Abstract: The lithochemical characteristics of Bikou Group,Pengguan complex rock and Kangding complex rock located in the north,east and south parts of Songpan-Aba Basin are very similar,which shows that the above three magmatic rocks originated from the same geological environment,and the tectonic events occurred in the Mesoproterozoic-Neoproterozoic period and involved the whole basin.The combination analysis of geophysical data,such as magneto-electro-telluric data,gravity data,and the lithochemical data confirm that there exists a stable basement in Songpan-Aba Basin.The hypometamorphic rock is distributed around the Ruoergai,and the epimetamorphic rock and the magmatic rock are distributed around the margin of the basin.The three intrusions mentioned above consist of stable basement.On the basis of solid basement,two plays of the Eopaleozoic and the Neopaleozoic-Triassic reservoirs were developed.The reservoir-forming condition of the Eopaleozoic play is better than that of the Neopaleozoic-Triassic play.The reservoir-forming condition in the middle uplift zone of the basin is the best.The Triassic formation is very thick,which results in the high exploration expenditure and risk in this area.Though the Motianling uplift only developed the Eopaleozoic play,the stable geological setting with weak tectonic activities since the Miocene time benefited to the preservation of petroleum.Therefore the Motianling uplift is an available exploration area in Songpan-Aba Basin.

Key words: Songpan-Aba Basin, basement, magmatic rock, lithochemical characteristics, reservoir-forming condition, petroleum exploration potential

摘要： 对松潘—阿坝盆地北部碧口群、东部龙门山彭灌杂岩和南部康定杂岩火成岩岩石化学特征的分析结果表明,三种岩石的化学特征比较相似,形成环境相同,说明中—晚元古代的这一期构造活动在盆地范围内具有普遍性.重磁电资料综合分析表明,盆地具有稳定基底,因而盆地后期构造演化环境相对稳定,形成了下古生界和上古生界—三叠系两套成藏组合,前者的成藏条件较优越.盆地中部隆起区油气成藏条件最好,但三叠系厚度太大,勘探成本与风险较高;而摩天岭隆起以下古生界成藏组合为主,后期构造活动对原生油气藏的破坏较小,具有一定的油气勘探远景.尽管后者的油气成藏条件不如盆地中部隆起区优越,但却是一个现实的勘探区域.

关键词: 松潘—阿坝盆地, 基底, 火成岩, 岩石化学特征, 成藏条件, 油气勘探远景