Lithospheric thermal structure and rheology of the eastern China

被引:40
作者
Wang, Yang [1 ]
Cheng, Su-Hua [1 ]
机构
[1] China Univ Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China
基金
中国国家自然科学基金;
关键词
Geotherm; Rheological strength; Continental lithosphere; Eastern China; SEISMIC VELOCITY STRUCTURE; HEAT-FLOW DATA; CONTINENTAL-CRUST; MANTLE TEMPERATURES; ELASTIC THICKNESS; MAINLAND CHINA; EVOLUTION; BENEATH; CRATON; EXTENSION;
D O I
10.1016/j.jseaes.2011.11.022
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Temperature distributions of the lithosphere beneath the eastern China were estimated by local isostasy equilibrium constrained geothermal calculation in this study. Maps of the lateral temperature variation at depths of 50 and 100 km as well as Moho boundary are presented for the eastern China continent, and the 600 degrees C and 1100 degrees C isotherm depth maps are also given. Meanwhile, the thermal thickness of lithosphere is calculated as the depth of 1350 degrees C isotherm. The rheological strength of lithosphere is calculated based on a four-layer model, which consists of the upper, lower, lowermost crust layers and a wet lithospheric mantle layer. The results show that, the lithosphere of 160-180 km thick exists under Sichuan basin in the western part of Yangtze Craton, but keel is absent beneath the entire North China Craton. It is notable that the lithospheric thickness is only 130-140 km beneath Ordos basin in the western part of North China Craton; accordingly, there is no lithospheric keel beneath Ordos basin. These geothermal modeling results are in good agreement with those of seismic tomography and other geothermal studies. The temperatures in the lower crust of the North China Craton estimated are in range of 500-600 degrees C. Consequently, the composition of lower crust of the North China Craton should be more mafic than that of previous estimation based on much cooler geotherms. The spatial variation of lit lospheric rheology in the eastern China is influenced by local geotherms and crustal compositions. The "creme brulee" model, which is represent by a strong crust portion but a weak lithospheric mantle portion in vertical strength profile, approximates the lithospheric theological layering for the regions of the western half of North China Craton and the northern part of NE China, which has thicker crust or moderate-to-high geotherm. On the other hand, the "jelly sandwich" model demonstrates the rheological layering of the western part of the Yangtze Craton and the eastern half of the North China Craton. which has how-to-moderate geotherm and/or thinner crust. In general, thermal age of the tectonic province controls the present-day thermal structure and rheology of the lithosphere of the eastern China. (C) 2011 Elsevier Ltd. All rights reserved.
引用
收藏
页码:51 / 63
页数:13
相关论文
共 112 条
  • [11] Burchfiel B.C., 2008, Sichuan, People's Republic of China GSA Today, V18, P4, DOI DOI 10.1130/GSATG18A.1
  • [12] The equivalent elastic thickness (Te), seismicity and the long-term rheology of continental lithosphere: Time to burn-out "creme brulee"? Insights from large-scale geodynamic modeling[J]. Burov, E. B. TECTONOPHYSICS, 2010(1-4)
  • [13] Burov E.B., 2006, GSA Today, V16, DOI [DOI 10.1130/1052-5173(2006)016, DOI 10.1130/1052-5173(2006)016<4:TLTS0C>2.0.C0
  • [14] 2, 10.1130/1052-5173(2006)0162.0.CO
  • [15] 2]
  • [16] FRICTION OF ROCKS[J]. BYERLEE, J. PURE AND APPLIED GEOPHYSICS, 1978(4-5)
  • [17] Inferring upper-mantle temperatures from seismic velocities[J]. Cammarano, F;Goes, S;Vacher, P;Giardini, D. PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 2003(3-4)
  • [18] FLOW PROPERTIES OF CONTINENTAL LITHOSPHERE[J]. CARTER, NL;TSENN, MC. TECTONOPHYSICS, 1987(1-2)
  • [19] Chapman D.S., 1992, CONTINENTAL LOWER CR, V23, P179
  • [20] Chen Moxiang, 1996, PUBLICATION INT LITH, P102