THIN SECTION:	"U1301B-18R-4, 66-67 cm (Piece 2a)"				TS #	34	Unit:6	"OBSERVER: MS, RC"
ROCK NAME: 	Sparsely clinopyroxene-olivine-plagioclase phyric basalt							
WHERE SAMPLED:	Massive flow margin							
GRAIN SIZE:	Crypto to microcrystalline							
TEXTURE:	"Intersertal to intergranular, glomeroporphyritic"							
PRIMARY	PERCENT 	PERCENT	SIZE (mm)			APPROX.		
MINERALOGY	PRESENT 	ORIGINAL	min.	max.	av.	COMP.	MORPHOLOGY	COMMENTS
PHENOCRYSTS								
Plagioclase	3	3	0.7	1.7	1.2		Euhedral to subhedral	"Laths and skeletal crystals, and in mono- and poly-mineralic glomeroporphyritic clots."
Clinopyroxene	1	1	0.5	1.2	0.8		Euhedral to anhedral	"Occurs singly, but more frequently in glomeroporphyritic clots or associated with plagioclase laths."
Olivine	0	1	0.3	1.8	0.8		Euhedral to subhedral	Completely replaced by saponite.


GROUNDMASS								
Plagioclase	63	63		<0.7			Euhedral to subhedral	Laths and needles.
Clinopyroxene	17	17		<0.5			Euhedral to anhedral	Occurs singly or attached to/intergrown with plagioclase.
Olivine	0	5		<0.3			Euhedral to subhedral	Completely replaced by clay.
Mesostasis	3	5						

SECONDARY			SIZE (mm)					
MINERALOGY	PERCENT		min.	max.	av.		REPLACING / FILLING	COMMENTS
Saponite	15						"Olivine, mesostasis"	Brown to brown-gray color.



VESICLES/			SIZE (mm)					
CAVITIES	PERCENT	 LOCATION	min.	max.	av.		FILLING / MORPHOLOGY	COMMENTS
Vesicles	Tr	Even	0.2	0.3	0.25			



COMMENTS : 	"There is a marked change of groundmass grain size, this texture is associated with quenching."