Table T5. Summary of basement stratigraphy and subunits recovered in Hole 1383C.
| Lith. unit |
Subunit | Depth (m) | Core, section (Piece) |
Pieces in subunit (N) |
Lithology | Unit interpretation | Vesicularity | Groundmass alteration (%) |
Veins | Halos | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average density (vein/m) |
Average width (mm) |
Color | Average width (mm) |
|||||||||||
| Top | Bottom | Top | Bottom | |||||||||||
| 336-U1383C- | 336-U1383C- | |||||||||||||
| 1 | 1-1 | 69.51 | 87.53 | 2R-1 (1) | 4R-1 (15) | 105 | Aphyric to sparsely phyric | Pillow lava | Nonvesicular–sparsely vesicular (mean = 0.8%: max = 4%; size: 0.1–1 mm) | 1–40 (mean = 8) |
18 | 0.5 (max = 2) |
Dark brown–grayish brown | ~10 |
| 1 | 1-2 | 87.54 | 87.56 | 4R-1 (16) | 4R-1 (16) | 2 | Limestone | Interflow sediment | ||||||
| 1 | 1-3 | 87.78 | 88.47 | 4R-2 (3) | 4R-2 (10) | 7 | Sparsely phyric | Pillow lava | Nonvesicular–sparsely vesicular (mean = 0.5%: max = 2.7%; size: 0.1–1 mm) | 3–15 (mean = 8) |
24 | 0.5 (max = 1) |
Dark brown–grayish brown | ~8 |
| 1 | 1-4 | 88.48 | 88.54 | 4R-2A (11) | 4R-2A (11) | 1 | Limestone | Interflow sediment | ||||||
| 1 | 1-5 | 88.54 | 96.89 | 4R-2 (12) | 5R-1 (17) | 18 | Aphyric to sparsely phyric | Pillow lava | Nonvesicular–sparsely vesicular (mean = 0.5%: max = 3%; size: 0.1–1 mm) | 1–20 (mean = 8) |
16 | 0.4 (max = 1) |
Mainly grayish brown | ~12 |
| 1 | 1-6 | 96.90 | 96.93 | 5R-1A (18) | 5R-1A (18) | 1 | Limestone | Interflow sediment | ||||||
| 1 | 1-7 | 96.94 | 117.13 | 5R-1 (19) | 7R-2 (12) | 70 | Aphyric to sparsely phyric | Pillow lava | Nonvesicular–sparsely vesicular (mean = 0.5%: max = 4%; size: 0.1–0.8 mm) | 1–40 (mean = 8) |
24 | 0.5 (max = 5) |
Mainly grayish brown | ~15 |
| 1 | 1-8 | 117.14 | 117.30 | 7R-2A (13) | 7R-2A (14) | 2 | Sedimentary breccia | Interflow sediment | ||||||
| 1 | 1-9 | 117.30 | 126.52 | 7R-2 (15) | 8R-2 (6) | 37 | Aphyric to sparsely phyric | Pillow lava | Nonvesicular–sparsely vesicular (mean = 0.5%: max = 2%; size: 0.1–0.8 mm) |
3–40 (mean = 10) |
18 | 0.7 (max = 3) |
Mainly grayish brown with several composite dark and brown | ~15 |
| 1 | 1-10 | 126.52 | 126.55 | 8R-2A (7) | 8R-2A (7) | 1 | Sedimentary breccia | Interflow sediment | ||||||
| 1 | 1-11 | 126.55 | 126.72 | 8R-2 (8) | 8R-2 (10) | 3 | Aphyric to sparsely phyric | Pillow lava | Nonvesicular vesicular (<0.1%) | 25–30 | ||||
| 2 | 2-1 | 126.73 | 144.27 | 8R-2 (11) | 10R-1 (7) | 80 | Sparsely to highly phyric | Basalt flow/sheet flow | Nonvesicular–sparsely vesicular (mean = 0.7%: max = 4%; size: 0.1–1 mm) | 1–70 (mean = 8) |
15 | 0.2 (max = 1) |
Dark brown–grayish brown | ~13 |
| 2 | 2-2 | 144.28 | 144.38 | 10R-1A (8) | 10R-1A (9) | 2 | Sedimentary breccia | Interflow sediment | ||||||
| 2 | 2-3 | 144.38 | 145.89 | 10R-1 (10) | 10R-2 (8) | 20 | Sparsely to highly phyric | Basalt flow/sheet flow | Nonvesicular–sparsely vesicular (mean = 1.1%; max = 5%; size: 0.1–1 mm) | 2–20 (mean = 9) |
17 | 0.2 (max = 1) |
Dark brown–grayish brown | ~22 |
| 2 | 2-4 | 145.90 | 145.97 | 10R-2A (9) | 10R-2A (9) | 1 | Sedimentary breccia | Interflow sediment | ||||||
| 2 | 2-5 | 145.90 | 146.59 | 10R-2 (9) | 10R-2 (18) | 8 | Sparsely to highly phyric | Basalt flow/sheet flow | Nonvesicular–sparsely vesicular (mean = 0.7%: max = 3%; size: 0.1–1 mm) | 12–18 (mean = 15) |
27 | 0.5 (max = 2) |
Mainly grayish brown | ~33 |
| 2 | 2-6 | 146.61 | 146.62 | 10R-2A (19) | 10R-2A (19) | 1 | Sedimentary breccia | Interflow sediment | ||||||
| 2 | 2-7 | 146.63 | 153.96 | 10R-2 (20) | 11R-1 (8) | 33 | Sparsely to highly phyric | Basalt flow/sheet flow | Nonvesicular–sparsely vesicular (mean = 1%: max = 2%; size: 0.1–1 mm) | 2–25 (mean = 9) |
19 | 0.2 (max = 0.8) |
Mainly dark brown/green overlapping grayish brown | ~13 |
| 2 | 2-8 | 153.96 | 163.69 | 11R-1 (9) | 12R-1 (10) | 20 | Sparsely to highly phyric | Basalt flow/sheet flow | Nonvesicular–sparsely vesicular (mean = 0.9%: max = 3%; size: 0.1–1 mm) | 1–20 (mean = 7) |
18 | 0.3 (max = 2) |
Mainly dark green with minor grayish brown | ~20 |
| 2 | 2-9 | 163.69 | 163.72 | 12R-1A (11) | 12R-1A (11) | 1 | Sedimentary breccia | Interflow sediment | ||||||
| 3 | 3-1 | 163.72 | 163.80 | 12R-1A (12) | 12R-1A (13) | 2 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-2 | 163.80 | 164.26 | 12R-1A (14) | 12R-1A (24) | 10 | Aphyric | Pillow lava | Nonvesicular vesicular (<0.5%) | 2–4 (mean = 3) |
25 | 0.2 (max = 0.3) |
Mainly grayish brown | ~6 |
| 3 | 3-3 | 164.26 | 164.29 | 12R-1A (24) | 12R-1A (24) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-4 | 164.29 | 173.08 | 12R-1A (25) | 13R-1A (7) | 8 | Aphyric–sparsely phyric | Basalt flow/sheet flow | Nonvesicular vesicular (<0.5%) | 1–6 (mean = 3) |
45 | 0.2 (max = 0.5) |
Mainly dark brown–grayish brown | ~9 |
| 3 | 3-5 | 173.08 | 173.32 | 13R-1A (8) | 13R-1A (12) | 5 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-6 | 173.32 | 212.26 | 13R-1 (13) | 19R-1 (13) | 135 | Aphyric–sparsely/moderately phyric | Pillow lava | Nonvesicular–sparsely vesicular (mean = 0.6%: max = 3%; size: 0.1–0.8 mm) | 1–15 (mean = 5) |
27 | 0.2 (max = 0.6) |
Mainly grayish brown | ~11 |
| 3 | 3-7 | 212.26 | 212.30 | 19R-1A (14) | 19R-1A (14) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-8 | 212.30 | 219.35 | 19R-1 (15) | 20R-1 (3) | 21 | Aphyric | Pillow lava | Nonvesicular–sparsely vesicular (mean <0.5%: max = 3%; size: 0.1–0.8 mm) | 1–5 (mean = 3) |
27 | 0.2 (max 1) |
Mainly grayish brown |
~9 |
| 3 | 3-9 | 219.35 | 219.47 | 20R-1A (4) | 20R-1A (5) | 2 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-10 | 219.47 | 220.31 | 20R-1 (6) | 20R-1 (20) | 15 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | 1–5 (mean = 3) |
25 | 0.15 (max = 0.2) |
Mainly grayish brown |
~4 |
| 3 | 3-11 | 220.31 | 220.35 | 20R-1-A (21) | 20R-1A (21) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-12 | 220.35 | 220.38 | 20R-1-A (22) | 20R-1A (22) | 1 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | 2–5 (mean = 3) |
||||
| 3 | 3-13 | 220.38 | 220.47 | 20R-1-A (23) | 20R-1A (24) | 2 | Brecciated glassy basalt | |||||||
| 3 | 3-14 | 220.47 | 220.58 | 20R-1-A (25) | 20R-1A (26) | 2 | Aphyric | Pillow lava | Mainly nonvesicular (<0.5%) except with vugs up–2.8 mm | 2–5 (mean = 3) |
||||
| 3 | 3-15 | 220.58 | 220.66 | 20R-1-A (27) | 20R-1A (28) | 2 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-16 | 220.74 | 220.94 | 20R-2 (2) | 20R-2 (5) | 4 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | (mean = 3) | 45 | 0.2 (max = 0.5) |
None | NA |
| 3 | 3-17 | 220.94 | 220.99 | 20R-2-A (6) | 20R-2A (6) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-18 | 220.99 | 229.45 | 20R-2 (7) | 21R-1 (16) | 17 | Aphyric | Basalt flow/sheet flow | Nonvesicular–sparsely vesicular (mean <0.5%: max = 2%; size: 0.2–0.8 mm) | 1–4 (mean = 2) |
30 | 0.6 (max = 3) |
Mainly grayish brown |
~7 |
| 3 | 3-19 | 229.45 | 229.48 | 21R-1-A (17) | 21R-1A (17) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-20 | 229.48 | 237.93 | 21R-1 (18) | 22R-1 (5) | 13 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | 1–3 (mean = 2) |
40–50 | 0.2 (max = 0.6) |
None | NA |
| 3 | 3-21 | 237.93 | 237.98 | 22R-1-A (6) | 22R-1A (6) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-22 | 237.98 | 256.25 | 22R-1 (7) | 24R-1 (1) | 48 | Aphyric | Pillow lava | Nonvesicular–sparsely vesicular (mean <0.5%: max = 4%; size: 0.1–0.6 mm) | 1–10 (mean = 4) |
35 | 0.2 (max = 1) |
Mainly grayish brown |
~7 |
| 3 | 3-23 | 256.25 | 256.30 | 24R-1A (2) | 24R-1A (2) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-24 | 256.30 | 299.25 | 24R-1 (3) | 29R-1 (1) | 125 | Aphyric | Pillow lava | Nonvesicular–sparsely vesicular (mean <0.5%: max = 3%; size: 0.1–0.5 mm) | 1–15 (mean = 4) |
33 | 0.2 (max = 1) |
Mainly dark to grayish brown | ~7 |
| 3 | 3-25 | 299.25 | 299.29 | 29R-1A (2) | 29R-1A (2) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-26 | 299.29 | 312.18 | 29R-1 (3) | 31R-1 (2) | 58 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | 1–20 (mean = 5) |
38 | 0.3 (max = 1.5) |
Mainly dark to grayish brown |
~9 |
| 3 | 3-27 | 312.18 | 312.24 | 31R-1A (3) | 31R-1A (3) | 1 | Brecciated glassy basalt | Hyaloclastite | ||||||
| 3 | 3-28 | 312.24 | 324.12 | 31R-1 (4) | 32R-2 (17) | 79 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | 1–20 (mean = 5) |
33 | 0.3 (max = 3) |
Mainly dark to grayish brown |
~7 |
| 3 | 3-29 | 324.27 | 324.35 | 32R-3A (1) | 32R-3A (1) | 1 | Breccia | Pseudobreccia? | ||||||
| 3 | 3-30 | 324.35 | 324.76 | 32R-3 (2) | 32R-3 (9) | 8 | Aphyric | Pillow lava | Nonvesicular (<0.5%) | 1–5 (mean = 3) |
NA | |||
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