TY - JOUR
T1 - Permian flood basalts from the Tarim Basin, Northwest China: SHRIMP zircon U-Pb dating and geochemical characteristics
AU - Yu, X.
AU - Yang, S.F.
AU - Chen, H.L.
AU - Chen, Zhong
AU - Li, Z.L.
AU - Batt, Geoffrey
AU - Li, Y.Q.
PY - 2011
Y1 - 2011
N2 - This study documents the Permian basalts from the Tarim large igneous province, northwest China. Detailed field work has led to recognition of eight basalt units (BU) in the Permian sequences exposed in the Keping area, northern Tarim Basin. These basalt units are interbedded with terrestrial clastics, and thus represent eight discrete eruptive episodes. The basalt sequence is divided into two major eruption cycles, with an earlier cycle comprising two BUs within the uppermost Kupukuziman Formation, separated by similar to 1000 m of clastic sediments from an upper eruptive cycle represented by a further six BUs in the upper part of the Kaipaizileike Formation. SHRIMP U-Pb zircon ages of 289.5 +/- 2.0 Ma (MSWD =2.2) for the lowermost BU1 and 288 +/- 2.0 Ma (MSWD = 3.1) for the uppermost BU8 are statistically indistinguishable, and limit the duration of the entire eruptive phase to no more than 5.5 Ma. The Keping basalts exhibit OIB-like trace element patterns, enrichment of LILE and HFSE, high (Sr-87/Sr-86)(i) ratios and negative epsilon Nd(t) values - all of which are consistent with the mantle plume derivation. The parental magmas for these basalts were extracted from spinet to garnet lherzolite by low-degree (less than 8%) partial melting. The magmas underwent pre-eruption fractional crystallization, but did not experience significant crustal contamination. (C) 2010 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
AB - This study documents the Permian basalts from the Tarim large igneous province, northwest China. Detailed field work has led to recognition of eight basalt units (BU) in the Permian sequences exposed in the Keping area, northern Tarim Basin. These basalt units are interbedded with terrestrial clastics, and thus represent eight discrete eruptive episodes. The basalt sequence is divided into two major eruption cycles, with an earlier cycle comprising two BUs within the uppermost Kupukuziman Formation, separated by similar to 1000 m of clastic sediments from an upper eruptive cycle represented by a further six BUs in the upper part of the Kaipaizileike Formation. SHRIMP U-Pb zircon ages of 289.5 +/- 2.0 Ma (MSWD =2.2) for the lowermost BU1 and 288 +/- 2.0 Ma (MSWD = 3.1) for the uppermost BU8 are statistically indistinguishable, and limit the duration of the entire eruptive phase to no more than 5.5 Ma. The Keping basalts exhibit OIB-like trace element patterns, enrichment of LILE and HFSE, high (Sr-87/Sr-86)(i) ratios and negative epsilon Nd(t) values - all of which are consistent with the mantle plume derivation. The parental magmas for these basalts were extracted from spinet to garnet lherzolite by low-degree (less than 8%) partial melting. The magmas underwent pre-eruption fractional crystallization, but did not experience significant crustal contamination. (C) 2010 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
U2 - 10.1016/j.gr.2010.11.009
DO - 10.1016/j.gr.2010.11.009
M3 - Article
SN - 1342-937X
VL - 20
SP - 485
EP - 497
JO - Gondwana Research
JF - Gondwana Research
ER -