地质通报Issue(10)：1473-1481,9.
松辽盆地长岭断陷晚中生代火山岩SHRIMP锆石U-Pb测年、Hf同位素组成及其地质意义
Zircon SHRIMP dating and Hf isotope compositions of Late Me-sozoic volcanic rocks from Changling fault depression, Songliao Basin, and their geological implications
摘要
Abstract
SHRIMP U-Pb geochronology and in situ Lu-Hf isotope have been measured to constrain the timing of the two late-Mesozoic volcanic rock samples from the southern Changling fault depression, Northeast China. The Huoshiling Formation volcanic rock yielded a U-Pb age of 125.3Ma±1.1Ma, younger than the previous K-Ar system ages, suggesting that the volcanic rocks erupt-ed simultaneously in the southern and northern Songliao Basin. The analyzed zircons from Huoshiling volcanic rocks yielded the εHf(t) values between 2.0 and 8.1, which demonstrates that their parent magmas were derived from juvenile crust. The basement volcanic rocks yielded a U-Pb age of 173.6Ma±1.7Ma and theεHf(t) values between-8.8 and+1.5, which indicates the mixing of the juvenile and the pre-existent ancient crust. TheεHf(t) values in this study are obviously similar to those of the coeval zircons from the eastern Xing-Meng orogenic belt, suggesting that they might have originated from a common source. In the detrital zircons age spectrum, the ca. 171~176Ma peaks were recorded in the Late-Mesozoic sedimentary strata both from Taiwan and Northeast China, which can be interpreted as the start of the subduction of the Paleo-Pacific Block to the Eurasia Block. It is also inferred that the magmatism was widely distributed at the eastern edge of Eurasia, including coastal areas of Southeast China, southern Korean Peninsula and Northeast China.关键词
松辽盆地/长岭断陷/火石岭组/SHRIMP年龄/Hf同位素/古太平洋Key words
Songliao basin/Changling fault depression/Huoshiling Formation/SHRIMP age/Hf isotope/Paleo-Pacific分类
天文与地球科学引用本文复制引用
袁伟,徐旭辉,陆建林,杨振宇,王保华,朱建锋..松辽盆地长岭断陷晚中生代火山岩SHRIMP锆石U-Pb测年、Hf同位素组成及其地质意义[J].地质通报,2014,(10):1473-1481,9.基金项目
中国石化股份公司科技开发部项目 （）
