火山岩陆上与水下喷发环境的氧化系数判别方法  

Discrimination Methodof Oxidation Index of Volcanic Rock in Land and Underwater Eruption Environments

作　　者：伍宏美 陈亚军 孟朋飞 马强 宋小勇 何兴华 于家义 何伯斌 WU HongMei;CHEN YaJun;MENG PengFei;MA Qiang;SONG XiaoYong;HE XingHua;YU JiaYi;HE BoBin(China United Academy of Petroleum Sciences,Beijing 100101,China;Research Institute of Exploration and Development,Turpan Hami Oilfield Company,PetroChina,Hami,Xinjiang 839009,China;Research Institute of Exploration and Development,Yumen Oilfield Company,PetroChina,Jiuquan,Gansu 735019,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]北京中科联华石油科学研究院,北京100101 [2]中国石油吐哈油田分公司勘探开发研究院,新疆哈密839009 [3]中国石油玉门油田分公司勘探开发研究院,甘肃酒泉735019 [4]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵阳550081 [5]中国科学院大学,北京100049

出　　处：《沉积学报》2022年第3期599-615,共17页Acta Sedimentologica Sinica

基　　金：中国石油天然气股份公司重大科技专项(2016E-0203)。

摘　　要：火山喷发沉积期的古地理环境是控制火山岩油气储层发育的关键因素之一。目前对陆上喷发沉积火山岩与水下喷发沉积火山岩的判别研究主要集中在岩性组合特征、结构与构造特征、蚀变特征、产状、孔隙及裂缝发育特点等方面,而利用火山岩地球化学特征来反映和记录火山喷发环境的研究尚未引起注意。研究使用Fe_(2)O_(3)/FeO和Fe_(2)O_(3)/(Fe_(2)O_(3)+FeO)作为火山岩氧化系数,充分考虑岩石酸度、风化淋滤作用、溶蚀蚀变作用、构造背景等因素的影响,改进了传统意义上基于火山岩氧化系数的火山喷发环境判别标准。在新疆三塘湖盆地马朗凹陷上石炭统实际应用结果表明,卡拉岗组火山岩喷发沉积环境复杂,以陆上氧化环境为主,频繁水陆交替的复杂环境也存在,哈尔加乌组火山岩喷发沉积环境相对单一,主要沉积保存于水下还原环境;与前人基于本区上石炭统火山岩共生岩石与化石组合、风化壳以及火山岩夹持的部分泥岩微量元素比值特征等有效判别依据得到的喷发环境结果是相符的,且该地球化学方法具有普适性,可应用于不同盆地、不同地质时代火山岩喷发沉积古地理环境的判别研究中。Paleogeographic environment is one of the key factors controlling the development of volcanic oil and gas reservoirs.At present,the research on the discrimination between terrestrial and underwater eruptive sedimentary volcanic rocks mainly focuses on the characteristics of lithologic association,structural structure,alteration,occurrence,pore and fracture development,however,the study of using geochemical characteristics of volcanic rocks to reflect and record volcanic eruption environment has not been paid attention to.In this study,Fe_(2)O_(3)/FeO and Fe_(2)O_(3)/(Fe_(2)O_(3)+FeO)are used as the oxidation coefficients of volcanic rocks,and the influence of rock acidity,weathering leaching,dissolution and alteration,tectonic background and other factors are fully considered,which improves the traditional discrimination standard of volcanic eruption environment based on the oxidation coefficient of volcanic rocks.The results of practical application in Malang Sag of Santanghu Basin,Xinjiang show that,the sedimentary environment of volcanic eruption in Kalagang Formation is complex,which is mainly land oxidation environment,and the complex environment of frequent water land alternation also exists,and the eruptive deposits of the volcanic rocks in the Haerjiawu Formation are relatively single,and they are mainly deposited in an underwater reducing environment;the results are consistent with those obtained by predecessors on the basis of the combination of volcanic paragenetic rocks and fossils,weathering crust and trace element ratio characteristics of some mudstones sandwiched by volcanic rocks,also this geochemical method is universal,the Identification map can be used to distinguish the paleogeographic environment of volcanic eruption deposits in different basins and geological ages.

关 键 词：陆上沉积火山岩 水下沉积火山岩 氧化系数 古地理环境 马朗凹陷 上石炭统 

分 类 号：P595[天文地球—地球化学]