional_Accuracy_Report : n/a

  Lineage :

    Process_Step :

   Process_Description : Process steps to produce this map were performed in Google Earth Engine.

1. In this study, we isolated pure pixels of rock outcrop in the WorldView-3 imagery by masking non-rock features such as vegetation, wetland, and shadows. This was done using the Normalized Difference Vegetation Index (NDVI), shadow index, and burn index as described in Rivard (2023). This was crucial for accurately identifying mineralogical anomalies.

2. Out of 629 TerraSpec Halo mineral spectra collected in the summer of 2023 (see AGS Digital Data 2024-11), 8 unique endmember spectra were selected using Spectral Feature Fitting (SFF) and Spectral Angle Mapper (SAM) with a combination of more than two absorption features: AlFeMg, AlOH, CSM, Fe3i, Fe3t, ISM, and MgOH (Kruse et al., 1993; Clark et al., 1993; Baldridge et al., 2009).

3. The endmember spectra were then resampled to WorldView-3 VNIR (425 to 950 nm) and SWIR (1210 to 2330 nm) bands.

4. These resampled endmembers facilitated the generation of a spectral similarity map using SAM (threshold <0.15 radians) and primarily targeting spectral shape and the depth of absorption features.

References:

Rivard, B. (2023): Analysis of WorldView-3 satellite imagery for the Leland Lakes area, Alberta; Alberta Energy Regulator / Alberta Geological Survey, AER/AGS Special Report 116, 23 p.

Baldridge, A., Hook, S., Grove, C. and Rivera, G. (2009): The ASTER spectral library version 2.0; Remote Sensing of Environment, v. 113(4), p. 711‒715.

Clark, R., Swayze, G. and Gallagher, A. (1993): Mapping minerals with imaging spectroscopy; U.S. Geological Survey, Office of Mineral Resources Bulletin 2039, p. 141‒150.

Kruse, F.A., Lefkoff, A.B., Boardman, J.W., Heidebrecht, K.B., Shapiro, A.T., Barloon, P.J. and Goetz, A.F.H. (1993): The spectral image processing system (SIPS)‒interactive visualization and analysis of imaging spectrometer data; Remote Sensing of Environment, v. 44(2‒3), p. 145‒163.

   Process_Date : 2023

  Data_Quality_Information :

Spatial_Data_Organization_Information :

Spatial_Reference_Information :

Entity_and_Attribute_Information :

  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