Early Cretaceous uplift history of the Dabie orogenic belt： Evidence from pluton emplacement depths

• Published in: Science China. Earth sciences Vol. 57; no. 5; pp. 1129 - 1140
• Main Authors: Wang, YongSheng, Wang, HaiFeng, Sheng, Yong, Xiang, BiWei
• Format: Journal Article
• Language: English
• Published: Heidelberg Science China Press 01.05.2014; Springer Nature B.V
• Subjects: Cretaceous; Earth and Environmental Science; Earth Sciences; Geochemistry; Geological time; Geophysics; Granite; Igneous rocks; Plate tectonics; Research Paper; 侵位深度; 大别造山带; 岩体侵位; 早白垩世; 碱长花岗岩; 花岗闪长岩; 锆石U-Pb年龄; 隆升历史; Early Cretaceous plutons; Dabie orogenic belt; Al-in-hornblende geobarometer; North Dabie complex belt
• ISSN: 1674-7313; 1869-1897
• DOI: 10.1007/s11430-013-4659-5

The North Dabie complex unit （NDC） is a widely exposed petro-tectonic unit. To understand post-orogenic uplift history and mechanism of the Dabie orogenic belt, many samples of granite, granodiorite, diorite, and alkali feldspar granite with precise zircon U-Pb ages were collected for electron microprobe analysis of hornblende. Emplacement pressure values were then cal- culated by using an Al-in-hornblende geobarometer. The result shows that total A1 （A1T） values in hornblende range from 1.17 to 1.97 p.f.u., XFe（=Fe/（Fe＋Mg）） from 0.4 to 0.65, and corresponding pressure values from 256.8 to 676.2 MPa for A1T greater than 1.17. It is suggested that although the main mechanism for the uplift is tectonic extension, inhomogeneous uplift related to the pluton emplacement is also important during post-orogenic evolution of the Dabie orogenic belt. Emplacement depth dis- tribution of the plutons shows that uplift in the NDC is affected by horst-graben structures since 120 Ma.