准噶尔盆地中西部侏罗纪孢粉组分类型及基准面变化研究

发布时间：2018-07-12 20:31

本文选题：准噶尔盆地 + 侏罗纪　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：准噶尔盆地是位于我国西部的大型复合叠加含油气盆地之一。其中,侏罗纪地层是油气勘探的主要研究对象。侏罗纪时期,准噶尔盆地发育了丰富的河流、湖泊和沼泽相沉积。其中含有丰富的孢子、花粉及藻类化石。这些微体化石对地层划分对比及古植被古气候分析具有十分重要的意义,近年来人们又开始尝试用孢粉组分类型研究古水深及基准面旋回变化。本文通过对准噶尔盆地侏罗系孢粉化石与基准面变化关系的研究,取得以下主要成果和认识:(1)原理分析:孢粉一般都是异地埋藏的搬运化石集合,通过对孢子与花粉植被类型和组成构造的分析,认为二者具有不同的搬运方式,孢子一般为地表径流搬运,而花粉主要靠风力吹扬搬运,因此孢子与花粉、以及不同类型的花粉其搬运距离就各不相同,因而不同的水深就会有不同的孢粉组合。(2)方法探讨:考虑到孢粉类型的复杂多样性,通过对孢粉形态结构类型、复合分异度及组分类型3种不同方法研究古水深及基准面变化关系,并与沉积相研究结果进行对比,结果表明尽管三种方法均能建立孢粉旋回与基准面变化关系,但前2种方法仅反映古水深变化的趋势,而孢粉组分类型变化不但能很好地反映基准面变化旋回,且与沉积相类型具有一定的对应关系,效果最好。(3)具体研究:通过对6口井孢粉化石(141属229种)的详细鉴定及数量统计,分别计算各样品中孢粉形态结构类型(4种)、复合分异度及孢粉组分类型(3种)百分含量的井深变化,并与沉积相研究结果进行对比,结果表明孢粉组分类型与中、长期旋回具有良好的对应关系,在此基础上,通过井间对比,探讨了水深的横向变化。
[Abstract]:Junggar Basin is one of the large superimposed oil-gas basins located in the west of China. Jurassic stratigraphy is the main object of oil and gas exploration. During the Jurassic period, the Junggar Basin developed abundant fluvial, lacustrine and marsh facies deposits. It contains abundant spores, pollen and algae fossils. These microfossils are of great significance to stratigraphic division and correlation and paleovegetation paleoclimate analysis. In recent years, people have tried to study paleo-water depth and base-level cycle changes by using sporopollen component types. Based on the study of the relationship between Jurassic sporopollen fossils and datum level variation in Junggar Basin, this paper has obtained the following main achievements and understandings: (1) principle analysis: sporopollen is generally a collection of transporting fossils buried in different places. Based on the analysis of the type and composition of spore and pollen vegetation, it is concluded that there are different transport modes between spores and pollen. Spore is generally transported by surface runoff, while pollen is transported mainly by wind, so spore and pollen are transported by wind. The transportation distance of different pollen types is different, so different water depth will have different sporopollen combinations. (2) considering the complex diversity of sporopollen types, the morphological and structural types of pollen are analyzed. The relationship between paleo water depth and datum level was studied by three different methods of composite differentiation degree and composition type, and the results were compared with those of sedimentary facies. The results showed that although all three methods could establish the relationship between sporopollen cycle and datum level change, However, the former two methods only reflect the trend of paleo-water depth change, and the change of sporopollen composition can not only well reflect the base-level change cycle, but also have a certain correspondence with the sedimentary facies type. The results are the best. (3) specific study: through the detailed identification and quantitative statistics of 6 sporopollen fossils (141 genera 229 species), The variation of well depth of pollen morphology and structure type (4 kinds), composite differentiation degree and sporopollen component type (3%) in each sample were calculated, and the results were compared with those of sedimentary facies. The results showed that the sporopollen fractions were of middle and middle types. The long term cycle has a good corresponding relationship. On this basis, the horizontal variation of water depth is discussed by means of cross-well correlation.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q914;P534.52

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