摘要
对北部湾盆地涠西南凹陷WZ5-X-Y井85份沉积样品开展了孢粉和藻类分析,探讨了钻孔所在区域古近纪—新近纪沉积环境的变化和植被类型的演替,并推断了气候条件的变化。研究结果显示,钻孔所在区域始新世—渐新世古湖泊发育,水域范围存在波动,渐新世整体上湖泊水域范围有所收缩,中新世湖泊进一步收缩,并持续受到海水入侵的影响。始新世钻井周边丘陵和低山地区发育以常绿栎和胡桃为主的常绿落叶阔叶混交林,湖泊周边生长桤木林,气候温暖湿润,渐新世的植被类型仍是以常绿落叶阔叶混交林为主,但是常绿林的缩小和针叶林的扩张则指示气温和湿度下降,中新世常绿林的扩张则指示了温度和湿度回升。
Changes in palaeoenvironment and palaeovegetation,and implications for climatic fluctuations were discussed in this paper,based on micropaleontological fossils including spores,pollen,freshwater algae and dinoflagellates cysts from the Well WZ5-X-Y which is located in the Weixinan Depression of Beibuwan Basin.Results suggest that the study area was a palaeolake during the study period.The lake shrank in Neogene but invaded by sea water in Miocene.The Paleogene vegetation was dominated by evergreen deciduous broadleaved forest,indicating a warm and humid climate condition,while the expansion of coniferous forest and contraction of evergreen broadleaved forest during Neogene suggest the decline of the temperature and humidity.The relatively wide distribution of evergreen broadleaved forest during Miocene indicate the improvement of the climate conditions.
作者
李君
王任
覃军干
邱琨祁
LI Jun;WANG Ren;QIN Jungan;QIU Kunqi(China National Offshore Oil Corporation,EnerTech-Drilling&Production Co.,Zhanjiang 524057,China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2020年第2期29-36,共8页
Marine Geology & Quaternary Geology
基金
中海油能源发展股份有限公司工程技术湛江分公司直属单位级项目“涠西南凹陷生物地层格架及地质意义”(GCJSXMHTF1706)
广东省软科学研究计划项目“广东省海上高温高压油气藏勘探开发企业重点实验室”(2018B030323028)。
关键词
孢粉
藻类
古环境
古植被
古气候
涠西南凹陷
spores and pollen
freshwater alga dinoflagellates cysts
palaeoenvironment
palaeovegetation
palaeoclimate
Weixinan Depression
