Table 1 Mineral composition of Da’anzhai shale.
Submember | Clay mineral (%) | Quartz (%) | Feldspar (%) | Calcite (%) | Dolomite (%) | Siderite (%) | Aragonite (%) | Pyrite (%) |
|---|---|---|---|---|---|---|---|---|
Upper | 27.6–56.8 (41.2) | 28.7–55.5 (41.3) | 0.8–2.3 (1.5) | 0.2–33.5 (41.2) | 0.2–3.2 (1.0) | 0.3–1.3 (0.7) | 0–3 (0.4) | 0.1–3.5 (1.0) |
Middle | 23.5–60.7 (46.3) | 10.1–41.1 (28.8) | 0.6–3.4 (1.9) | 0.4–50.3 (14.4) | 0–12 (1.2) | 0.3–2.6 (1.0) | 0–36.6 (1.8) | 0.6–4.9 (2.7) |
Lower | 6.5–40.9 (24.2) | 3.5–31.5 (21.3) | 0–1.6 (0.9) | 23.2–89.7 (50.3) | 0.3–0.7 (0.5) | 0–0.7 (0.4) | 0 | 0–2.7 (1.8) |
