火山地层界面的类型、特征和储层意义  

Types and Characteristics of Volcanostratigraphic Boundary and Its Signification of Reservoirs

作　　者：唐华风[1] 孙海波[1] 高有峰[1] 衣健[1] 姚瑞士[1] 

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《吉林大学学报（地球科学版）》2013年第5期1320-1329,共10页Journal of Jilin University：Earth Science Edition

基　　金：国家"973"计划项目(2009CB219303;2012CB822002);国家自然科学青年基金项目(41002038)

摘　　要：按照火山地层界面的形成过程和地质属性将其划分为5类,分别为喷发整合、喷发不整合、喷发间断不整合、构造不整合和侵入接触,除侵入接触外,其他不整合均可细分为角度不整合和平行不整合两种。喷发整合和喷发不整合两类界面上下岩层的间断为数分钟一数年,并且在界面上下均具有冷凝表壳或细火山碎屑层等,喷发不整合可为平行面状或交织曲面状,多为凹凸不平,分布范围小;喷发间断不整合界面形成时间为数十年一数千年,界面之下冷凝表壳或细碎屑层等明显遭受侵蚀,在横向上存在风化壳-沉积岩夹层的组合形式,界面平面展布多为波状曲面;构造不整合与喷发间断不整合在特征上相似,但形成时间为数千年一数百万年,界面分布范围更大。东北地区中生代火山岩剖面揭示:在喷发整合/不整合界面附近原生孔隙发育,随着与界面距离的增加孔隙度变小;具有交织曲面状界面岩层的面孔率大,孔隙发育带厚度及其占岩层比例均大于平行面状界面岩层。盆内钻井资料揭示喷发间断/构造不整合界面之下发育大量的次生孔隙,可与原生孔隙组合使储层物性变好,但当原生孔隙未能保存时其储层物性变化难以预测。Except INB, the others unconformity boundaries can be divided into angular unconformity and paraconformity/angular unconformity. The time interval of ECB and EUB is from several minutes to years. There is chilling crust or fine pyroclastic layer above and below these surfaces. The two types boundaries maybe curve or netlike plane, coarse and small ranges distribution. The time interval of EIUB is from decades to thousands years. There is weathered crust underlying the EIUB, and sedimentary rock bed overlying the EIUB. In most time, the weathered crust and thin sedimentary bed associate together. The boundary is smooth curve plane. The characteristics of TUB are similar to EIUB＇s. The interval time of TUB is from thousands to millions years, and the distribution scale is bigger than EIUB＇s. The Mesozoic volcanic rocks of NE China reveal that there is high porosity zone （mainly contribute by the primary pore） near the EUB or EIUB, and the porosity decreases when it is apart from the boundary. Both porosity and the percentage of pore rich rock of netlike boundary are higher than the curved boundary＇s. The wells in Songliao basin show that there is abundant secondary pore below theEIUBor TUB. Its porosity may be enhanced when the primary pores exit. On the other hand, it is difficuh to predict the change of porosity. Key words： volcanostratigraphical boundary; unconformity boundary; geological attributions; Northeast part of China; Mesozoic; volcanic rocks

关 键 词：火山地层界面 不整合界面 地质属性 东北地区 中生代 火山岩 

分 类 号：P618.13[天文地球—矿床学] P588.1[天文地球—地质学]