Sample WP-2

NavDat sample number 4776 · RHYOLITE

Sample

Sample ID	WP-2
Rock name	RHYOLITE
Rock type	VOLCANIC
Composition	FELSIC
Material	IGNEOUS
Comment	generally 98% aphanitic groundmass with tiny disseminated grains of magnetite; groundmass comprised of albite, quartz, and orthoclase along with small amounts of biotite flakes perfectly aligned to flow layering; some albite phenocrysts present; prominent macroscopic flow foliation

Latitude	44.4102
Longitude	-103.691
State / province	South Dakota
Volcanic field	Black Hills Tertiary igneous province

Age (Ma)	Error	Min	Max	Geologic age	Dated by
54		50	58

Item	Value	Unit	Method
SIO2	74.72	WT%	NAA
AL2O3	15.14	WT%	NAA
FE2O3	1.19	WT%	NAA
MGO	0.73	WT%	NAA
CAO	0.5	WT%	NAA
NA2O	3.13	WT%	NAA
K2O	4.22	WT%	NAA
TIO2	0.22	WT%	NAA
MNO	0.04	WT%	NAA
BAO	0.11	WT%	NAA
BA	1027	PPM	NAA
CE	61.8	PPM	NAA
CO	0.7	PPM	NAA
EU	1	PPM	NAA
HF	3.4	PPM	NAA
LA	19.1	PPM	NAA
LU	0.2	PPM	NAA
RB	69.8	PPM	NAA
SC	0.6	PPM	NAA
SM	3.6	PPM	NAA
TH	12.6	PPM	NAA
V	8.3	PPM	NAA
YB	1.3	PPM	NAA