摘要
以角质层保存完好的4种银杏类化石为研究对象,通过对叶片角质层气孔参数的详细统计分析,利用气孔指数法和气孔比率法,定量重建了该区中侏罗世阿林期一巴柔期古大气φ(CO_2).结果显示:通过气孔指数法获得的狭叶拟刺葵、西伯利亚似银杏、敏斯特里拜拉(相似种)、东北拜拉大气妒(CO_2)均落在GEOCARBⅢ可信误差范围之外,而气孔比率法获得的狭叶拟刺葵、西伯利亚似银杏、敏斯特里拜拉(相似种)、东北拜拉大气φ(CO_2)均落在GEOCARBⅢ可信误差范围之内.说明对于恢复侏罗纪的大气φ(CO_2)气孔比率法更加可靠.由气孔比率法所得的古大气φ(CO_2)中,西伯利亚似银杏所得结果最接近最佳拟合线,其次是狭叶拟刺葵,拜拉属植物所得结果较低.表明似银杏属植物化石获得的古大气φ(CO_2)更加准确.最后确定出内蒙古准格尔旗西南部中侏罗世阿林期-巴柔期的φ(CO_2)为1.413×10^(-3).
Using the method of stomatal index and stomatal radio,the stomatal parameters on the epidermis were studied,based on the materials of four species of ginkgo fossils from the study area,and the paleo-φ（CO2）concentrations from Aalenian to Bajocian in the middle Jurassic were reconstructed for Phoenicopsis angustifolia,Ginkgoites sibirica,Baiera cf.muensteriana and Baiera manchurica respectively by the stomatal index method,which was out of the error range of φ（CO2） confidence from GEOCARBⅢ.However,the values of paleo-φ（CO2） were obtained by using the method of stomatal ratio,which was plotted within the error range of φ（CO2） confidence.The two results indicated that the stomatal ratio method is more reliable than the stomatal index method in reconstructing Jurassic φ（CO2） concentration.For the paleo-φ（CO2）values obtained from the stomatal ratio method,Ginkgoites sibirica was more adjacent to the optimum line of GEOCARB Ⅲ.The second was Phoenicopsis angustifolia.The results of Baiera were lower,which were reconstructed respectively by Baiera manchurica and Baiera cf.müensteriana,suggesting that the paleo-φ（CO2）concentration reconstructed from ginkgoales fossils was more precise.As a result,the paleo-φ（CO2） concentration of the southwestern margin of Junger Banner,Inner Mongolia from Aalenian to Bajocian in the middle Jurassic is ascertained to be 1.413×10^-3.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第1期1-8,18,共9页
Journal of Lanzhou University(Natural Sciences)
基金
国家重点基础研究发展计划"973"项目(2012CB822003)
高等学校博士学科点专项科研基金项目(20120211110022)
2014国家质量工程大学生创新创业计划项目(201410730129)
作者简介
金培红（1989-），女，甘肃兰州人，博士研究生，e-mail：jinphl4@lzu．edu．cn，研究方向为古生物与地层学；
孙柏年（1955-），男，山东沂水人，教授，博士研究生导师，e-mail：bnsun@lzu．edu．cn，研究方向为古生物学与地层学，通信联系人．
