A2000b.
A fine-grained intersertal basalt containing plagioclase (laths; some areas showing directional flow patterns), opagues, clinopyroxene and possibly olivine. Phenocrysts/microphenocrysts are rare (in this slide and the following slides). However, microphenocrysts of opaques are scattered throughout the slide. Dark patches can be seen in this slide, probably indicating a glassy "mush". Some red staining isalso in this slide.
A2001a
A very fine-grained intersertal basalt containing needle-form plagioclase (some twinning can be seen), opaques and possibly clinopyroxene. Alight brownish mineral that is slightly pleochroic with sweeping extinction is dissemminated between the interstices of the other crystals. Microphenocrysts of opaques are present. There is reddish staining (in patches) through the rock.
A2002b
This is a fine-grained intersertal basalt composed of opaques. olivine. clinopyroxene and plagioclase. It contains "bands" of coarser-grained groundmass. These "bands" are lighter in color, indicating a higher concentration of plagioclase in the groundmass. This rock contains microphenocrysts of plagioclase (only two crystals). The light yellowish brown "mineral" with no extinction is glass.
A2003b
This is also a fine-grained intersertal basalt composed of plagioclase, opaques, olivine, and possibly clinopyroxene. no phenocrysts are present in this slide. However, some crystals in the groundmass may be transitional between groundmass and microphenocrysts. These crystals are mostly olivines with a few clinopyroxenes. The light yellow/brown "mineral" with no extinction is glass.
A2004b
This is a very fine-grained intersertal basalt composed of opaques, plagioclase, clinopyroxenes, and olivine (?) It contains one phenocryst of clinopyroxene (?) that is fractured and anhedral in form. The light yellow/brown "mineral" with no extinction is glass.
A2005b
This intergranular rock has subparallel flow pattern of the plagioclase. It also contains opaques and clinopyroxene, with some olivine. Phenocrysts of olivine and clinopyroxene are present. The phenocrystic clinopyroxene is darker colored than the olivine andcontains inclusions of opaques and glass concentrated in the centers (fuzzy-looking). Some reddish staining can be seen in this thin-section. This rock is coarser-grained than all others in this group.