| Unit number | Rock type | Drilled thickness (m) | Pillow margins | Massive interiors | Thin
sections (183-1140A-) |
|||
|---|---|---|---|---|---|---|---|---|
| Phenocrysts | Phenocrysts | Groundmass | Texture | |||||
|
1
|
Aphyric basalt* | 17.6 | 1%-5% PL | <1% PL | PL, CPX, OL, | Ophitic, intersertal, hypohyaline | 26R-1, 5-8 cm; 26R-1, 84-86 cm; | |
|
|
0%-5% OL | <1% OL | OPQ, GL | 27R-2, 0-5 cm; 27R-5, 10-12 cm; 28R-3, 29-32 cm | ||||
|
|
||||||||
|
2
|
Porphyritic basalt | 19.3 | <17% PL | PL, CPX, OL, | Glomeroporphyritic with intersertal or hypohyaline groundmass | 31R-1, 53-57 cm; 31R-2, 16-20 cm | ||
|
|
<4% CPX | OPQ, GL | ||||||
|
|
<3% OL | |||||||
|
3
|
Aphyric basalt | 10.3 | <1% PL | PL, CPX, OL, | Ophitic, intersertal, hypohyaline | 32R-1, 58-60 cm | ||
|
|
<1% OL | OPQ, GL | ||||||
|
4
|
Dolomite | 1.3 | ||||||
|
5
|
Porphyritic basalt | 14.3 | <10% PL | PL, CPX, OL, | Ophitic, intersertal, hypohyaline | 33R-2, 78-81 cm | ||
|
|
<1% OL | OPQ, GL | ||||||
|
6
|
Porphyritic basalt† | 23.9 | <7% PL | <8% PL | PL, CPX, OPQ, | Glomeroporphyritic with intergranular, intersertal or hyalopilitic groundmass | 34R-5, 3-6 cm; 35R-4, 49-50 cm; | |
| <8% CPX | 0%-4% CPX | GL, OL | 36R-3, 119-121 cm; 36R-4, 86-89 cm; | |||||
| <1% OL | 37R-1, 46-49 cm; 37R-3, 104-107 cm | |||||||
Notes: * = porphyritic in the pillow margins; † = the proportion of phenocrysts decreases downward and the basalt becomes locally aphyric. PL = plagioclase, CPX = clinopyroxene, OL = olivine, OPQ = opaque minerals (dominantly titanomagnetite), GL = glass.