JOPC ›› 2021, Vol. 23 ›› Issue (5): 887-900. doi: 10.7605/gdlxb.2021.05.061

Special Issue: The Application of Fossil Data in Geological research

• BIOPALAEOGEOGRAPHY AND PALAEOECOLOGY • Previous Articles     Next Articles

Characteristics of stable carbon isotope of the Early Devonian plants from Yunnan Province and its palaeoclimatic significance

Zhang Shi-Hui1, Xiao Liang2, Xue Jin-Zhuang1, Meng Mei-Cen3, Qin Min4, Cui Ying5, Wang De-Ming1   

  1. 1 School of Earth and Space Sciences,Institute of Paleontology & Environmental Science, Peking University,Beijing 100871,China;
    2 School of Earth Science and Resources, Key Laboratory of Western Mineral Resources and Geological Engineering, Ministry of Education,Chang'an University,Xi'an 710054,China;
    3 Geological Branch of Science Press,Beijing 100717,China;
    4 Institute of Geology and Paleontology,Linyi University,Shandong Linyi 276000,China;
    5 Department of Earth and Environmental Studies,Montclair State University,Montclair,New Jersey 07043,USA
  • Received:2020-12-31 Revised:2021-03-19 Online:2021-10-01 Published:2021-09-29
  • Contact: Cui Ying,born in 1983,is an assistant professor at Montclair State University. She is mainly engaged in research of earth sciences. E-mail: cuiy@montclair.edu. Wang De-Ming,born in 1970,is a professor at Peking University. He is mainly engaged in research of palaeobotany.E-mail: dmwang@pku.edu.cn.
  • About author:Zhang Shi-Hui,born in 1995,is a postgraduate in School of Earth and Space Sciences,Peking University. He is mainly engaged in research of palaeoenvironment. E-mail: zsh16390@163.com.
  • Supported by:

    ; Financially supported by the National Natural Science Foundation of China(Nos. 42072016,41872017)

云南早泥盆世植物稳定碳同位素特征及其古气候意义*

张世辉1, 肖良2, 薛进庄1, 孟美岑3, 秦敏4, 崔莹5, 王德明1   

  1. 1 北京大学地球与空间科学学院,史前生命与环境科学研究所,北京 100871;
    2 长安大学地球科学与资源学院,西部矿产资源与地质工程教育部重点实验室,陕西西安 710054;
    3 科学出版社地质分社,北京 100717;
    4 临沂大学地质与古生物研究所,山东临沂 276000;
    5 蒙特克莱尔州立大学地球与环境研究系,美国新泽西州蒙特克莱尔 07043
  • 通讯作者: 崔莹,女,1983年生,蒙特克莱尔州立大学助理教授,主要从事地球科学研究。E-mail: cuiy@montclair.edu。王德明,男,1970年生,北京大学教授,主要从事早期陆生植物研究。E-mail: dmwang@pku.edu.cn。
  • 作者简介:张世辉,男,1995年生,北京大学地球与空间科学学院硕士研究生,主要从事古环境研究。E-mail: zsh16390@163.com。
  • 基金资助:

    *国家自然科学基金项目(编号: 42072016,41872017)资助

Abstract:

Because of the availability of plant fossil materials in the deep past,palaeoenvironment inversion using δ13C value of Paleozoic plant fossils is relatively poorly studied. In this paper,the stable carbon isotopes of some fossil plants are analyzed from the Lower Devonian Xujiachong Formation in Qujing area and from the Posongchong Formation in Wenshan area,Yunnan Province,China. The δ13C values of Drepanophycus from the Xujiachong Formation range from-29.0‰ to -22.8‰ with an average value of-24.5‰. The δ13C values of Zosterophyllum and Eophyllophyton from the Posongchong Formation range from -24.8‰ to -22.1‰ and -23.0‰ to -22.6‰,and their average values are -23.2‰ and -22.7‰,respectively. All values fall within the distribution range of the δ13C values of modern C3 plants. The δ13C values of different organs of Drepanophycus are dissimilar,and the δ13C value of the axis is 0.1‰ to 0.3‰ higher than that of the leaf. From the 57th to the 79th sedimentary cycles of the Xujiachong Formation,the δ13C value of Drepanophycus increases by about 2‰,which is interpreted as relating to a decrease in the palaeoatmospheric CO2 concentration and to the climate cooling. The calculated Ci/Ca values of Drepanophycus and Zosterophyllum are relatively stable across the studied interval. Thus,it is inferred that these two plants are sensitive to the change of palaeoatmospheric CO2 concentration and the palaeoclimate in Qujing area may be the present tropical savanna climate or tropical monsoon climate.

Key words: Yunnan Province, Early Devonian, plant fossil, stable carbon isotope, palaeoenvironment

摘要:

受到植物化石材料局限性与时代久远性的限制,目前用古生代植物化石δ13C值来反演古环境的研究程度较低。文中通过对云南省曲靖市下泥盆统徐家冲组和文山州下泥盆统坡松冲组的部分植物化石进行稳定碳同位素测试,分析了早泥盆世植物的光合作用途径以及古环境。结果表明: 徐家冲组镰蕨属(Drepanophycus)δ13C值为-29.0‰~-22.8‰,平均值为-24.5‰,其中镰蕨属茎轴的δ13C值高于叶片0.1‰~0.3‰;坡松冲组工蕨属(Zosterophyllum)和始叶蕨属(Eophyllophyton)δ13C值分别为-24.8‰~-22.1‰和-23.0‰~-22.6‰,平均值分别为-23.2‰和-22.7‰;三者的δ13C值分布范围都与现代C3植物一致。自徐家冲组第57至第79沉积旋回,δ13C值总体呈上升趋势,达到2‰左右,推测可能与早泥盆世大气CO2浓度下降和气候变冷相关。镰蕨属和工蕨属的Ci/Ca值较为稳定,说明这2种植物可能对大气CO2浓度变化较为敏感,曲靖市古气候可能为当今的热带疏林草原气候或热带季风气候。

关键词: 云南, 早泥盆世, 植物化石, 稳定碳同位素, 古环境

CLC Number: