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SAMPLE INFO : Snyder_1959_12

Sample ID:	Snyder_1959_12
Station ID:	Snyder_1959_12
Latitude:	51.9531
Longitude:	178.5356
Datum:	NAD83
Sample Type 1:	Lava
Field Lithology:	Dacite

Text Description:
Rhyodacite of Pratt Point member of Little Sitkin dacite. Color: yellowish gray (5 P 7/1) to medium light gray (N 6). Texture: hypocrystalline, vesicular with "hairy" pumice developed locally, porphyritic with hornblende phenocrysts as much as 7 mm long and feldspar phenocrysts as much as 4 mm long. Plagioclase, 15-20 percent, ranges in composition from An27 to An50 and averages An40; sometimes poikilitic with inclusions of hornblende. Accessory minerals: oxyhornblende, 3-4 percent; hypersthene, 2-3 percent; quartz, 2-3 percent; magnetite, 1 percent. The quartz is characterized by conchoidal fractures and is very susceptible to plucking during grinding. The groundmass is about half small bubbles and half clear pinkish glass (N=1.490). The few plagioclase microlites average An39( ?).

References:

Geology of Little Sitkin Island, Alaska

GEOCHEM DATA

StationID	Latitude	Longitude	Geologist	DateVisited	Age Info	Volcano	Eruption	Location Description	Text Description	Sample ID	Sample Type 1	Sample Type 2	Final Unit	Material	SiO2	TiO2	Al2O3	FeOT	MnO	MgO	CaO	Na2O	K2O	P2O5	Total-majors	REF majors	METH majors	Fe2O3/Fe203T orig	FeO/FeOT orig	Volatiles csv	METH volatiles	Cs	Rb	Ba	Sr	La	Ce	Pr	Nd	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu	Y	Zr	Nb	Hf	Ta	Pb	Th	U	Sc	V	Cr	Fe	Co	Ni	Cu	Zn	Ga	Mo	As	Na	K	Ref trace1	METH trace1	Rb	Ba	Sr	La	Ce	Nd	Sm	Eu	Gd	Dy	Er	Yb	Lu	Y	Zr	Nb	Pb	Th	U	Sc	Ti	V	Cr	Ni	Cu	Zn	Ga	Ref trace2	METH trace2	Light csv	Halogen csv	other major csv	other lile csv	other ree csv	other hfse csv	other hpe csv	other tm csv	other misc csv
Snyder_1959_12	51.9531	178.5356	Snyder, G. L.			Little Sitkin		Pratt Point member of Little Sitkin dacite from central part of mapped area about 0.9 mile south of East Point	Rhyodacite of Pratt Point member of Little Sitkin dacite. Color: yellowish gray (5 P 7/1) to medium light gray (N 6). Texture: hypocrystalline, vesicular with "hairy" pumice developed locally, porphyritic with hornblende phenocrysts as much as 7 mm long and feldspar phenocrysts as much as 4 mm long. Plagioclase, 15-20 percent, ranges in composition from An27 to An50 and averages An40; sometimes poikilitic with inclusions of hornblende. Accessory minerals: oxyhornblende, 3-4 percent; hypersthene, 2-3 percent; quartz, 2-3 percent; magnetite, 1 percent. The quartz is characterized by conchoidal fractures and is very susceptible to plucking during grinding. The groundmass is about half small bubbles and half clear pinkish glass (N=1.490). The few plagioclase microlites average An39( ?).	Snyder_1959_12	Lava			Whole-rock	68.99	0.38	15	3.65	0.12	1.15	3.45	4.3	2.06	0.11	99.86	424	NN	1.52	2.27	H2OM=0.08; H2OP=0.64; CO2=0.01	NN		45.1		245																												5.9							units are percent 1.7	745	XRF: Rb, Sr, Ni; NN: K;

SAMPLE LOCATION

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