Gossan & Iron Oxide Speciation
Hematite and goethite separated from each other, with the hydroxyl reading carried alongside as a ferric class.
Separates hematite from goethite, and reports the related iron-hydroxyl reading as a ferric class.
Iron ore workings. The layer separates hematite from goethite across ground like this.
WHAT THE SENSOR SEES
What this layer looks for.
The laboratory reference for each material, and what the sensor's band spacing captures of it. The shaded band marks the range the method reads.
WHAT IT FINDS
What it detects.
| Material | Typical setting | What can confuse it |
|---|---|---|
| Ferric hydroxyl class (jarosite is one candidate of roughly thirty) | Supergene capping over sulfide systems | Copper carbonates, opal and dolomite all pass this gate; organic soil flattens the curve |
| Hematite vs Goethite | Oxidized iron caps and leached zones | Atmospheric aerosols and dust haze |
METHOD
How it works.
Calibrated reflectance goes in, and every pixel is fitted against a public reference library.
Visible and infrared read at one product level
Both ranges are taken from the same surface reflectance product, so the ferric and hydroxyl readings sit on a common radiometric footing.
Iron absorption position fitting
Fits the iron absorption minimum, which sits in a different place for hematite than it does for goethite.
Iron-hydroxyl depth
A continuum-removed depth is computed on fixed shoulders. It is reported as a lumped ferric hydroxyl class, and no single mineral name is attached to it.
Ferric ratio mapping
Outputs the ratio between the hydroxyl class and the ferric oxides, which tracks how leached a cap looks.
SPECIFICATIONS
What you get, and what it runs on.
Conditions it needs
Method and checks are documented in Axine Applied Spectroscopy Paper #1 · Section 8.2.
Scope
Reads surface iron and its hydroxyl coatings, reported as a ferric class rather than a single named mineral.
RUN IT OVER YOUR GROUND
Run this layer over your own area.
Order processing over your area of interest, or a tasked capture where the archive has nothing usable. Imagery access is never charged for: a plan buys the models.
COMPLEMENTARY ANALYTICS
Related layers.
Alteration Mineral Mapping
Per-pixel alteration mineralogy separating advanced argillic, phyllic and propylitic assemblages.
Acid Drainage Screening
Screening for precipitate coatings along discharge channels, with a ferric floor gating the read.
Porphyry Cu-Au Vectoring
Vectors toward the hydrothermal centre by tracking how white mica composition shifts across the district.