沈北煤田煤中琥珀的植物来源和稳定同位素的古环境意义  

Botanical origin and palaeoenvironmental significance of stable isotopes of amber in coal from the Shenbei coalfield

作　　者：刘帮军 田泽奇 李鸿豆 郭旭 赵巧静 石志祥 郭文牧 张宁 AchimBECHTEL Maksim GBLOKHIN 孙玉壮 赵存良 LIU Bangjun;TIAN Zeqi;LI Hongdou;GUO Xu;ZHAO Qiaojing;SHI Zhixiang;GUO Wenmu;ZHANG Ning;Achim BECHTEL;Maksim G BLOKHIN;SUN Yuzhuang;ZHAO Cunliang(School of Earth Science and Engineering,Hebei University of Engineering,Handan,Hebei 056038,China;Key Laboratory of Resource Exploration Research of Hebei Province,Handan,Hebei 056038,China;Collaborative Innovation Center for Com prehensive Development and Utilization of Coal Resources in Hebei Province,Handan,Hebei 056038,China;School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Liaoning Geological Mining Group,Energy Geology Co.LTD,Shenyang,Liaoning 110o00,China;Department of Applied Geosciences and Geophysics,Montanuniversitat Leoben,Peter-Tunner-Strasse 5,Leoben 8700,Austria;Far East Geological Institute,Far Eastern Branch of Russian Academy of Sciences,Vladivostok 690022,Russia)

机构地区：[1]河北工程大学地球科学与工程学院,河北邯郸056038 [2]河北省资源勘测重点实验室,河北邯郸056038 [3]河北省煤炭资源综合开发与利用协同创新中心,河北邯郸056038 [4]中国矿业大学资源与地球科学学院,江苏徐州221116 [5]辽宁省地矿集团能源地质有限责任公司,辽宁沈阳110000 [6]莱奥本矿业大学应用地球科学与地球物理系,奥地利莱奥本8700 [7]俄罗斯科学院远东分院远东地质所,俄罗斯海参崴690022

出　　处：《地质学报》2023年第8期2445-2458,共14页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号42102215,42002192);河北省自然科学基金杰出青年基金项目(编号D2021402017)联合资助的成果。

摘　　要：琥珀是由古代植物代谢产生的树脂聚合物形成的化石。琥珀中的有机质保存环境稳定、封闭,能很好地记载其形成时期的古植物和古环境等信息。本次研究运用气象色谱质谱联用仪(GC-MS)和元素分析稳定同位素质谱仪(EA-IRMS)等测试方法,研究了沈北煤田煤中琥珀的有机地球化学组成、稳定同位素和化合物单体碳同位素特征。结果表明,琥珀中的饱和烃以二萜化合物为主(占73.45%),芳香烃以松香烷型化合物为主(56.17%);高含量的贝壳杉烷、雪松烷、扁枝烷和松香烷型化合物指示琥珀来源于松柏类植物,且以柏科植物为主。沈北琥珀的δ^(13)C值为-22.8‰~-21.2‰,与同时期其他地区琥珀的δ^(13)C值相似;氢同位素变化范围较小(-297.2‰~-276.0‰),氧同位素值为17.4‰~31.6‰。琥珀的稳定同位素组成(碳、氢和氧)进一步证明琥珀来源于裸子植物。琥珀的δ^(13)C值主要与其形成时的全球气温变化和大气组成有关。沈北琥珀的氢和氧同位素组成主要受植物种类(松柏类)以及植物生长的局部气温和降水条件有关。琥珀稳定碳同位素有望成为研究古气候和古大气组成的良好载体,琥珀的氢和氧同位素可以反映形成时期的古环境条件,但仍需进一步深入研究。Ambers are fossils formed from resinous polymers produced by the metabolism of ancient plants.The organic matter in amber is preserved in a stable and closed environment and could provide a good record of information about the ancient plants and palaeoenvironment during the formation of ambers.In this study,the organic geochemical composition,stable isotope and carbon isotope of individual compounds in ambers from the Shenbei coalfield were investigated using gas chromatography-mass spectrometry(GC-MS)and elemental analysis isotope ratio mass spectrometry(EA-IRMS).The results show that the saturated hydrocarbons in amber are dominated by diterpane compounds(73.45%)and the aromatic hydrocarbons are dominated by abietane-type compounds(56.17%);the high content ofkaurane,cedrane,phyllocladane,and abietane-type compounds indicate that ambers originated from conifers and are dominated by the Cupressaceae family.Theδ^(13) C values for ambers from the Shenbei coalfield are 22.8‰~21.2‰,similar to those of ambers from other regions of the same period;the hydrogen isotopes are less variable(297.2‰~276.0‰)and the oxygen isotope values range from 17.4‰to 31.6‰.The stable isotopic composition of amber(carbon,hydrogen,and oxygen)provides further evidence that amber is of gymnosperm origin.Theδ^(13)C values of amber are mainly related to global temperature variations and atmospheric composition at the time during its formation.The hydrogen and oxygen isotopic compositions of ambers from the Shenbei coalfield are mainly related to the plant species(Pinus)and the local temperature and precipitation conditions in which the plants grew.Stable carbon isotopes of ambers are expected to be a good indicator for the study of palaeoclimate and palaeo-atmospheric composition,and the hydrogen and oxygen isotopes of ambers may reflect paleoenvironmental conditions at the time of formation,but further research is needed on the stable isotope of ambers.

关 键 词：琥珀 碳同位素 植物来源 始新世 古环境 

分 类 号：Q914.2[天文地球—古生物学与地层学] P532[生物学—古生物学]