Sample BC-16

NavDat sample number 31250 · RHYOLITE

Sample

Sample ID	BC-16
Rock name	RHYOLITE
Rock type	VOLCANIC
Composition	FELSIC
Material	IGNEOUS
Comment	Nearly hylopolitic (obsidian-like), clinopyroxene-bearing rhyolite. A very small proportion of the rock consists of plagioclase and lesser amounts of Fe-rich aguite, hornblende and Fe-Ti oxide microphenocrysts. A few plagioclase grains a ophitic, enclasing smaller clinopyroxenes. The groundmass is vitrophyric and consists of colorless glasss showing flow-like texture.

Age (Ma)	Error	Min	Max	Geologic age	Dated by
45.6		37.4	53.8

Item	Value	Unit	Method
SIO2	74.45	WT%	XRF
TIO2	0.12	WT%	XRF
AL2O3	12.75	WT%	SRC AND AAS
FEO	2.19	WT%	XRF
MNO	0.06	WT%	XRF
MGO	0.06	WT%	SRC AND AAS
CAO	1.38	WT%	XRF
NA2O	4.37	WT%	SRC AND AAS
K2O	3.38	WT%	XRF
P2O5	0.01	WT%	XRF
TOTAL	98.77	WT%	XRF
RB	141	PPM	XRF
SR	79	PPM	XRF
Y	59	PPM	XRF
ZR	277	PPM	XRF
BA	1005	PPM	XRF
V	12	PPM	XRF
CR	135	PPM	XRF
NI	8	PPM	XRF
SR87_SR86	0.706396		ICPMS