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SAMPLE INFO : SG05-16

Sample ID:	SG05-16
Station ID:	SG05-16
Latitude:	56.590118409241
Longitude:	-169.4741244334
Datum:	NAD83
Sample Type 1:	Lava

Text Description:
St. George Island, Group 1 type rocks (from Chang and others, 2009): "Group 1 rocks are commonly crystal poor (5-15 vol. % phenocrysts) and vesicular, with fine-grained, holocrystalline groundmasses. Phenocrysts are primarily olivine, although some rocks have clinopyroxene or opaque phenocrysts as well. The olivine phenocrysts are commonly equant or skeletal and vary widely in size and form from sample to sample and within rocks. Olivine compositions for seven rocks range from Fo90 to Fo61 and average Fo83. Clinopyroxene phenocrysts are generally small and euhedral and have average core and rim compositions of XMg=70 and 62, respectively. Clinopyroxene phenocrysts vary in color from tan to pink in plane-polarized light and often exhibit sector-zoning and occur in X- or star-shaped glomerocrystic clusters. The groundmasses generally consist of olivine, euhedral clinopyroxene, euhedral plagioclase laths, and opaque minerals. Modal nepheline was found in one rock (SG06-8). Abundant groundmass clinopyroxene is especially notable in group 1 rocks. The average clinopyroxene in the groundmass has a composition of XMg=66. Plagioclase compositions measured in two group 1 rocks are variable. The average plagioclase composition in sample SG05-28 is Ab36Or3An61, with two analyzed crystals having anomalous rims with an average composition of Ab48Or37An15. Plagioclase analyzed in sample SG05-31 is albite (Ab84Or12An3)."

References:

Petrogenesis of basaltic volcanic rocks from the Pribilof Islands, Alaska, by melting of metasomatically enriched depleted lithosphere, crystallization differentiation, and magma mixing

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
SG05-16	56.590118409241	-169.4741244334	Unknown, Unknown	0000-00-00		St. George volcanic field		Group 1	St. George Island, Group 1 type rocks (from Chang and others, 2009): "Group 1 rocks are commonly crystal poor (5-15 vol. % phenocrysts) and vesicular, with fine-grained, holocrystalline groundmasses. Phenocrysts are primarily olivine, although some rocks have clinopyroxene or opaque phenocrysts as well. The olivine phenocrysts are commonly equant or skeletal and vary widely in size and form from sample to sample and within rocks. Olivine compositions for seven rocks range from Fo90 to Fo61 and average Fo83. Clinopyroxene phenocrysts are generally small and euhedral and have average core and rim compositions of XMg=70 and 62, respectively. Clinopyroxene phenocrysts vary in color from tan to pink in plane-polarized light and often exhibit sector-zoning and occur in X- or star-shaped glomerocrystic clusters. The groundmasses generally consist of olivine, euhedral clinopyroxene, euhedral plagioclase laths, and opaque minerals. Modal nepheline was found in one rock (SG06-8). Abundant groundmass clinopyroxene is especially notable in group 1 rocks. The average clinopyroxene in the groundmass has a composition of XMg=66. Plagioclase compositions measured in two group 1 rocks are variable. The average plagioclase composition in sample SG05-28 is Ab36Or3An61, with two analyzed crystals having anomalous rims with an average composition of Ab48Or37An15. Plagioclase analyzed in sample SG05-31 is albite (Ab84Or12An3)."	SG05-16	Lava			Whole-rock	43.61511	2.87765	13.52063	11.92924	0.18607	11.86514	10.29976	3.35884	1.80376	0.62341	99.33256	4882	XRF		11.92924				22.6	282.5	649.9	31.2	64.5													25	215.7	55.2			2.4	4.8		24.6	267.2	295.6			245.9		103						4882	XRF

SAMPLE LOCATION

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