首页|Time-space evolution of an Archean craton: A Hf-isotope window into continent formation

Time-space evolution of an Archean craton: A Hf-isotope window into continent formation

扫码查看
原文链接
  • NSTL
  • Elsevier
The Yilgarn Craton of Western Australia represents one of the largest pieces of Precambrian crust on Earth, and a key repository of information on the Meso-Neoarchean period. Understanding the crustal, tectonic, thermal, and chemical evolution of the craton is critical in placing these events into an accurate geological context, as well as developing holistic tectonic models for the Archean Earth. Here, we present a large U-Pb (420 collated samples) and Hf isotopic (2163 analyses) dataset on zircon, and apply it to constrain the evolution of the craton. These data provide strong evidence for a Hadean-Eoarchean origin for the Yilgarn Craton from mafic crust at ca. 4000 Ma, in a proto-craton consisting of the Narryer and north-central Southern Cross Domain. This ancient cratonic nucleus was subsequently rifted, expanded and reworked by successive crustal growth events at ca. 3700 Ma, ca. 3300 Ma, 3000-2900 Ma, 2825-2800 Ma, and ca. 2730-2620 Ma. The < 3050 Ma crustal growth events correlate broadly with lcnown komatiite events, and patterns of craton evolution, revealed by Hf isotope time-slice mapping, image the periodic brealc-up of the Yilgarn proto-continent and the formation of rift-zones between the older crustal blocks. Crustal growth arid new magmatic pulses were focused into these zones and at craton margins, resulting in continent growth via internal (rift-enabled) expansion, and peripheral (crustal extraction at craton margins) magmatism. Consequently, we interpret these major geodynamic processes to be analogous to plume-lid tectonics, where the majority of tonalite-trondhjemite-granodiorite (TTG) felsic crust, and later granitic crust, was formed by reworking of hydrated mafic rocks and TTGs, respectively, via a combination of infra-crustal and/or drip-tectonic settings. We argue that subduction-like processes formed a minor tectonic component, re-docking the Narryer Terrane to die craton at ca. 2740 Ma. Overall, these processes led to an intra-cratonic a

Continental crustCrustal evolutionGeochronologyPlume tectonicsSubductionYilgarn

Mole, D. R.、Kirkland, C. L.、Fiorentini, M. L.、Barnes, S. J.、Cassidy, K. F.、Isaac, C.、Belousova, E. A.、Hartnady, M.、Thebaud, N.

展开 >

Laurentian Univ, Mineral Explorat Res Ctr, Harquail Sch Earth Sci, Sudbury, ON P3E 2C6, Canada

Curtin Univ, Ctr Explorat Targeting Curtin Node, Sch Earth & Planetary Sci, Kent St, Perth, WA 6102, Australia

Univ Western Australia, ARC, Ctr Excellence Core Crust Fluid Syst CCFS, Ctr Explorat Targeting, Perth, WA 6009, Australia

CSIRO, Mineral Resources, 26 Dick Perry Ave, Kensington, WA 6151, Australia

Macquarie Univ, ARC, Ctr Excellence Core Crust Fluid Syst CCFS, ARC Key Ctr Geochem Evolut & Metallogeny Continen, N Ryde, NSW 2109, Australia

展开 >

2019

10.1016/j.earscirev.2019.04.003

Earth-Science Reviews

Earth-Science Reviews

SCI
ISSN：0012-8252
年,卷(期)：2019.196
  • 50
  • 317