琼东南盆地新生代孢粉组合及其古气候意义  

NEOGENE PALYNOLOGICAL ASSEMBLAGES FROM QIONGDONGNAN BASIN AND THEIR PALEOCLIMATIC IMPLICATIONS

作　　者：张一凡[1,2] 刘东生[1] 张训华[2] 

机构地区：[1]中国海洋大学海洋地球科学学院,青岛266100 [2]青岛海洋地质研究所,青岛266071

出　　处：《海洋地质与第四纪地质》2017年第1期93-101,共9页Marine Geology & Quaternary Geology

基　　金："十二五"国家科技重大专项--"南海北部深水区潜在富生烃凹陷评价"子课题<南海西部深水区古气候与古环境研究>(2011ZX05025-002-03)

摘　　要：以琼东南盆地深水区LS33井岩心为研究对象,通过对孢粉组合序列的分析,探讨渐新世以来各个地质时期的植被类型以及所反映的古气候特征。根据孢粉谱和聚类分析结果,LS33井岩心可划分为8个孢粉组合,不同组合之间孢粉面貌差异巨大。早渐新世,孢粉组合中以蕨类植物为优势组分,多见常绿植物,代表冷干的植物分子罕见,反映了暖湿性的热带亚热带气候。晚渐新世到早中新世,延续了早渐新世暖湿的特点,常绿栎、榛最为繁盛,植被和气候出现较为明显的垂直分带性。早中新世研究区气候发生了重大转折,温带落叶树和高山针叶林树的增多表明气候类型已转至凉干。早中新世至晚中新世常绿树的繁盛和红树科的发育表明气候属于暖湿型。上新世到更新世继承了晚中新世的特点,但红树林逐渐衰退,草本植物逐渐繁盛,意味着气候类型从暖湿逐渐转为凉干。Palynological research plays a significant role in exploration for petroliferous basins. It provides not only evidence for stratigraphic classification, but also information on paleovegetation and paleoclimate.With the palynological assemblages of the Well LS33 from the deepwater area of the Qiongdongnan Basin, this paper discussed the paleovegetation types and paleoclimatie characteristics of the basin since Oligo- cene. Eight palynological assemblages are identified and variations in assemblages recognized. The Early Oligocene pollen assemblages is dominated by ferns, accompanied by evergreens, with little cool and dry species, representing a tropical or subtropical warm and humid climate. The Late Oligocene to Early Mio- cene assemblages inherited the warm and humid weather in Early Oligocene. Quercoidites and Momipites are most abundant, with more apparent vertical zonations in both vegetation and climate. However, a stunning change occurred in Early Miocene. An increasing in pollen assemblage of temperate deciduous forest and alpine coniferous forest suggests the climate conditions that changed dramatically to cool and dry. Evergreens and Mangrove were abundant in Early Miocene to Late Miocene, and the climate was warm and humid then. Since Late Miocene, mangrove gradually reduced while herbs increased, which il- lustrated a conversion from the warm and humid weather to the cool and dry again.

关 键 词：孢粉组合 古气候 新生代 琼东南盆地 

分 类 号：Q913[天文地球—古生物学与地层学]