Sample 13

NavDat sample number 5462

Sample

Sample ID	13
Rock type	VOLCANIC
Material	IGNEOUS

Location

Latitude	23.875
Longitude	-104.65
Location	Durango City
State / province	Durango
Formation	Santa Maria Formation

Age

Age (Ma)	Error	Min	Max	Geologic age	Dated by
28.3		27.7	28.9

Analyses

Whole Rock

Item	Value	Std. dev.	Unit	Method
SIO2	73.79		WT%	UNKNOWN
TIO2	0.33		WT%	UNKNOWN
AL2O3	13.41		WT%	UNKNOWN
FE2O3	2.04		WT%	UNKNOWN
FEO	0.46		WT%	UNKNOWN
MNO	0.06		WT%	UNKNOWN
MGO	0.26		WT%	UNKNOWN
CAO	1.05		WT%	UNKNOWN
NA2O	4.05		WT%	UNKNOWN
K2O	4.2		WT%	UNKNOWN
H2O_PLUS	0.44		WT%	UNKNOWN
H2O_MINUS	0.22		WT%	UNKNOWN
P2O5	0.07		WT%	UNKNOWN
CO2	0.04		WT%	UNKNOWN

References

Swanson, E R; Keizer, R P; Lyons, J I; Clabaugh, S E (1978) Tertiary volcanism and caldera development near Durango City, Sierra Madre Occidental, Mexico. Geological Society of America Bulletin, vol.89, no.7, pp.1000-1012, Jul 1978 doi:10.1130/0016-7606(1978)89<1000:TVACDN>2.0.CO;2