Match!

Petrogenesis and tectonic implications of the Triassic volcanic rocks in the northern Yidun Terrane, Eastern Tibet

Published on Aug 1, 2013in Lithos3.91
· DOI :10.1016/j.lithos.2013.05.013
Bai-Qiu Wang4
Estimated H-index: 4
(HKU: University of Hong Kong),
Mei-Fu Zhou71
Estimated H-index: 71
(HKU: University of Hong Kong)
+ 2 AuthorsDan-Ping Yan22
Estimated H-index: 22
(China University of Geosciences)
Abstract
Abstract Triassic Paleo-Tethyan subduction-related volcanic rocks are extensively distributed in the Xiangcheng and Changtai regions, northern Yidun Terrane, eastern Tibet. The ~ 228 Ma volcanic rocks in the Xiangcheng region have intermediate-felsic composition (60.1 to 64.7 wt.% SiO 2 ) with relatively low Y (14–18 ppm) and high Sr (630–1830 ppm) yielding high Sr/Y ratios (43–94). They have LREE-enriched and HREE-depleted REE patterns (La/Yb = 19–26), typical of adakites. Sr–Nd isotopic compositions of these volcanic rocks are similar to those of the contemporaneous high silica adakitic rocks in the southern Yidun Terrane. The ~ 231–230 Ma volcanic rocks in the Changtai region are composed of basalts, andesites, dacites and rhyolites with SiO 2 ranging from 47.7 to 81.0 wt.%. Basalts in the Changtai region have initial 87 Sr/ 86 Sr ratios from 0.7052 to 0.7058 and e Nd (t) from + 1.1 to + 1.5. They display OIB-like geochemical signatures, and were likely derived from low degrees of partial melting of an OIB-like mantle source with subordinate input of subduction components indicated by increasing Th content. Andesites and dacites show elemental and isotopic compositions that evolved from the basalts, indicative of derivation via crustal contamination and fractional crystallization (AFC) of basaltic magmas. Rhyolites have lower initial 87 Sr/ 86 Sr ratios and higher e Nd (t) values than andesites/dacites, inconsistent with an AFC process and, are suggested to have been derived from anatexis of crustal materials. Emplacement of volcanic rocks in the Changtai and Xiangcheng regions could be attributed to the subduction of the Ganzi–Litang Ocean, a branch of the Paleo-Tethys Ocean. Volcanic rocks in the Changtai and Xiangchang regions have zircon U–Pb ages about 4–6 myr older than that of arc granites in the eastern Yidun Terrane. The spatio-temporal distribution of the volcanic rocks indicates that the subduction was initiated under the southern Yidun Terrane in the Middle Triassic and extended to the northern Yidun Terrane at the beginning of the Late Triassic.
  • References (104)
  • Citations (32)
References104
Newest
#1Bai-Qiu Wang (HKU: University of Hong Kong)H-Index: 4
#2Wei Wang (HKU: University of Hong Kong)H-Index: 42
Last.Mei-Fu Zhou (HKU: University of Hong Kong)H-Index: 71
view all 3 authors...
#1Charles H. Langmuir (Harvard University)H-Index: 66
#2Antoine Bezos (Harvard University)H-Index: 11
Last.Stephen W. Parman (Harvard University)H-Index: 22
view all 4 authors...
#1Robert J. Stern (UTD: University of Texas at Dallas)H-Index: 71
#2Matthew J. Fouch (CIS: Carnegie Institution for Science)H-Index: 13
Last.Simon L. Klemperer (Stanford University)H-Index: 53
view all 3 authors...
#1Jian-Wei Zi (CAS: Chinese Academy of Sciences)H-Index: 13
#2Peter A. Cawood (St And: University of St Andrews)H-Index: 70
Last.Eric Tohver (UWA: University of Western Australia)H-Index: 28
view all 5 authors...
Cited By32
Newest
#1Yan-Jun Li (China University of Geosciences)
#2Junhao Wei (China University of Geosciences)H-Index: 9
Last.Ben Liu (China University of Geosciences)
view all 7 authors...
#1Yanjun Li (China University of Geosciences)H-Index: 6
#2Junhao Wei (China University of Geosciences)H-Index: 9
Last.Kun-Jia Ke (China University of Geosciences)H-Index: 1
view all 6 authors...
#1Yan Liu (China University of Geosciences)H-Index: 5
#2Jun Tan (China University of Geosciences)H-Index: 8
Last.Zhi-Hua Wang (China University of Geosciences)
view all 7 authors...
#1Yin Liu (CAS: Chinese Academy of Sciences)H-Index: 1
#2Wenjiao Xiao (CAS: Chinese Academy of Sciences)H-Index: 60
view all 11 authors...
#1Yu Zhu (Northwest University (United States))H-Index: 1
#2Shaocong Lai (Northwest University (United States))H-Index: 20
Last.Fangyi Zhang (Northwest University (United States))H-Index: 1
view all 5 authors...
View next paperMesozoic plutons of the Yidun Arc, SW China: U/Pb geochronology and Hf isotopic signature