4.7 Article

Creation of a continent recorded in zircon zoning

期刊

GEOLOGY
卷 36, 期 3, 页码 239-242

出版社

GEOLOGICAL SOC AMER, INC
DOI: 10.1130/G24416A.1

关键词

zircon; U-Pb; oxygen isotopes; ion probe; lower crust; Kapuskasing; Archean

类别

向作者/读者索取更多资源

We have discovered a robust microcrystalline record of the early genesis of North American lithosphere preserved in the U-Pb age and oxygen isotope zoning of zircons from a lower crustal paragneiss in the Neoarchean Superior province. Detrital igneous zircon cores with delta O-18 values of 5.1%-7.1%c record creation of primitive to increasingly evolved crust from 2.85 +/- 0.02 Ga to 2.67 +/- 0.02 Ga. Sharp chemical unconformity between cores and higher 8110 (8.4%-10.4%) metamorphic overgrowths as old as 2.66 +/- 0.01 Ga dictates a rapid sequence of arc unroofing, burial of detrital zircons in hydrosphere-altered sediment, and transport to lower crust late in upper plate assembly. The period to 2.58 +/- 0.01 Ga included similar to 80 m.y. of high-temperature (similar to 700-650 degrees C, nearly continuous overgrowth events reflecting stages in maturation of the subjacent mantle root. Huronian continental rifting is recorded by the youngest zircon tip growth at 2512 +/- 8 Ma (similar to 600 degrees C) signaling magma intraplating and the onset of rigid plate behavior. This >150 m.y. microscopic isotope record in single crystals demonstrates the sluggish volume diffusion of U, Pb, and O in zircon throughout protracted regional metamorphism, and the consequent advances now possible in reconstructing planetary dynamics with zircon zoning.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据