Abstract
The northeastern portion of the Idaho batholith (NIB) intruded Proterozoic rocks of the Belt-Purcell supergroup between 50 and 90 Ma. Premagmatic zircons from one sample of the NIB were analyzed individually using the SHRIMP ion microprobe and yielded a single age population at 1.74 Ga. This apparently single-aged source contrasts with the range of ages reported for zircons from sedimentary rocks of the Belt-Purcell supergroup and suggests that the batholith was not the product of melting Belt-Purcell sediments, nor was it significantly contaminated with these sediments. The source of the batholith, however, appears to be of appropriate age and composition to be a major contributor of sediment to the Belt basin. The source of at least part of the batholith was extracted largely from 1.74 Ga depleted mantle, with little or no input from older rocks. -from Authors
Original language | English (US) |
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Pages (from-to) | 63-72 |
Number of pages | 10 |
Journal | Journal of Geology |
Volume | 103 |
Issue number | 1 |
DOIs | |
State | Published - 1995 |
Externally published | Yes |
ASJC Scopus subject areas
- Geology