| 辽西新台门白垩纪火山岩~(40)Ar/~(39)Ar定年及其对蝾螈化石层时代的约束 |
| |
| 引用本文： | 孙荣双,季建清,高克勤,张越,周晶,马芳,徐芹芹.辽西新台门白垩纪火山岩~(40)Ar/~(39)Ar定年及其对蝾螈化石层时代的约束[J].岩石学报,2010,26(11):3397-3410. |
| |
| 作者姓名： | 孙荣双 季建清 高克勤 张越 周晶 马芳 徐芹芹 |
| |
| 作者单位： | 北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室,北京,100871 |
| |
| 基金项目： | 本文受国家自然科学基金项目(40472100)资助. |
| |
| 摘 要： | 富含热河生物群鸟类和恐龙化石的辽西白垩纪地层属于中生代陆相火山沉积,其不同区域之间的地层对比和时代归属一直存有较大争议。本文采用激光40Ar/39Ar年代学方法,对葫芦岛新台门地区一个实测剖面中蝾螈化石点下伏的两层火山岩夹层进行了年代学研究。通过地层中火山岩夹层及火山岩颈的年代学测定,获得6组激光40Ar/39Ar年代结果。其中,下部层位中的流纹岩和安山质玄武岩样品XTM-3、XTM-5年龄结果分别为94.2±1.3Ma、93.7±1.3Ma;作为这一期喷发晚期就位的火山岩颈样品XTM-7的年龄结果为92.8±0.4Ma;而上部层位的安山岩和安山玄武岩火山岩夹层样品XTM-6、XTM-8、XTM-9年龄分别为110.1±1.0Ma、110.9±0.5Ma、93.7±1.2Ma。随后我们又从XTM-9位置的化石点下部采集样品XTM-9-2,进行实验验证。得到的结果表明,新台门地区早白垩世地层记录了至少两期火山喷发事件,喷发时间分别为110Ma和93Ma。根据测年结果,新台门白垩系的蝾螈化石层应代表中国北方中生代地层中迄今所发现的有尾两栖类化石纪录的最高层位,可能与辽西地区的九佛堂组或甚至与阜新组相当。
|
| 关 键 词： | 火山岩 40Ar/39Ar年代学 早白垩纪 辽西新台门 |
| 收稿时间： | 2009/4/15 0:00:00 |
| 修稿时间： | 2010/5/14 0:00:00 |
40Ar/39Ar dating of volcanic rocks and constraints for stratum age of Xintaimen area in western Liaoning. |
| |
| SUN RongShuang,JI JianQing,GAO KeQin,ZHANG Yue,ZHOU Jing,MA Fang and XU QinQin.40Ar/39Ar dating of volcanic rocks and constraints for stratum age of Xintaimen area in western Liaoning.[J].Acta Petrologica Sinica,2010,26(11):3397-3410. |
| |
| Authors: | SUN RongShuang JI JianQing GAO KeQin ZHANG Yue ZHOU Jing MA Fang and XU QinQin |
| |
| Institution: | Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China;Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China;Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China;Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China;Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China;Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China;Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China |
| |
| Abstract: | Mesozoic deposits in western Liaoning were celebrated for yielding abundant bird and feathered dinosaur fossils of the Jehol Biota. The age and stratigraphic correlations of the fossil beds in different areas and horizons, however, have been constantly in dispute. Results of laser 40Ar/39Ar dating of two sets of volcanic rock samples are presented in the paper to determine the age and stratigraphic sequence of the salamander fossil beds exposed near Xintaimen, Huludao City, western Liaoning. The rock samples XTM-3, XTM-5 from the lower part of the measured section were dated as 94.2±1.3Ma, 93.7±1.3Ma, respectively. The rock sample XTM-7 was dated as 92.8±0.4Ma, representing the sampling of a volcanic neck emplaced during the late stage of the eruption. Additional samples of XTM-6, XTM-8 and XTM-9 from the upper part of the section were dated as 110.1±1.0Ma, 110.9±0.5Ma and 93.7±1.2Ma, respectively. In order to validate the dating results, we test another sample XTM-9-2, which locates at the fossil point below the sample XTM-9. The dating results indicate that at least two separate eruption events can be recognized in Xintaimen area, with an early eruption at about 110Ma and a later one at 93Ma. According to the dating results, the salamander fossil bed at Xintaimen should be a counterpart of the Lower Cretaceous Jiufotang Formation or the Fuxin Formation, representing the highest salamander-bearing horizon ever known in the Mesozoic of northern China. |
| |
| Keywords: | Volcanic-rocks 40Ar/39Ar Dating Early Cretaceous Xintaimen western Liaoning |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《岩石学报》浏览原始摘要信息 |
| 点击此处可从《岩石学报》下载免费的PDF全文 |
|
