准噶尔盆地东部火烧山地区平地泉组方沸石特征及成因分析
发布时间：2018-10-30 13:39
【摘要】：火烧山所处的准噶尔盆地东部地区在晚石炭世至早中二叠世为陆内断陷-裂谷构造环境。火烧山地区二叠系平地泉组致密油具有较好的开发前景,笔者所在课题组经详细研究发现,其储层岩石除正常碎屑岩,还存在大量凝灰岩、沉凝灰岩,并见霓石、霓辉石、硅钡钛石等碱性岩矿物。岩心取样见方沸石分布广泛,含量、产状丰富。本文通过矿物学、岩石学和地球化学等综合研究,探讨了不同类型的方沸石成因。镜下系统观察鉴定,方沸石多呈纹层状、块状、脉状、球粒状、鲕粒状、斑块状产出,也见少量光性异常、生物介壳充填等类型方沸石。方沸石颗粒见大量自形-半自形晶,晶面干净,与晶外细粒沉积物接触截然,共生矿物有方解石、白云石、碱性长石、石英、氟碳铈矿等。方沸石主要赋存于凝灰岩、沉凝灰岩、白云岩、灰岩与方沸石岩(方沸石含量50%)中。经探针分析,方沸石Na_2O、Al_2O_3、SiO_2的平均含量分别为10.52%、20.21%、57.22%,与标准方沸石成分接近,具有低Si、高Na的特点,与之共生的碳酸盐矿物均富集热水沉积的Sr、Mn等元素。参照不同成因方沸石成分,对比方沸石阳离子数计算所得Xsi值和Si/Al值,本区方沸石具有岩浆-热液、火山沉积物转化成因的特征。地球化学分析表明,方沸石的赋存岩石主量元素比值SiO_2/Al2O3、SiO_2/(K2O+Na_2O)和SiO_2/MgO,微量元素及其判别图解,富集LREE和ΣREE,明显的Eu负异常、轻度Ce正异常均显示沉积物主要源于火山碎屑、具有热水沉积成因的特征,并形成于缺氧的还原环境。经综合研究,本文认为研究区方沸石存在热水沉积、内生岩浆-热液、沉积成岩三种成因,主体经历了以岩浆-热液和水热合成作用为主的热液喷流沉积作用。
[Abstract]:From late Carboniferous to early Middle Permian, the eastern area of Junggar basin is an intracontinental fault-rift tectonic environment. The dense oil of the Permian Pingdiquan formation in Huozaoshan area has a good prospect of development. The author's research group has found that in addition to the normal clastic rock, there are a large number of tuff, and aegirite, aegirite and pyroxene in the reservoir rocks. Basic rock minerals such as silica-barium titanite. The core samples are widely distributed, rich in content and rich in occurrence. Based on mineralogical, petrological and geochemical studies, this paper discusses the genesis of different types of donites. According to the systematic observation and identification under the microscope, most of the donalites were laminated, massive, veined, spherical, oolitic, plaques, and a small amount of photogenic anomalies were also found, as well as biological mesenchymal filling and other types of clinoptilolite. A large number of eutectic-semi-automorphic grains are found in donalite particles with clean crystal face and contact with fine sediments. The symbiotic minerals include calcite dolomite alkaline feldspar quartz fluorocarbon and so on. It mainly occurs in tuff, dolomite, limestone and analite (50% content of donite). By probe analysis, the average content of Na_2O,Al_2O_3,SiO_2 was 10.52%, 20.21% and 57.22%, which was close to that of standard zeolite, and had the characteristics of low Si, and high Na. The carbonate minerals are rich in Sr,Mn and other elements deposited by hot water. According to the composition of different genetic andesites, compared with the Xsi and Si/Al values calculated by the cationic number of donites, the clinoptilolite has the characteristics of magmatic hydrothermal and volcanic sediment transformation genesis. Geochemical analysis shows that the major element ratios SiO_2/Al2O3,SiO_2/ (K2O Na_2O) and SiO_2/MgO, trace elements and their discriminant diagrams of the host rocks of donalite are enriched in the negative Eu anomalies of LREE and 危 REE,. Mild Ce positive anomalies show that sediments are mainly derived from pyroclasts, characterized by hydrothermal deposition, and formed in anoxic reduction environment. Based on the comprehensive study, it is considered that there are three types of genesis in the study area: hydrothermal deposition, endogenetic magmatic hydrothermal solution and sedimentary diagenesis, the main body of which is hydrothermal jet deposition with magmatic hydrothermal and hydrothermal synthesis.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P578.974
，
本文编号：2300154
[Abstract]:From late Carboniferous to early Middle Permian, the eastern area of Junggar basin is an intracontinental fault-rift tectonic environment. The dense oil of the Permian Pingdiquan formation in Huozaoshan area has a good prospect of development. The author's research group has found that in addition to the normal clastic rock, there are a large number of tuff, and aegirite, aegirite and pyroxene in the reservoir rocks. Basic rock minerals such as silica-barium titanite. The core samples are widely distributed, rich in content and rich in occurrence. Based on mineralogical, petrological and geochemical studies, this paper discusses the genesis of different types of donites. According to the systematic observation and identification under the microscope, most of the donalites were laminated, massive, veined, spherical, oolitic, plaques, and a small amount of photogenic anomalies were also found, as well as biological mesenchymal filling and other types of clinoptilolite. A large number of eutectic-semi-automorphic grains are found in donalite particles with clean crystal face and contact with fine sediments. The symbiotic minerals include calcite dolomite alkaline feldspar quartz fluorocarbon and so on. It mainly occurs in tuff, dolomite, limestone and analite (50% content of donite). By probe analysis, the average content of Na_2O,Al_2O_3,SiO_2 was 10.52%, 20.21% and 57.22%, which was close to that of standard zeolite, and had the characteristics of low Si, and high Na. The carbonate minerals are rich in Sr,Mn and other elements deposited by hot water. According to the composition of different genetic andesites, compared with the Xsi and Si/Al values calculated by the cationic number of donites, the clinoptilolite has the characteristics of magmatic hydrothermal and volcanic sediment transformation genesis. Geochemical analysis shows that the major element ratios SiO_2/Al2O3,SiO_2/ (K2O Na_2O) and SiO_2/MgO, trace elements and their discriminant diagrams of the host rocks of donalite are enriched in the negative Eu anomalies of LREE and 危 REE,. Mild Ce positive anomalies show that sediments are mainly derived from pyroclasts, characterized by hydrothermal deposition, and formed in anoxic reduction environment. Based on the comprehensive study, it is considered that there are three types of genesis in the study area: hydrothermal deposition, endogenetic magmatic hydrothermal solution and sedimentary diagenesis, the main body of which is hydrothermal jet deposition with magmatic hydrothermal and hydrothermal synthesis.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P578.974
，
本文编号：2300154
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