Table T1. Secondary mineral assemblages of selected basalt samples, Holes U1346A and U1349A.
|
Core, section, interval (cm) |
Bottom depth (mbsf) |
Description | Alteration type | Identified minerals |
|---|---|---|---|---|
| 324-U1346A- | ||||
| 4R-1, 43–48 | 120.0 | Vesicular basalt | Green alteration | Celadonite + calcite + zeolite |
| 4R-2, 9–13 | 120.8 | Vesicular basalt | Green alteration | Celadonite + calcite + zeolite (heulandite series) |
| 6R-2, 5–10 | 140.4 | Highly vesicular basalt | Dark gray alteration | Hectorite/stevensite + calcite |
| 9R-2, 54–58 | 155.4 | Basalt | Brown alteration | Saponite/hectorite + kaolinite + calcite |
| 10R-1, 28–31 | 158.5 | Basalt | Brown alteration | Hectorite/stevensite + kaolinite + calcite |
| 11R-1, 53–56 | 163.6 | Basalt | Dark gray alteration | Saponite/hectorite/stevensite |
| 12R-1, 17.5–21.5 | 168.0 | Basalt | Dark gray alteration | Saponite/hectorite + montmorillonite |
| 16R-1, 36–39 | 187.4 | Basalt | Dark gray alteration | Saponite/hectorite + montmorillonite + calcite |
| 324-U1349A- | ||||
| 7R-3, 100–104 | 168.0 | Basalt | Red-brown alteration | Calcite* |
| 10R-1, 30–34 | 183.6 | Highly vesicular basalt | Red-brown alteration | Montmorillonite + nontronite + illite + calcite |
| 10R-3, 90–95 | 186.8 | Basalt | Red-brown alteration | Calcite* |
| 11R-2, 64–69 | 195.1 | Basalt | Red-brown alteration | Nontronite-illite mixed layers? + calcite |
| 12R-2, 39–43 | 204.4 | Vesicular basalt | Red-brown alteration | Calcite* |
| 12R-3, 71–75 | 206.1 | Basalt | Transition zone† | Saponite + montmorillonite + kaolinite + chlorite |
| 13R-5, 123–129 | 219.2 | Vesicular basalt | Transition zone | Hectorite + kaolinite + chlorite + calcite |
| 14R-1, 99–103 | 222.7 | Vesicular basalt | Transition zone | Stevensite + nontronite-chlorite mixed layers? + kaolinite + illite + calcite |
| 14R-3, 5–9 | 224.0 | Vesicular basalt | Transition zone | Hectorite/stevensite + nontronite-chlorite mixed layers? + kaolinite + illite + calcite |
| 14R-5, 9–13 | 226.9 | Vesicular basalt | Green alteration | Saponite/hectorite-chlorite mixed layers? + kaolinite |
| 15R-3, 21–26 | 233.8 | Vesicular basalt | Green alteration | Saponite/hectorite + kaolinite + chlorite + calcite |
| 15R-6, 18–24 | 238.1 | Basalt | Green alteration | Saponite/hectorite + montmorillonite + kaolinite |
* = no clay mineral could be identified either on bulk rock or oriented section XRD. † = sample is only slightly affected by alteration and a description of alteration better corresponds to transition zone alteration rather than red-brown alteration as initially described during IODP Expedition 324 (Expedition 324 Scientists, 2010a).