"168-1023A-22X-CC (Piece 4, 034-040 cm)"						
ROCK NAME:	Sparsely to moderately plagioclase-olivine phyric basalt					
GRAIN SIZE:	Aphanitic: microcrystalline to cryptocrystalline					
TEXTURE:	Variolitic to subvariolitic; hypocrystalline					
PRIMARY MINERALOGY	PERCENT PRESENT	PERCENT ORIGINAL	SIZE (mm)	COMPOSITION	MORPHOLOGY	COMMENTS
PHENOCRYSTS						
Olivine	0.6	0.6	0.1-0.4		Euhedral-subhedral	"Individual crystals or intergrown with plagioclase. Skeletal, hollow crystals. Clear glass inclusions with shrinkage bubbles are common."
Plagioclase	3.8	3.8	0.3-1.7		Euhedral to subhedral laths	"Present as individual crystals and in monomineralic glomeroporphyritic clusters. Some exhibit simple to oscillatory zoning. Pale green or brown glass inclusions in the core of some, whilst others contain very fine opaque grains."
GROUNDMASS						
Plagioclase	3.8	3.8	<=0.2		Microlitic laths	Skeletal crystals (swallowtail and hollow forms). 
Olivine	1.8	1.8	<=0.3		Euhedral to subhedral	See comments above.
Clinopyroxene	Tr	Tr	<=0.3		"Granular, anhedral"	May be present as granular grains intergrown with plagioclase microlites; grains too small to determine optically.
Mesostasis	87.8	87.8				"Changes from dark brown subvariolitic, to a brown plumose to sheaf-spherulitic, to dark gray-brown intersertal texture with increasing distance from the chilled margin. Abundance of microlites and microphenocrysts increases with these zones. "
Glass	1.6	1.6				Clear <=1.5mm thick glass margin containing discrete varioles centered around plagioclase microlites and pyroxene microphenocrysts.
Pyrite	Tr	Tr	<=0.01		Granular	Very minor pyrite blebs (5 microns) in groundmass and in plagioclase microlites. Very minor submicron magnetite grains distributed throughout the groundmass.
Chalcopyrite	Tr	Tr	<=0.02		Granular	In mesostasis.
SECONDARY MINERALOGY	PERCENT	REPLACING/ FILLING				COMMENTS:
Saponite	Tr	Vesicles				Forms an inner lining of some vesicles.

VESICLES/ CAVITIES	PERCENT	DISTRIBUTION	SIZE (mm)	FILLING	SHAPE	COMMENTS:
Vesicles	0.6	Even	0.05-0.16	Partial		Partially lined by saponite.

COMMENTS:	Very fresh basalt.					

"168-1023A-22X-CC (Piece 6, 034-040 cm)"						
ROCK NAME:	Sparsely to moderately plagioclase-olivine-phyric basalt					
GRAIN SIZE:	Aphanitic: microcrystalline to cryptocrystalline					
TEXTURE:	"Variolitic, hypocrystalline"					
PRIMARY MINERALOGY	PERCENT PRESENT	PERCENT ORIGINAL	SIZE (mm)	COMPOSITION	MORPHOLOGY	COMMENTS
PHENOCRYSTS						
Olivine	1.2	1.2	0.1-0.5	~Fo85	"Sub- to euhedral, equant"	"Fresh; individual crystals or attached to plagioclase, microphenocrysts of 0.1-0.2 mm diameter most common."
Plagioclase	3.6	3.6	0.3-2		Sub- to euhedral laths	"Oscillatory zoning, sector zoning and glass inclusions (in cores) are common. Present as single crystals or monomineralic glomeroporphyritic clusters. Spinel inclusions (0.1 mm). "
Spinel	Tr	Tr	0.04		Euhedral	
GROUNDMASS						
Plagioclase	17	17	<=0.5		Microlitic laths	Skeletal crystals (swallowtail and hollow forms). 
Olivine	4	4	<=0.1	~Fo85	"Sub- to euhedral, equant"	See comments above.
Mesostasis	69.4	69.4				Subvariolitic groundmass. Contains traces of pyrite in rounded blebs (<=30 micron diameter) and traces of 2 micron magnetite grains.
Glass	3.2	3.2				Fresh quenched margin (1-2mm thick) with varioles. Light to dark brown.
Pyrite	Tr	Tr	<=0.01		Granular	In mesostasis.
SECONDARY MINERALOGY	PERCENT	REPLACING/ FILLING				COMMENTS:
Saponite?	Tr	Fracture				Discontinuous 2 micron wide fracture fill. May correspond to the blue-gray to blue-green clay minerals observed on the surface of the handspecimen.

VESICLES/ CAVITIES	PERCENT	DISTRIBUTION	SIZE (mm)	FILLING	SHAPE	COMMENTS:
Vesicles	1.6	Even	0.1-0.2	None	Spherical to oval.	The bluish mineral observed lining vesicles in the handspecimen is apparently not present in the thin section.

COMMENTS:	Very fresh basalt. Trace plagioclase glomerocrysts (2mm).