Pyrite heating under reducing

Figure 6. Pure Pyrites Heated Under Reducing Conditions to 600, 800, and 1000 °C. Reproduced with permission from reference 19. Copyright 1984 VGB.

The lower assemblage consists predominantly of red mudstone, with narrow sections (5-20 cm) of reduction spots and entire sections (0.5 to 2 m) of grey reduced and pyritic mudstone becoming more common towards the base. Narrow (0.5 to 5 m) intermediate extrusive volcanic flows become more common towards the base of this assemblage, and display basal textures indicating that moisture and mudstone rip-clasts were acquired into the flow and that heat was supplied to the underlying mudstones, which produced narrow (< 5 cm) contact metamorphism bands of re crystallized mudstone. 

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