焦作市中更新世以来的孢粉组合与气候演化规律

发布时间：2018-05-03 06:34

  本文选题：孢粉 + 气候演化　； 参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：随着自然灾害的频繁发生,地震预测越来越重要。本文所依托项目《焦作市活动断层探测与地震危险性评价》的研究目标是探明焦作市目标区是否存在隐伏地震活动断层,并在目标区新构造单元开展代表性钻孔探测。本文以项目中河南省焦作市控制性标准钻孔(BK2孔)探测为出发点,利用孢粉组合特征,根据古植物演化规律,对河南省焦作市中更新世以来的气候做出鉴定,并且将其结果与全球气候变化进行对应。同时,文章结合钻孔测年数据、岩石特征、粒度特征等数据,对孢粉资料进行了对比分析,得出以下结论:⑴河南省焦作市的孢粉组合可以分为5个孢粉组合带和4个孢粉组合亚带:孢粉组合带Ⅰ指示了针阔混交林-草原的植被类型,反映了温暖偏干的气候特征;孢粉组合带Ⅱa指示了针阔混交林-草原的植被类型,反映了温凉偏干的气候特征;孢粉组合带Ⅱb指示了针阔混交林-草原的植被类型,反映了温暖湿润的气候特征;孢粉组合带Ⅲa指示了针阔混交林-草原的植被类型,反映了寒冷偏湿的气候特征;孢粉组合带Ⅲb指示了针阔混交林-草原的植被类型,反映了温暖湿润的气候特征;孢粉组合带Ⅳ指示了针叶林-草原植被类型,反映了寒冷干燥的气候特征;孢粉组合带Ⅴ指示了针阔混交林植被类型,反映了温暖湿润的气候特征。⑵将BK2孔的孢粉组合与深海氧同位素进行对比,可以看出焦作市的植被类型与契合特征受冰期和间冰期影响深远。焦作市更新世针阔混交林-草原和针叶林-草原的交替出现,与MIS7-MIS1暖冷暖冷的间冰期冰期交替气候相对应,但更新世中期焦作地区偏干,地区湿度与全球湿度的对应不太好;进入全新世后,植被繁盛,总体是针阔混交林,代表了冰后期的暖期气候,与全球气候特征相关。
[Abstract]:With the frequent occurrence of natural disasters, earthquake prediction is becoming more and more important. The research goal of the project "active fault detection and seismic risk assessment in Jiaozuo City" is to find out whether there are hidden seismicity faults in the target area of Jiaozuo City, and to carry out representative borehole exploration in the new structural unit of the target area. Based on the exploration of the control standard BK2 hole in Jiaozuo City, Henan Province, the climate since the Middle Pleistocene in Jiaozuo City, Henan Province, has been identified by using the characteristics of sporopollen assemblage and according to the evolution law of paleoplants. And the results are matched by global climate change. At the same time, combining with the data of borehole dating, rock characteristics and granularity, the paper makes a comparative analysis of the sporopollen data. The following conclusions can be drawn: 1 the sporopollen assemblages in Jiaozuo City, Henan Province can be divided into 5 sporopollen assemblage zones and 4 sporopollen assemblage subzones: the sporopollen assemblage zone 鈪，

本文编号：1837425