Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published 1980 | public
Book Section - Chapter

Early Archean Sm-Nd model ages from a tonalitic gneiss, northern Michigan

Abstract

Sm-Nd model ages on a whole-rock sample of the gneiss at Watersmeet, Michigan, show that these rocks were added to the continental crust about 3,600 m.y. ago. These model ages are calculated by assuming that the rocks were derived from a mantle reservoir with the Sm/Nd ratio of CHUR, which corresponds approximately to the chondritic ratio. These data confirm the U-ThPb zircon results that indicated a minimum age of 3,410 m.y. and possibly an age as old as 3,800 m.y. This study further illustrates the utility of Sm-Nd model ages in deciphering the history of complex Precambrian terranes.

Additional Information

© 1980 Geological Society of America. Manuscript received by the Society April 25 1979; Revised manuscript received November 26, 1979; Manuscript accepted January 11, 1980. We thank R. Zartman, Z. Peterman, and P. Sims for the sample of the gneiss at Watersmeet from northern Michigan. Their endeavors provided the impetus for this study. This study was supported by National Science Foundation Grant PHY 76-02724 and NGL 05-002-188. Division Contribution No. 3175 (283).

Additional details

Created:
August 19, 2023
Modified:
January 13, 2024