| Title | Felsic dyke swarms from central Inner Mongolian: Implications for the Triassic tectonic setting in the southeast Central Asian Orogenic Belt |
| Authors | Tang, Jianzhou Zhang, Zhicheng Ding, Cong Liu, Bo |
| Affiliation | Peking Univ, MOE Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China Peking Univ, Sch Earth & Space Sci, Beijing 100871, Peoples R China China Univ Geosci Beijing, Sch Earth Sci & Resources, Beijing 100083, Peoples R China |
| Keywords | NORTH CHINA CRATON SOLONKER SUTURE ZONE BAINAIMIAO ARC BELT I-TYPE GRANITES U-PB CRUSTAL GROWTH CONTINENTAL-CRUST ADJACENT AREAS VOLCANIC-ROCKS HIGH-PRECISION |
| Issue Date | 1-Dec-2021 |
| Publisher | LITHOS |
| Abstract | This work presents the whole-rock elemental geochemistry and Sr - Nd isotopes and zircon Hf - O isotopes for dikes from Tagaolemiao and Tuilamamiao, the southern margin of the southeast Central Asian Orogenic Belt (SE CAOB), to explore their origin and dynamic setting. Zircon U - Pb dating reveals that the Tagaolemiao dikes emplaced at ca. 242 Ma and the Tuilamamiao dikes emplaced at ca. 250 Ma, which postdated the Late Permian magmatic lull and convergent events in the SE CAOB. Dikes from the two areas are I-type rhyolitic rocks and exhibit high SiO2, low MgO, and low Cr, Co, and Ni contents. The Tagaolemiao dikes have depleted zircon Hf (epsilon Hf(t) = +3.75 to +9.82), whole-rock Sr - Nd (ISr(t) = 0.704340-0.704855; epsilon Nd(t) = +1.3 to +2.1) isotopic composition and variable zircon 818O values (4.88-7.29%o), and were derived from the mixing melts of the juvenile crust and depleted mantle. In contrast, the dikes from Tuilamamiao show negative zircon epsilon Hf(t) (-2.33 to -10.85) and whole-rock epsilon Nd(t) (-6.7 to -15.5) values, low ISr(t) (0.706640-0.708208) and high 818O (6.38-7.61%o) values, which originated from the partial melting of the old continental lower crust. The Triassic dyke swarms from this work indicate the SE CAOB switched into an intra-continental extension tectonic setting after the Paleozoic long-term accretion-convergence. |
| URI | http://hdl.handle.net/20.500.11897/626399 |
| ISSN | 0024-4937 |
| DOI | 10.1016/j.lithos.2021.106471 |
| Indexed | SCI(E) |
| Appears in Collections: | 造山带与地壳演化教育部重点实验室 地球与空间科学学院 |
