| Unit/Subunit | Rock type | Drilled thickness (m) |
Characteristics | Major phases | Minor phases | Core,
section, interval (cm) |
Figure number* |
|---|---|---|---|---|---|---|---|
| 1A | Rhyolite cobbles |
29.06
|
Massive and flow-banded | Sanidine
(2%), lithic clasts (20%) |
Quartz,
biotite titanomagnetite altered amphibole |
51R-1, 3-551R-1, 23-25 | |
| 1B | Bioclastic sandstone |
0.47
|
|||||
| 1C | Felsic pumice breccia |
8.36
|
Pumiceous and flow banded | Glass (100%) | 52R-1, 120-123 | ||
| 1D | Perlitic felsic glass with lithics |
8.95
|
Perlitic texture | Glass (98%), alkali feldspar (2%) | 53R-1, 127-130 | F45 |
|
| 1E | Volcaniclastic
rocks |
9.60
|
Sheared and altered (fault zone) | ||||
| 2 |
Moderately sanidine- quartz-phyric rhyolite |
10.48
|
Vesicular, welded | Sanidine
(8%), quartz (1%) |
56R-1, 37-40 | F46A | |
| 3 |
Highly altered crystal vitric tuff-breccia |
9.74
|
Highly altered | Perlitic glass (76%), alkali feldspar (15%), quartz (4%) | Altered mafic mineral | 56R-3, 93-97 | F47 |
| 4 |
Moderately to highly sanidine-quartz-phyric rhyolite |
30.99
|
Vesicular, welded, spherulitic | Sanidine
(10%-15%), quartz (5%-10%) |
Quartz, titanomagnetite |
57R-1, 120-123 | F46B |
| 5 |
Moderately sanidine-phyric trachyte |
17.40
|
Altered; brecciated and massive | Sanidine (5%) | Clinopyroxene, titanomagnetite, quartz, plagioclase |
60R-2,
100-10461R-1,
74-76 |
F48A, F48B |
| 6 |
Aphyric trachybasalt |
19.30
|
Altered; brecciated and massive | Sanidine xenocrysts (<1%) | Plagioclase, sanidine, titanomagnetite | 62R-2, 117-119 | |
| 7 |
Aphyric
basaltictrachyandesite |
2.94
|
Crystal-rich sand at top contact | Sanidine xenocrysts (<1%) | Plagioclase, clinopyroxene, titanomagnetite | 64R-1,
38-43,64R-1,
81-84 |
F49A, F49B F51A |
| 8 |
Aphyric trachybasalt |
6.76
|
Altered; brecciated and massive | Sanidine xenocrysts (<1%) | Plagioclase, clinopyroxene, titanomagnetite | 64R-4, 77-78 | |
| 9 |
Aphyric trachybasalt |
1.76
|
Altered; brecciated and massive | Sanidine xenocrysts (<1%) | Plagioclase, clinopyroxene, titanomagnetite | 65R-2, 15-1965R-2, 29-30(basalt + xenolith) | |
| 10 |
Sparsely plagioclase-phyric trachybasalt |
2.54
|
Altered; trachytic groundmass texture: Carlsbad twinned feldspar | Plagioclase (1%), sanidine xenocrysts (<1%) | Clinopyroxene, titanomagnetite | 65R-3,
16-1865R-3,
90-93 |
F53A, F53B |
| 11 | Aphyric trachybasalt |
6.78
|
Trachytic groundmass texture | Sanidine xenocrysts (<1%) | Plagioclase, clinopyroxene, titanomagnetite | 65R-5,
49-5365R-5,
81-85 |
|
| 12 |
Aphyric trachybasalt |
3.03
|
Brecciated and massive; trachytic groundmass texture | Sanidine xenocrysts (<1%) | Plagioclase, clinopyroxene, titanomagnetite | 66R-3, 44-47 | |
| 13 | Aphyric
trachybasalt |
5.09
|
Altered; brecciated and massive | Sanidine xenocrysts (<1%) | Plagioclase, clinopyroxene, titanomagnetite | 66R-7, 5-8 | F51B |
| 14 | Basaltic Trachyandesite |
9.50
|
Brecciated and massive; trachytic groundmass texture | Plagioclase (2%), sanidine xenocrysts (<1%) | Olivine, clinopyroxene, titanomagnetite | 67R-5,
100-10367R-3,
109-111 |
F50 |
| 15 | Sparsely plagioclase-phyric basaltic trachyandesite |
5.16
|
Trachytic groundmass texture | Plagioclase (1%); sanidine xenocrysts (<1%) | Clinopyroxene,
titanomagnetite |
68R-4, 42-45 | |
| 16 |
Aphyric basaltic trachyandesite |
2.85
|
Altered; brecciated and massive | Alkali feldspar xenocrysts (<1%) | Plagioclase, altered mafic mineral, magnetite | 68R-6,
54-57 |
F52 |
| 17 |
Sparsely plagioclase-phyric basaltic trachyandesite |
10.89
|
Altered; brecciated and massive | Plagioclase (1%); sanidine xenocrysts (<1%) | Clinopyroxene titanomagnetite sulfide | 69R-2, 1-4 | |
| 18 | Moderately sanidine-phyric trachyandesite |
12.90
|
Altered | Sanidine (5%-10%) | Titanomagnetite, altered mafic mineral, plagioclase, sulfide, secondary siderite | 70R-1, 17-2070R-2, 141-14570R-3, 64-6871R-1, 0-671R-3, 63-6671R-4, 7-10 | F54 F55A F56A, F58 F59A, F59B |
| 19 | Moderately sanidine-phyric trachyte |
19.80
|
Altered | Sanidine (8%-15%) | Altered mafic mineral, titanomagnetite, plagioclase, secondary siderite | 71R-4, 134-13571R7, 24-2572R2, 57-6073R-3, 37-39 | F55B F56A, F57B F60 |
Note: * = Correlating figures in the "Site 1139" chapter.