Prograde and retrograde stages (skarn)
The two main stages of a skarn. In the hot prograde stage (often 400 to 650 °C), anhydrous garnets and pyroxenes form; in the retrograde stage, on cooling, they are replaced by hydrous minerals with sulfides, and this is often where most of the ore is deposited.
Composition
Prograde: garnet, pyroxene, wollastonite; retrograde: actinolite, epidote, chlorite, calcite, quartz, scheelite or sulfides.
Sources
In the atlas
- Luziyuan China
- Yangla China
- Watershed Australia
- Los Santos Spain
- Nanyangtian China