Sample E-2N

NavDat sample number 5518 · RHYODACITE

Sample

Sample ID	E-2N
Rock name	RHYODACITE
Rock type	VOLCANIC
Composition	FELSIC
Material	IGNEOUS
Comment	Dark-reddish-brown to gray, locally flow-banded porphyritic rock composed of 15-18 percent plagioclase An52-55 and 8-10 percent biotite phenocrysts in a pilotaxitic to hyalopilitic groundmass composed of about 10 percent plagioclase An45-50, 5 percent biotite, 50-55 percent glass, rare pyroxene, 1-2 percent hematite-magnetite. Accessory minerals are apatite and zircon. Vesicles comprise about 4 percent of the sample and are filled with unidentified isotropic and low-birefringent minerals.

Age (Ma)	Error	Min	Max	Geologic age	Dated by
25.9		24.9	26.9

Item	Value	Unit	Method
SIO2	66.6	WT%	RAPID_ROCK
AL2O3	16	WT%	RAPID_ROCK
FE2O3	3.7	WT%	RAPID_ROCK
FEO	0.06	WT%	RAPID_ROCK
MGO	1.2	WT%	RAPID_ROCK
CAO	3.2	WT%	RAPID_ROCK
NA2O	4.1	WT%	RAPID_ROCK
K2O	4.1	WT%	RAPID_ROCK
H2O_PLUS	0.59	WT%	RAPID_ROCK
H2O_MINUS	0.46	WT%	RAPID_ROCK
TIO2	0.48	WT%	RAPID_ROCK
P2O5	0.32	WT%	RAPID_ROCK
MNO	0.06	WT%	RAPID_ROCK
CO2	0.05	WT%	RAPID_ROCK
CL	0.016	WT%	RAPID_ROCK
F	0.036	WT%	RAPID_ROCK
S	0.041	WT%	RAPID_ROCK
MN	600	PPM	SPEC
BA	1800	PPM	SPEC
CO	12	PPM	SPEC
CR	22	PPM	SPEC
CU	49	PPM	SPEC
LA	82	PPM	SPEC
NI	18	PPM	SPEC
PB	25	PPM	SPEC
SC	7	PPM	SPEC
SR	510	PPM	SPEC
V	60	PPM	SPEC
Y	18	PPM	SPEC
ZN	140	PPM	SPEC
ZR	230	PPM	SPEC
GA	27	PPM	SPEC
YB	3	PPM	SPEC