National Geochronological Database sample #16542

Outcrop or artificial surface exposure, Schist

Geographic location
-165.373333, 64.565
165° 22' 24" W, 64° 33' 54" N
Bendeleben 1:250,000 scale map quadrangle
Accurate to within 0.1 minute (~500 feet)
Source of sample Outcrop or artificial surface exposure
Rock name Schist
Description with qtz+chlorite+alb
Laboratories University of British Columbia
Compiler name Moscati, R.
Date compiled 1992 04
Precision of location Accurate to within 0.1 minute (~500 feet)
Bibliographic reference Armstrong, R.L., Harakal, J.E., Forbes, R.B., Evans, B.W., and Thurston, S.P., 1986, Rb-Sr and K-Ar study of metamorphic rocks of the Seward Peninsula and the southern Brooks Range, Alaska: Geological Society of America Memoir 164, p. 185-202.
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Geologic map unit -165.373333, 64.565
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Rb-Sr age determinations

Age estimate (no age estimate specified)
Type of analysis 87Sr/86Sr-87Rb/86Sr isochron (mineral-whole rock)
Rock or mineral analyzed whole rock
Analytical details
Lab sample ID 80-93-1
Decay constants 1.42E-05
Rubidium concentration 42.5 ppm
Strontium concentration 68.7 ppm
Initial 87Sr/86Sr 0.708
Ratio 87Rb/86Sr 1.796
Ratio 87Sr/86Sr 0.7407
Normal? T