THIN SECTION:	"U1301B-1R-1, 14-18 cm (Piece 2)"				TS #	1	Unit:1A	"OBSERVER: MS, RC"
ROCK NAME: 	Basalt-hyaloclastite breccia							
WHERE SAMPLED:	Hyaloclastite							
GRAIN SIZE:	Clay and clasts							
TEXTURE:	Breccia							
PRIMARY	PERCENT 	PERCENT	SIZE (mm)			APPROX.		
MINERALOGY	PRESENT 	ORIGINAL	min.	max.	av.	COMP.	MORPHOLOGY	COMMENTS
PHENOCRYSTS								



GROUNDMASS								
Plagioclase	Tr	Tr		<0.3			Euhedral to subhedral	Microlaths in the fresh and altered glass.
Glass								



SECONDARY			SIZE (mm)					
MINERALOGY	PERCENT		min.	max.	av.		REPLACING / FILLING	COMMENTS
Saponite	10						"Matrix of hyaloclastite, vesicles, and mesostasis"	Brown to brown-gray color.
Zeolites	2							
Carbonate	1							

VESICLES/			SIZE (mm)					
CAVITIES	PERCENT	 LOCATION	min.	max.	av.		FILLING / MORPHOLOGY	COMMENTS
Vesicles	Tr	Even	0.2	0.3	0.25		"Saponite, zeolite, and pyrite."	



COMMENTS : 	"The matrix of the hyaloclastite consists of saponite, zeolite, and carbonate. Pyrite is present in the altered glass."