Regional scale exploration targeting with ASTER

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PhotoSat offers a geological alteration mapping package produced using ASTER satellite photos.  In areas of sparse vegetation, ASTER photos are used to map silica, clay, ferric and hydrous ferric iron oxide, mica and propylitic minerals for epithermal gold and silver and porphyry copper exploration.

ASTER ALTERATION MINERAL MAPPING

Depending on the presence of the alteration minerals and photo visible outcrops the PhotoSat ASTER alteration mineral mapping will include the following:

All Silica

Hydroxyl1 alteration: Intensity

Alunite² alteration

Kaolinite³ alteration

Sericite4 alteration

Propylitic5 alteration

Hydrous Ferric Iron Oxide6 alteration

Ferric Iron Oxide7 alteration

Ferrous Iron8

ASTER context images

Geology enhanced colour image

Vegetation intensity

Greyscale image

¹ Minerals with OH bonds such as: alunite, sericite, kaolinite, dickite, illite, and montmorillonite

² Alunite or other minerals with an absorption peak at 2.2 microns

³ Kaolinite or other minerals with an absorption peak at 2.16 microns

4 Sericite is not a specific mineral. It is hydrothermal alteration of orthoclase or plagioclase feldspars.  It may consist of each, or a combination of, Muscovite, Illite, and Paragonite.  ASTER cannot differentiate between these micas.

5 Propylitic alteration includes carbonate, epidote, and chlorite

6 Goethite and/or Jarosite

7 Hematite

8 This may include any or all of the minerals actinolite, chlorite, ankerite, pyroxene, olivine, ferroan dolomite and siderite.

Deliverables:  All alteration minerals as RGB Geotiff files blue=possible, red=probable.

Shapefile polygons of probable areas for all alteration minerals

ASTER alteration mapping report

ADVANCED PRODUCTS:

Spectral matching: Spectral matching uses the spectral signature of a pixel to look for other similar pixels. If there is an outcrop of significant interest, we can analyze the spectral signature of a pixel related to that outcrop and provide a map of other pixels in the ASTER scenes that are similar. We can work with only the exact location of the outcrop.  It is best if you can provide photographs and a detailed geologic description of the outcrop.

Lithological enhancement: Lithological enhancement is a statistical analysis of the spectral signature that reveals the strongest spectral differences over the visible, near infrared and shortwave infrared bands. Outcrops and soil will show differences in lithology, while vegetated areas will just show the differences in vegetation.  The process works best when there is a significant amount of soil and/or rock exposure.

ASTER ALTERATION mineral mapping PRICING

The alteration mapping data is provided on a project-by-project basis. Please provide us with the extents of your project area and we will prepare a quote.

For more information contact us at info@photosat.ca or 1-604-681-9770.

 


 

PhotoSat ASTER Alteration Deliverables

Up to 9 orthorectified alteration images:

  • All Silica
  • Hydroxyl1alteration: Intensity
  • Alunite² alteration
  • Kaolinite³ alteration
  • Sericitealteration
  • Propyliticalteration
  • Hydrous Ferric Iron Oxide6alteration
  • Ferric Iron Oxide7alteration
  • Ferrous Iron8

3 Context images:

  • Geology enhanced colour image
  • Vegetation intensity
  • Greyscale image

Up to 9 ESRI Shapefiles (polygon):

  • All Silica
  • Hydroxyl1alteration: Intensity
  • Alunite² alteration
  • Kaolinite³ alteration
  • Sericite4alteration
  • Propylitic5alteration
  • Hydrous Ferric Iron Oxide6alteration
  • Ferric Iron Oxide7alteration
  • Ferrous Iron Oxide8 alteration

 

PhotoSat ASTER Alteration Technical Specifications

Scene Dimensions: ~60km x 60km
Map Projection: UTM, Others on request
Datum: WGS84, NAD27, NAD83 – Others on request
Raster Format: Alteration and Colour Images: GeoTIFF
Vector Format: Alteration minerals: ESRI Shapefiles (polygon)
Pixel Size: Color =12.5m, alteration=12.5m, silica=75m
Media: FTP

 

Image Resolution Pixel Size
Ferric Iron Oxide7 alteration

Geology enhanced colour image

Vegetation intensity

Greyscale image

15m 12.5m
Hydroxyl1 alteration: Intensity

Hydroxyl alteration: Alunite² to Kaolinite³

Sericite4 alteration

Propylitic5 alteration

Hydrous Ferric Iron Oxide6 alteration

Ferrous Iron8

30m 12.5m
Silica Zones 90m 75m

 

License Agreement

  • PhotoSat General Terms of Sale