thumbnail

A tale of 10 plutons - Revisited: Age of granitic rocks in the White Mountains, California and Nevada

Geological Society of America Bulletin

By:
,

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time

Abstract

40Ar/39Ar incremental heating analysis and conventional K-Ar age determinations on plutonic rocks of the White Mountains define two stages of magmatic emplacement: Late Cretaceous, between ca. 90 Ma and 75 Ma, and Middle-Late Jurassic, between ca. 180 and 140 Ma. The Jurassic stage can be divided into two substages, 180-165 Ma and 150-140 Ma. Thermal effects of the younger plutons on the older granitoids partially to completely reset ages, making it difficult to determine the age of emplacement and cooling of several of the plutons even by 40Ar/39Ar incremental heating analyses. New data together with published ages and regional geochronological synthesis of the Sierra Nevada batholith indicate that regions within the batholith have coherent periods or episodes of magmatic activity. In the White Mountains and Sierra Nevada directly to the west there was little or no activity in Early Jurassic and Early Cretaceous time; magmatism took place during relatively short intervals of 15 m.y. or less in the Middle and Late Jurassic and Late Cretaceous periods. The new K-Ar and 40Ar/39Ar analyses of granitoids from the White Mountains help, but do not completely clarify the complex history of emplacement, cooling, and reheating of the batholith.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A tale of 10 plutons - Revisited: Age of granitic rocks in the White Mountains, California and Nevada
Series title:
Geological Society of America Bulletin
Volume
108
Issue:
12
Year Published:
1996
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geological Society of America Bulletin
First page:
1515
Last page:
1527
Number of Pages:
13