|
Core, section,
interval (cm) |
Description
|
Alteration
|
XRD identification
|
|---|---|---|---|
| 183-1136A- |
|
|
|
| 15R-2, 30-36 | Olivine-plagioclase glomerophyric basalt, vesicular (15%), incompletely crystallized, with intersertal texture. Phenocrysts (10%-15%) are tabular crystals of plagioclase (labradorite) with size 0.3-1.2 mm and single grains of olivine. Groundmass is plagioclase lathe, clinopyroxene, opaque minerals, and interstitial glass (10%-15%). | Moderate (~25%-30%); vesicles infilled with smectite and chlorite. Phenocrysts of olivine completely replaced by smectite and chlorite. Oxidation of basalt is low (~5%). | Smectite and hydromica in trace amounts |
| 16R-1, 113-118 | Sparsely plagioclase phyric basalt, vesicular (~8%). Groundmass demonstrates intergranular texture. Phenocrysts represented by tabular crystals of plagioclase (0.4- to 3-mm labradorite compose up to 5% of rock) and single grains of olivine. Groundmass is plagioclase lathe, clinopyroxene, single grains of olivine, opaque minerals and dust, and interstitial glass (5%-7%). | ~15%-20%; vesicles infilled with smectite and chlorite. Phenocrysts of olivine and interstitial glass completely replaced by smectite and chlorite. Oxidation of basalt is low (~3%-5%). | Smectite |
| 17R-2, 84-90 | Sparsely plagioclase phyric basalt, weakly vesicular (~5%; 0.08-0.15 mm), incompletely crystallized, with intergranular texture. Phenocrysts of tabular crystals of plagioclase (up to 1 mm) labradorite (~5% of rock). Groundmass is plagioclase lathe (45%-50%), clinopyroxene (30%-35%), opaque minerals (5%), and interstitial glass (10%). | ~15%; interstitial glass completely replaced by smectite and chlorite. Rock is nonoxidized. | Smectite |
| 18R-2, 62-67 | Plagioclase phyric basalt, vesicular (~10%), incompletely crystallized, with intersertal texture. Phenocrysts of tabular crystals of plagioclase (0.3-2.5 mm) labradorite (5%-10% of rock). Groundmass is plagioclase lathe (45%-50%), microlathe of clinopyroxene (30%-35%), opaque minerals (2%-3%), and interstitial glass (10%-15%). | ~15%-20%; vesicles infilled with smectite and chlorite; interstitial glass completely and partially replaced with smectite and chlorite. Rock is nonoxidized. | Smectite |
| 19R-1, 27-31 | Plagioclase phyric basalt, vesicular (~10%), incompletely crystallized, with interstitial texture. Sample is same as Sample 183-1136A-18R-2, 62-67 cm. | ~10%-15%. Rock is nonoxidized. | Smectite |
Note: XRD = X-ray diffraction.