Table 2. Three Stages of Shale Weight Loss with the Evolution of Temperature.
| stages | temperature (°C) | decomposed matters of shale rocks |
|---|---|---|
| I | <400 | moisture and interlayer water of clay minerals |
| II | 400–600 | siderite, kerogen, pyrite, and structural water |
| III | >600 | carbonate minerals (calcite, dolomite, and ankerite) |