Sample 73

NavDat sample number 88038 · RHYODACITE

Sample

Sample ID	73
Rock name	RHYODACITE
Rock type	VOLCANIC
Composition	FELSIC
Material	IGNEOUS
Collected by	Hildreth and others
Comment	Largest intracaldera dome, multilobate

Location

Latitude	48.8375
Longitude	-121.704
Location	Ptarmigan Dome
State / province	Washington

Age

Age (Ma)	Error	Min	Max	Geologic age	Dated by
1.013		1.005	1.021

Analyses

Whole rock

Item	Value	Std. dev.	Unit	Method
SIO2	71.2		WT%	XRF
TIO2	0.4		WT%	XRF
AL2O3	15.1		WT%	XRF
FEOT	2.29		WT%	XRF
MNO	0.04		WT%	XRF
MGO	0.6		WT%	XRF
CAO	1.81		WT%	XRF
NA2O	4.82		WT%	XRF
K2O	3.16		WT%	XRF
P2O5	0.13		WT%	XRF
LOI	0.96		WT%	XRF
TOTAL	98.28		WT%	XRF
RB	67		PPM	XRF
SR	255		PPM	XRF
Y	29		PPM	XRF
ZR	235		PPM	XRF
BA	970		PPM	XRF
CE	58		PPM	XRF
V	40		PPM	XRF

References

Hildreth, Wes; Lanphere, Marvin A; Champion, Duane E; Fierstein, Judy (2004) Rhyodacites of Kulshan Caldera, north Cascades of Washington;post-caldera lavas that span the Jaramillo. Journal of Volcanology and Geothermal Research, vol.130, no.3-4,pp.227-264, 29 Feb 2004 doi:10.1016/S0377-0273(03)00290-7