| Unit/Subunit |
Core, section |
Depth (mbsf) |
Unit name | Thickness (m) | Lobe margins |
Grain size |
Groundmass |
Vesicularity (modal%) |
Average vesicle size (mm) |
Three-fold division |
Segregation structures |
Comments | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Curated
|
Cored
|
Simple
|
Glassy
|
Minerals
|
Texture
|
||||||||||
| 197-1204B- | |||||||||||||||
| 1 | 1R-3 | 814.03 | Aphyric basalt | 1.05 | 1.05 | L (2) | x (2) | fg/ap/G | pl, px, oq | 2-10 | 2 | Ucr | Olivine microphenocrysts; pseudomorphed by carbonate or Fe oxyhydroxide throughout the succession | ||
| 1 | 1R-4 | 814.75 | Aphyric basalt | 1.24 | 5.25 | L (1) | x (1) | fg/ap/G | pl, px, oq | 3 | 0.5 | Mai/Lcr | PV | Olivine and plagioclase microphenocrysts | |
| 1 | 2R-1 | 820.30 | Aphyric basalt | 1.30 | 1.30 | L (1) | x (1) | fg/ap/G | pl, ol, px, oq | 2-10 | 1 | Ucr/Mai | VC/HVS | Olivine and plagioclase microphenocrysts, part of upper vesicular crust and then massive interior of >5-m-thick lobe | |
| 1 | 2R-2 | 821.60 | Aphyric basalt | 1.34 | 1.34 | fg | pl, ol, px, oq | 2-10 | 1 | Mai | Olivine and plagioclase microphenocrysts, massive interior of ~5-m-thick lobe | ||||
| 1 | 2R-3 | 822.93 | Aphyric basalt | 0.87 | 0.87 | fg | pl, px | igr | 0-3 | 2 | Mai | Olivine and plagioclase microphenocrysts, massive interior of ~5-m-thick lobe | |||
| 1 | 2R-4 | 823.80 | Aphyric basalt | 1.36 | 1.36 | fg | pl, px | igr | 0-3 | 1 | Mai | Olivine and plagioclase microphenocrysts, massive interior of ~5-m-thick lobe. | |||
| 1 | 2R-5 | 825.15 | Aphyric basalt | 1.50 | 1.50 | L (1) | x (1) | fg/ap/G | pl, ol, px, oq | igr | 0-25 | 3 | Mai/Lcr | Olivine and plagioclase microphenocrysts; contains the massive interior of ~5-m- thick lobe | |
| 1 | 2R-6 | 826.67 | Aphyric basalt | 0.62 | 3.23 | L (1) | x (1) | ap/fg/G | pl, px, oq | igr | 4-15 | 2.0 | Ucr/Mai | Olivine microphenocrysts; section may represent a single lobe | |
| 1 | 3R-1 | 829.90 | Aphyric basalt | 1.45 | 1.45 | L (1) | fg | pl, ol, px, oq | igr | 15-35 | 2.0 | Olivine in groundmass (and as microphenocrysts); Sections 3R-1 and 3R-2 (<90 cm) may represent a single lobe (>2.4 m thick) | |||
| 1 | 3R-2 | 831.35 | Aphyric basalt | 1.50 | 1.50 | L (1) | x (1) | ap/G | pl, ol, px, oq | igr | 5-20 | 1.5 | Ucr/Mai/Lcr | PV | Olivine in groundmass (and as microphenocrysts); Section 3R-2 (>90 cm) through Section 3R-3 is one lobe |
| 1 | 3R-3 | 832.85 | Aphyric basalt | 0.30 | 6.75 | ap | pl, ol, px, oq | igr | 20.0 | 3.0 | Olivine in groundmass (and as microphenocrysts) | ||||
| 1 | 4R-1 | 839.60 | Aphyric basalt | 1.50 | 1.50 | L (5) | x (5) | fg/ap/G | pl, ol, px, oq | igr/ise-Va | 2-30 | 3.0 | Ucr/Mai/Lcr | VC | Olivine in groundmass (and as microphenocrysts) |
| 2a | 4R-2 | 841.10 | Aphyric basalt | 1.50 | 1.50 | L (4) | x (3) | fg/ap/G | pl, ol, px, oq | igr/ise-Va | 5-35 | 2.0 | Ucr/Mai/Lcr | PV/VC | Olivine in groundmass (and as microphenocrysts) |
| 2a | 4R-3 | 842.60 | Aphyric basalt | 0.52 | 6.70 | L (2) | x (2) | fg/ap/G | pl, ol, px, oq | igr/ise-Va | 5-35 | 2.0 | Olivine in groundmass (and as microphenocrysts) | ||
| 2a | 5R-1 | 849.30 | Aphyric basalt | 1.50 | 1.50 | L (2) | x (1) | fg/ap/G | pl, ol, px, oq | igr/ise-Va | 2-30 | 3.0 | Olivine in groundmass (and as microphenocrysts) | ||
| 2a | 5R-2 | 850.80 | Aphyric basalt | 1.34 | 7.80 | L (2-3) | fg | pl, ol, px, oq | igr | 2-30 | 4.0 | Ucr/Mai/Lcr | VC | Olivine in groundmass (and as microphenocrysts) | |
| 2a | 6R-1 | 858.60 | Aphyric basalt | 1.43 | 1.43 | L (2-4) | x (1) | fg/ap/G | pl, ol, px, oq | igr | 0-25 | 2.5 | Ucr/Mai/Lcr | Olivine in groundmass (and as microphenocrysts) | |
| 2a | 6R-2 | 860.03 | Aphyric basalt | 1.50 | 1.50 | L (3?) | fg | pl, ol, px, oq | igr | 0-25 | 2.5 | Ucr/Mai/Lcr | Olivine in groundmass (and as microphenocrysts) | ||
| 2a | 6R-3 | 861.53 | Aphyric basalt | 1.50 | 1.50 | L (6) | x (5) | fg/ap/G | pl, ol, px, oq | igr/ise-Va | 0-15 | 3.0 | VC | Olivine in groundmass (and as microphenocrysts); variolitic texture present near some lobe margins | |
| 2a | 6R-4 | 863.03 | Aphyric basalt | 0.98 | 5.17 | L (1) | fg/ap | pl, ol, px, oq | igr/ise-Va | 20.0 | 1.0 | Olivine in groundmass (and as microphenocrysts) | |||
| 2a | 7R-1 | 868.20 | Aphyric basalt | 1.49 | 1.49 | L (2-3) | fg/ap | pl, ol, px | igr | 5-15 | 1.5 | ||||
| 2a | 7R-2 | 869.69 | Aphyric basalt | 1.48 | 1.48 | L (2?) | fg/ap | pl, px, oq | igr/ise-Va | 7-8 | 2.0 | PV/VC | |||
| 2a | 7R-3 | 871.17 | Aphyric basalt | 1.25 | 6.63 | L | fg/ap | pl, ol, px, oq | igr/ise-Va | 3-25 | 3.0 | Ucr | This section contains the upper vesicular crust of Subunit 1b | ||
| 2b | 7R-3 | 872.42 | Diabase | 0.25 | 0.25 | S | mg | pl, ol, px, oq | igr | 3-25 | 3.0 | Mai | |||
| 2b | 8R-1 | 877.80 | Diabase | 1.50 | 1.50 | S | mg | pl, ol, px, oq | oph | 1-5 | 2.0 | Mai | |||
| 2b | 8R-2 | 879.30 | Diabase | 1.30 | 1.30 | S | mg | pl, ol, px, oq | oph | 1-4 | 2.0 | Mai | |||
| 2b | 8R-3 | 880.60 | Diabase | 1.32 | 6.25 | S | mg | pl, ol, px, oq | oph | 3-8 | 1.5 | Mai | |||
| 2b | 9R-1 | 887.10 | Diabase | 0.19 | 0.19 | S | mg | pl, ol, px, oq | oph | 1-5 | 1.5 | Mai | |||
| 2b | 9R-2 | 887.29 | Diabase | 1.40 | 1.40 | S | mg | oph | 1-5 | 1.5 | Mai | ||||
| 2b | 9R-3 | 888.69 | Diabase | 1.34 | 0.11 | S | mg | pl, ol, px | oph | 2-5 | 1.0 | Mai | |||
| 2b | 10R-1 | 888.80 | Diabase | 1.50 | 1.50 | S | mg | pl, ol, px | oph | 1-8 | 2.0 | Mai | |||
| 2b | 10R-2 | 890.30 | Diabase | 1.25 | 1.25 | S | mg | pl, ol, px | oph | 5.0 | 1.0 | Mai | |||
| 2b | 10R-3 | 891.55 | Diabase | 0.81 | 0.81 | S | mg | pl, ol, px, oq | oph | 2-7 | 1.0 | Mai | |||
| 2b | 10R-4 | 892.36 | Diabase | 1.45 | 4.24 | S | mg | pl, ol, px, oq | oph | 3-7 | 2.0 | Mai | |||
| 2b | 11R-1 | 896.60 | Diabase | 1.45 | 1.45 | S | mg | pl, ol, px | oph | 5-7 | 1.0 | Mai | |||
| 2b | 11R-2 | 898.05 | Diabase | 0.62 | 8.25 | S | mg | pl, ol, px, oq | oph | 3-6 | 1.5 | Mai | |||
| 2b | 12R-1 | 906.30 | Diabase | 1.40 | 1.40 | S | mg | pl, ol, px, oq | oph | 4-7 | 2.0 | Mai | |||
| 2b | 12R-2 | 907.70 | Diabase | 0.24 | 0.60 | S | mg | pl, ol, px, oq | oph | 1.0 | 1.0 | Mai | |||
| 2b | 13R-1 | 908.30 | Diabase | 1.47 | 1.47 | S | fg | pl, ol, px | igr | 3-8 | 1 | Mai | |||
| 2b | 13R-2 | 909.77 | Diabase | 1.39 | 1.39 | S | fg | pl, ol, px | igr | 1-10 | 0.5 | Mai | |||
| 2b | 13R-3 | 911.16 | Diabase | 1.17 | 1.17 | S | fg | pl, px, oq | igr | 5-8 | 2.0 | Mai | |||
| 2b | 13R-4 | 912.33 | Diabase | 0.91 | 3.57 | S | fg/mg | pl, px, clay | igr | ? | 0.5 | Mai | |||
| 2b | 14R-1 | 915.90 | Diabase | 1.12 | 1.12 | S | fg | pl, ol, px | igr | 0-5 | 0.5 | Mai | VC | Top of the basal crust for Subunit 1b | |
| 2b | 14R-2 | 917.02 | Diabase | 0.85 | 0.85 | S | fg/ap | pl, ol?, px | Va | 1-10 | 2.0 | Mai/Lcr | PV/VC | VCs contain spinifex-textured pyroxene; groundmass has high abundance of interstitial clay (after glass?) | |
| 2c | 14R-2 | 917.87 | Aphyric basalt (lobed) | 0.65 | 0.65 | L (1) | x (2) | ap | pl, px, ol | Va | 1-20 | 1.5 | Mai | VC | VCs contain spinifex-textured pyroxene |
| 2c | 14R-3 | 918.32 | Aphyric basalt (lobed) | 1.28 | 7.08 | L (1) | x (1) | fg/ap/G | pl, ol, px, oq | 2-25 | 2.0 | Mai | PV | ||
| 2c | 15R-1 | 925.60 | Aphyric basalt (lobed) | 1.44 | 1.44 | L (2) | x (1) | fg/ap/G | pl, ol, px, oq | Va | 5-30 | 2.5 | PV/VC | VCs contain spinifex-textured pyroxene | |
| 2c | 15R-2 | 927.04 | Aphyric basalt (lobed) | 1.50 | 1.50 | L (3?) | x (1) | fg/ap/G | pl, px, oq | igr/ise | 5-30 | 3.0 | VCs contain spinifex-textured pyroxene | ||
| 2c | 15R-3 | 928.54 | Aphyric basalt (lobed) | 0.88 | 6.66 | L (3) | x (2) | fg/ap/G | pl, px, oq | 5-30 | 3.0 | ||||
| 2d | 16R-1 | 935.20 | Hyaloclastite lapilli breccia | 5.10 | 9.70 | The lapilli breccia contains centimeter-sized fragments of small lobes (toes) enveloped by glassy selvage | |||||||||
| 3 | 17R-1 | 944.90 | Aphyric basalt (lobed) | 1.18 | 1.18 | L (2) | x (1) | fg/ap/G | pl, ol, px, oq | 5-25? | 1.5 | Ucr/Mai | |||
| 3 | 17R-2 | 946.08 | Aphyric basalt (lobed) | 1.10 | 1.10 | L (3) | x (4) | fg/ap/G | pl, ol, px, oq | 20-25 | 2.0 | ||||
| 3 | 17R-3 | 947.21 | Aphyric basalt (lobed) | 0.05 | 0.05 | L | x (1) | fg/ap/G | pl, ol, px, oq | 20.0 | 3.0 | Lcr | PV | Basal contact of unit; conformable, glassy lobe margins in direct contact with underlying sediment | |
| 4a-4d | 17R-3 | 947.26 | Clastic sediments | 1.40 | 7.30 | ||||||||||
Notes: L = lobe margins present within the section (number in parenthesis indicates number of lobes), S = simple lava in the sense that the section contains lava that is a part of a larger lobe, x = smooth-surfaced glassy lobe margins. Grain size: fg = fine grained, ap = aphanitic, G = glassy selvage (lobe margins), mg = medium grained. Groundmass minerals: pl = plagioclase, px = pyroxene, oq = opaque, ol = olivine. Groundmass texture: igr = intergranular, ise = intersertal, Va = variolitic, oph = subophitic to ophitic. Three-fold division: Ucr = upper crust, Mai = massive lob interior, Lcr = lower crust. PV = pipe vesicles, VC = vesicle cylinders, HVS = horizontal vesicle sheet.