Dynamic Magma Systems, Crustal Recycling, and Alteration in the Central Sierra Nevada Batholith: the Oxygen Isotope Record 论文

详细信息

发表期刊/会议

Journal of Petrology

发表日期

2008-06-19

发表年份

2008

摘要

Values of 18O of zircon from the central Sierra Nevada batholith (SNB), California, yield fresh insight into the magmatic evolution and alteration history of this classic convergent margin batholith. Direct comparison of whole-rock and zircon (Zrc) 18O provides evidence for modest (0.5ø), but widespread, alteration, which has complicated interpretation in previous whole-rock 18O studies. Four discrete belts of 18O values are recognized in the central Sierra. A small belt of plutons with relatively low 18O(Zrc) values (52^60ø) intrudes the foothills, with a sharp increase of 18O revealing the concealed Foothills Suture; high 18O(Zrc) values (70^85ø) dominate the rest of the western SNB. East of the axis of the Sierra, 18O is distinctly lower (675^575ø), and decreases monotonically to the Sierra Crest. A sharp 1ø increase of 18O in the eastern Sierra reveals a second crustal boundary, with the fourth belt hosted in high-18ONorth American crust in the White