National Geochronological Database sample #14342

Outcrop or artificial surface exposure, Gneiss

Geographic location
-165.3, 64.966667
165° 18' " W, 64° 58' " N
AK
Nome D-1 1:63,360 scale map quadrangle
Accurate to within 5 minute (~5 miles)
KIGLUAIK MOUNTAINS, SEWARD PENINSULA
Source of sample Outcrop or artificial surface exposure
Rock name Gneiss
Description PARAGNEISS, KIGLUAIK GROUP
Laboratories USGS Denver
Compiler name Degourville, A.E.
Date compiled 1984 04
Precision of location Accurate to within 5 minute (~5 miles)
Location comment KIGLUAIK MOUNTAINS, SEWARD PENINSULA
Bibliographic reference Bunker, C.M., Hedge, C.E., and Sainsbury, C.L., 1979, Radioelement Concentrations and Preliminary Radiometric Ages Of Rocks Of The Kigluaik Mountains, Seward Peninsula, Alaska: U.S. Geological Survey Professional Paper 1129-C, C12p.
(click for info)
Geologic map unit -165.3, 64.966667
Nearby scientific data Find additional scientific data near this location

Rb-Sr age determinations

Age estimate 732Ma
Type of analysis Conventional Rb-Sr (assumed initial 87Sr/86Sr)
Rock or mineral analyzed whole rock
Analytical details
Lab sample ID 70ACH-16
Decay constants 1.42E-05
Rubidium concentration 101 ppm
Strontium concentration 199 ppm
Initial 87Sr/86Sr 0.7043
Ratio 87Rb/86Sr 1.467
Ratio 87Sr/86Sr 0.7193
Normal? T
Age estimate 735Ma
age of metamorphic crystallization
Type of analysis 87Sr/86Sr-87Rb/86Sr isochron (whole rock)
5-POINT WHOLE-ROCK ISOCHRON
Rock or mineral analyzed whole rock
Analytical details
Lab sample ID 70ACH-16
Sample suite # 590
Decay constants 1.42E-05
Rubidium concentration 101 ppm
Strontium concentration 199 ppm
Initial 87Sr/86Sr 0.7043
Ratio 87Rb/86Sr 1.467
Ratio 87Sr/86Sr 0.7193
Normal? T