Detrital zircon dating and tracing the provenance of dinosaur bone beds from the Late Cretaceous Wangshi Group in Zhucheng, Shandong, East China  

作　　者：Wei An Hong-Wei Kuang Yong-Qing Liu Nan Peng Ke-Min Xu Huan Xu Peng Zhang Ke-Bai Wang Shu-Qing Chen Yan-Xia Zhang 

机构地区：[1]Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China [2]Shandong Institute of Geology Survey, Jinan 250000, Shandong, China [3]School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China [4]Dinosaur Research Center of Zhucheng, Zhucheng 262200, Shandong, China

出　　处：《Journal of Palaeogeography》2016年第1期72-99,共28页古地理学报（英文版）

基　　金：supported by the National Natural Science Foundation Projects(Grant No.41272021,41372109,90914003);China Geological Survey Project(Grant No. 1212011085477,12120114064301)

摘　　要：The mass burial of dinosaur bone fossils in the Late Cretaceous Wangshi Group in Zhu- cheng, Shandong Province has been a research focus in recent years. However, the prov- enance of the dinosaur bone fossils and the accurate depositional age of the bone beds remain ambiguous. Through U-Pb dating of detrital zircons collected from six conglom- erate samples from the dinosaur bone beds, we found that the youngest single grain age （YSG） of sample 090414-24-D was 77.3 Ma, representing the maximum depositional age of the dinosaur fossil beds and sediments. This also indicates that the Hongtuya Formation was deposited during the Campanian. Dating results revealed an age peak of 120 110 Ma, which corresponds with the peak age of volcanic rocks of the Lower Cretaceous Qingshan Group. The volcanic rocks of the Qingshan Group are mainly exposed in Laiyang, to the north of Zhucheng, although a few also appear to the south and northwest. Through analysis of conglomerate composition and palaeocurrents in the sediments containing the bone beds, we found that the three different data sets of gravel compositions of the con- glomerates were mainly composed of volcanic or pyroclastic rocks. Three different data sets of palaeocurrents suggested that the main sediment source of the Wangshi Group dinosaur bone beds was from the north-northwest of the Basin. Only one data set had a provenance south of the basin. This study revealed that the areas of Laiyang and the Yishu Fault Zone were the main provenance areas of both the dinosaur bone fossils and the sediments of the Wangshi Group in Zhucheng. The southern margin of the Zhucheng Basin may be a secondary source area. This research provides an important basis for judging the deposition time and the sediment source of fossil layers in the Wangshi Group, as well as reconstructing the palaeogeography of the Wangshi Group in the liaolai Basin.The mass burial of dinosaur bone fossils in the Late Cretaceous Wangshi Group in Zhu- cheng, Shandong Province has been a research focus in recent years. However, the prov- enance of the dinosaur bone fossils and the accurate depositional age of the bone beds remain ambiguous. Through U-Pb dating of detrital zircons collected from six conglom- erate samples from the dinosaur bone beds, we found that the youngest single grain age （YSG） of sample 090414-24-D was 77.3 Ma, representing the maximum depositional age of the dinosaur fossil beds and sediments. This also indicates that the Hongtuya Formation was deposited during the Campanian. Dating results revealed an age peak of 120 110 Ma, which corresponds with the peak age of volcanic rocks of the Lower Cretaceous Qingshan Group. The volcanic rocks of the Qingshan Group are mainly exposed in Laiyang, to the north of Zhucheng, although a few also appear to the south and northwest. Through analysis of conglomerate composition and palaeocurrents in the sediments containing the bone beds, we found that the three different data sets of gravel compositions of the con- glomerates were mainly composed of volcanic or pyroclastic rocks. Three different data sets of palaeocurrents suggested that the main sediment source of the Wangshi Group dinosaur bone beds was from the north-northwest of the Basin. Only one data set had a provenance south of the basin. This study revealed that the areas of Laiyang and the Yishu Fault Zone were the main provenance areas of both the dinosaur bone fossils and the sediments of the Wangshi Group in Zhucheng. The southern margin of the Zhucheng Basin may be a secondary source area. This research provides an important basis for judging the deposition time and the sediment source of fossil layers in the Wangshi Group, as well as reconstructing the palaeogeography of the Wangshi Group in the liaolai Basin.

关 键 词：Dinosaur bone beds Provenance Detrital zircon Geochronology Wangshi GroupShandong Zhucheng 

分 类 号：P534.53[天文地球—古生物学与地层学] Q915.2[天文地球—地质学]