Computer Science
Scientific paper
Nov 1970
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1970gecoa..34.1133n&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 34, Issue 11, pp.1133-1159
Computer Science
11
Scientific paper
To distinguish between episodic and continuous-diffusion loss mechanisms, and to compare the response of different parent-daughter systems to metamorphism, we have studied a series of well-exposed plutons, all about 2700 × 10 6 yr old and showing different degrees of metamorphism. The Louis Lake granodiorite pluton in the southern Wind River Range, Wyoming was selected to represent granitic rocks only slightly affected by later disturbances (intrusion of Precambrian diabase dikes and gentle Laramide uparching). Rb-Sr data on total-rock samples form a linear array on the Sr-evolution diagram, indicating that the pluton was emplaeed 2630 ± 20 × 10 6 yr ago ( Rb 87 = 1.39 × 10 -11 yr -1 ) with an initial Sr 87 / Sr 86 ratio of 0.702 ± 0.001. Data on cogenetic zircon fractions form a linear array on a coupled Pb-U evolution diagram with a primary intercept of 2687 ± 15 × 10 6 yr. The secondary intercept of 130 ±100 × 10 6 yr is distinctly lower than the 480 to 660 × 10 6 yr intercepts predicted by single-phase continuous-diffusion models. If the zircons reflect Laramide disturbance, this is not detected by the Rb-Sr data on mineral separates. Disturbance of these data is readily apparent only in rocks with high Rb / Sr ratios and has yielded no apparent secondary ages younger than 2000 × 10 6 yr.
Naylor R. S.
Steiger Rudolf H.
Wasserburg Gerald J.
No associations
LandOfFree
U---Th---Pb and Rb---Sr systematics in 2700 × 10 6 -year old plutons from the southern Wind River Range, Wyoming does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with U---Th---Pb and Rb---Sr systematics in 2700 × 10 6 -year old plutons from the southern Wind River Range, Wyoming, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and U---Th---Pb and Rb---Sr systematics in 2700 × 10 6 -year old plutons from the southern Wind River Range, Wyoming will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1012173