广西南宁盆地渐新世孢粉植物群及其古环境意义  

OLIGOCENE PALYNOFLORA FROM NANNING BASIN IN GUANGXI AND ITS PALAEOENVIRONMENTAL SIGNIFICANCE

作　　者：王伟铭[1] 陈耿娇 廖卫 

机构地区：[1]中国科学院南京地质古生物研究所,资源地层学与古地理学重点实验室,南京210008 [2]广西自然博物馆,南宁530012

出　　处：《第四纪研究》2015年第3期650-659,共10页Quaternary Sciences

基　　金：国家自然科学基金项目（批准号：41472010）和广西自然科学基金项目（批准号：2013GX、NSFAA019284）共同资助

摘　　要：文章系统研究南宁盆地琅东高坡邕宁组下含煤段的孢粉,建立1个孢粉组合和3个亚组合.孢粉组合以木本被子植物蕈树科、壳斗科、榆科、胡桃科、杨柳科和木犀科为主,同时见有槭树科、桦木科、芸香科、漆树科、椴树科、冬青科、大戟科、山龙眼科、楝科、珙桐科、忍冬科、山矾科和桑寄生科等成分;草本被子植物花粉少量见到,含莎草科、毛茛科、唇形科、禾本科、菊科、百合科、蓼科、黑三棱科和睡莲科;裸子植物花粉主要为杉科和松科,少量见到罗汉松科;蕨类植物孢子包括凤尾蕨科、水龙骨科、紫萁科、石松科、水藓科和海金沙科.此外,还见有部分藻类分布,含疑源类的皱面球藻属、瘤面球藻属和光面球藻属,亲缘关系不明的环纹藻属以及绿藻门水网藻科的盘星藻属.组合中,裸子植物花粉尤其松科的含量自下而上逐渐减少,藻类主要分布在剖面的中部,蕨类植物孢子更多地见于剖面的上部;因此进而分出3个亚组合.孢粉植物群反映沉积时期的气候温暖湿润,植被类型为亚热带湿生常绿、落叶阔叶混交林.结果表明当时的植物生境稳定、气候温暖,湖泊和湿地逐步发育,在后期形成沼泽环境;孢粉组合一定程度上反映了全球气候在始新世末期急剧变冷后,在渐新世早中期的逐渐回暖过程.A systematic study on spores and pollen grains in the lower coal bearing member of the Oligocene Yongning Formation at Langdonggaopo in Nanning Basin is carried out.The study site is located at NE Nanning City with the geographic coordinates of 22°49＇39.5＂N, 108°25＇19.7＂E.Thickness of the profile is around 7m, mainly consisting of mudstone, silty mudstone and siltstone.A total of 67 genera are recognized in 8 samples including spores, pollen grains and algae.One palynological assemblage and three subassemblages are established.Palynological assemblage is mainly characterized by Altingiaceae, Fagaceae, Ulmaceae, Juglandaceae, Salicaceae and Oleaceae, along with some small amount of Aceraceae, Betulaceae, Rutaceae, Anacardiaceae, Tiliaceae, Aquifoliaceae, Euphorbiaceae, Proteaceae, Meliaceae, Nyssaceae, Caprifoliaceae, Symplocaceae and Loranthaceae in woody angiosperms, and a small amount of herbaceous angiosperms including Cyperaceae, Ranunculaceae, Labiatae, Poaceae, Asteraceae, Liliaceae, Polygonaceae, Sparganiaceae and Nymphaeaceae.There are a certain amount of gymnosperms, mainly including Taxodiaceae and Pinaceae, and a few of Podocarpaceae.Pteridophytes consist of Pteridaceae, Polypodiaceae, Osmundaceae, Lycopodiaceae, Sphagnaceae, Lygodiaceae.In addition, there are also some algae, including Rugasphaera, Verrucosphaera, Leiosphaeridia in acritarchs, Concentricystis with unknown affinity, and Pediastrum belonging to Hydrodictyaceae in Chlorophyta.The contents of gymnosperm pollen, especially Pinaceae decrease gradually from bottom to top, and algae mainly occur in the middle part, while fern spores are more often found in the upper part of the profile.The palynological assemblage can thus be further divided into three subassemblages.This palynoflora reveals a warm and humid climate during the depositing period, with a vegetation type of subtropical wet evergreen, and deciduous broad-leaved mixed forest.The environment at that time was stable, and climate was warm.Lakes and wetlands gradually got fu

关 键 词：孢粉植物群 邕宁组 渐新世 气候环境 南宁盆地 

分 类 号：Q913.84[天文地球—古生物学与地层学] P532[生物学—古生物学]