冀北四岔口盆地早白垩世大型恐龙化石赋存地层的有机碳同位素记录及其古环境意义  

The δ13CTOC Record of Early Cretaceous Strata Bearing Giant Dinosaurs in the Sichakou Basin, North Hebei Province, and Its Palaeoenvironmental Implication

作　　者：孙志超 赵艳 刘贺 任咣营 郭颖[1] 邵凤丽 王金玲 阎作均 王朝民 张福成 

机构地区：[1]临沂大学地质与古生物研究所,山东 临沂 [2]临沂大学生命科学学院,山东 临沂 [3]丰宁古生物化石博物馆,河北 承德

出　　处：《地球科学前沿（汉斯）》2021年第6期747-755,共9页Advances in Geosciences

摘　　要：依据化石产出地层沉积物的古环境重建可为相关古生物的研究提供较详细的背景支撑,但目前有关早期热河生物群的上述研究较少。河北省丰宁县的四岔口盆地早白垩世花吉营组地层埋藏有大型恐龙化石,本文对其中一处化石赋存层位的沉积物进行了有机碳含量(TOC)和总有机碳同位素组成(δ13CTOC)分析,结果表明沉积物的TOC和δ13CTOC值显著负相关,且δ13CTOC值整体显著偏轻。这表明当时冀北地区植物的δ13CTOC特征可能是受火山活动影响,即火山喷发释放CO2导致大气CO2的δ13C值变轻且CO2浓度增加,从而使植物的δ13CTOC值整体变轻;且随着植物生产力的增大,δ13CTOC值相对偏轻的陆生植物和/或挺水植物对湖泊沉积有机质的相对贡献量增加,δ13CTOC值相对偏重的沉水植物的相对贡献量减少。Palaeoenvironmental reconstruction based on the fossil-bearing sediments could provide the basic habitat support in acquiring the knowledge about the prehistoric remains. The similar studies, however, are few conducted in researches to the early Jehol Biota by now. In this preliminary study, the fossil-bearing sediments were collected first in northern Hebei, where lots of significant early birds and a well-preserved giant dinosaur were found, and the total organic carbon (TOC) and total organic carbon isotope composition (δ13CTOC) were analyzed later. The results show TOC and δ13CTOC values are significantly negatively correlated, and the δ13CTOC values are obviously lower. The volcanic activity during the Hauterivian period in north Hebei may account for the reducing of the sediment δ13CTOC values, for the large amount of CO2 erupted into the air would lighten the δ13C value in atmospheric CO2 which its concentration was increased at the same time, further leading to the overall reducing of δ13CTOC value in the contemporaneous plants. Besides, with the increase of plants productivity, the terrestrial and/or emergent plants, which the relative δ13CTOC values are usually lower, added more relative contribution to the limnetic organic materials, while those of submerged plants, which the relative δ13CTOC values are usually higher, added less.

关 键 词：四岔口盆地 花吉营组 有机碳同位素组成 古环境 热河生物群 

分 类 号：P61[天文地球—矿床学]