Sample HG-40

NavDat sample number 31298 · ANDESITE

Sample

Sample ID	HG-40
Rock name	ANDESITE
Rock type	VOLCANIC
Composition	INTERMEDIATE
Material	IGNEOUS
Comment	Porphyritic andesite with microphenocryst os plagioclase, augite, hyperstene, and rare Fe-Ti oxide. Xenocrysts are abundant and include quartz (up to 5mm long), plagioclase (large, blocky, spongy, up to 4 mm wide and 5 mm long, and showing variable degrees of resoption, as well as variably wide, clear overgrowth rims), and rare orthopyroxene. Large brown glass inclusions are present in both quartz and plagioclase. The groundmass is pilotaxitic to hyalopilitic and compased of plagioclase, orthpyroxene, clinopyroxene, Fe-Ti oxides, and interstitial glass.

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

Item	Value	Unit	Method
SIO2	60.71	WT%	XRF
TIO2	0.89	WT%	XRF
AL2O3	16.34	WT%	SRC AND AAS
FEO	6.11	WT%	XRF
MNO	0.16	WT%	XRF
MGO	4.17	WT%	SRC AND AAS
CAO	6.5	WT%	XRF
NA2O	3.61	WT%	SRC AND AAS
K2O	1.18	WT%	XRF
P2O5	0.14	WT%	XRF
TOTAL	99.88	WT%	XRF
RB	117	PPM	XRF
SR	286	PPM	XRF
Y	25	PPM	XRF
ZR	141	PPM	XRF
BA	644	PPM	XRF
V	144	PPM	XRF
CR	58	PPM	XRF
NI	24	PPM	XRF
SR87_SR86	0.704366		ICPMS