SIMS U-Pb dating of rutile within eclogitic xenoliths in the Early Cretaceous adakitic rocks of the Xuzhou-Huaibei area, China: Constraints on the timing of crustal thickening of the eastern North China Craton  

作　　者：XIONG BoQin XU WenLiang LI QiuLi YANG DeBin ZHOU QunJun 

机构地区：[1]College of Earth Sciences, Jilin University [2]State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences [3]State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences

出　　处：《Science China Earth Sciences》2015年第7期1100-1106,共7页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.41222023);National Basic Research Program of China(Grant No.2015CB856101)

摘　　要：This paper reports the results of secondary ion mass spectrometry （SIMS） U-Pb dating of rutile within eclogitic xenoliths from the Early Cretaceous adakitic rocks in the Xuzhou-Huaibei area of China and discusses the geological significance of these new dates. The dating of rutile from pargasite-bearing eclogite and garnet clinopyroxenite （retrograde eclogite） yielded ages of 209 ± 25 and 132 ± 7 Ma, respectively. The former is consistent with the timing of the first stage of exhumation of the Dabie-Sulu orogenic belt and provides evidence of crustal thickening within the southeastern margin of the North China Cra- ton during the early Mesozoic, related to subduction and collision between the Yangtze and North China cratons. The latter age is similar to the timing of emplacement of the hosting intrusion and indicates that the rutile U-Pb system was triggered after uplifting by the intrusion of the hosting magmas. It implies that garnet clinopyroxenite was previously at the depth where the temperature was above the futile U-Pb closure temperature.This paper reports the results of secondary ion mass spectrometry(SIMS) U-Pb dating of rutile within eclogitic xenoliths from the Early Cretaceous adakitic rocks in the Xuzhou-Huaibei area of China and discusses the geological significance of these new dates. The dating of rutile from pargasite-bearing eclogite and garnet clinopyroxenite(retrograde eclogite) yielded ages of 209 ± 25 and 132 ± 7 Ma, respectively. The former is consistent with the timing of the first stage of exhumation of the Dabie-Sulu orogenic belt and provides evidence of crustal thickening within the southeastern margin of the North China Craton during the early Mesozoic, related to subduction and collision between the Yangtze and North China cratons. The latter age is similar to the timing of emplacement of the hosting intrusion and indicates that the rutile U-Pb system was triggered after uplifting by the intrusion of the hosting magmas. It implies that garnet clinopyroxenite was previously at the depth where the temperature was above the rutile U-Pb closure temperature.

关 键 词：North China Craton crustal thickening eclogitic xenoliths RUTILE SIMS U-Pb dating 

分 类 号：P542[天文地球—构造地质学] P588.3[天文地球—地质学]