We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Diversity in early crustal evolution: 4100 Ma zircons in the Cathaysia Block of southern China.
- Authors
Guang-Fu Xing; Xiao-Lei Wang; Yusheng Wan; Zhi-Hong Chen; Yang Jiang; Kitajima, Kouki; Ushikubo, Takayuki; Gopon, Phillip
- Abstract
Zircons are crucial to understanding the first 500 Myr of crustal evolution of Earth. Very few zircons of this age (>4050 Ma) have been found other than from a ∼300 km diameter domain of the Yilgarn Craton, Western Australia. Here we report SIMS U-Pb and O isotope ratios and trace element analyses for two ,4100 Ma detrital zircons from a Paleozoic quartzite at the Longquan area of the Cathaysia Block. One zircon (207Pb/206Pb age of 4127 6 4 Ma) shows normal oscillatory zonation and constant oxygen isotope ratios (δ18O = 5.8 to 6.0%). The other zircon grain has a ∼4100 Ma magmatic core surrounded by a ,4070 Ma metamorphic mantle. The magmatic core has elevated δ18O (7.2 ± 0.2%), high titanium concentration (53±3.4 ppm) and a positive cerium anomaly, yielding anomalously high calculated oxygen fugacity (FMQ + 5) and a high crystallization temperature (910°C). These results are unique among Hadean zircons and suggest a granitoid source generated from dry remelting of partly oxidizing supracrustal sediments altered by surface waters. The ∼4100 Ma dry melting and subsequent ∼4070 Ma metamorphism provide new evidence for the diversity of the Earth's earliest crust.
- Subjects
CHINA; ZIRCON; SILICATE minerals; TRACE elements; TITANIUM group
- Publication
Scientific Reports, 2014, p1
- ISSN
2045-2322
- Publication type
Article
- DOI
10.1038/srep05143