Sample COBA 1-92

NavDat sample number 42415 · TONALITE

Sample

Sample ID	COBA 1-92
Rock name	TONALITE
Rock type	PLUTONIC
Composition	INTERMEDIATE
Material	IGNEOUS

Location

Latitude	38.0132
Longitude	-123.403
State / province	California
Location comment	biotite, sphene bearing tonalite at 130 feet depth on northern Cordell Bank

Age

Age (Ma)	Error	Min	Max	Geologic age	Dated by
95		85.5	104.5

Analyses

WHOLE ROCK

Item	Value	Std. dev.	Unit	Method
RB	91		PPM	EDXRF
SR	375		PPM	EDXRF
RB_SR	0.243			MS
RB87_SR86	0.703			MS
SR87_SR86	0.70612			MS
SR87_SR86_INITIAL	0.7051			MS

References

Kistler, R W; Champion, D E (2001) Rb-Sr whole-rock and mineral ages, K-Ar, (super 40) Ar/ (super 39) Ar, and U-Pb mineral ages, and strontium, lead, neodymium, and oxygen isotopic compositions for granitic rocks from the Salinian Composite Terrane, California. Open-File Report - U. S. Geological Survey. 2001.