摘要
早泥盆世时东特提斯洋沿金沙江—哀牢山缝合带逐渐向东打开 ,广南—靖西等基底断裂与板块边界断裂——金沙江—哀牢山断裂带平行展布和同步演化 ,边界断裂的向东开裂扩张 ,广南—靖西等基底断裂活动亦逐渐加剧 ,导致右江盆地由陆内裂陷盆地向被动陆缘裂谷盆地演化。据构造活动的强弱和盆地充填物的特征 ,将右江盆地的演化分为洛赫科夫期至布拉格期的陆内裂陷盆地阶段、埃姆斯期—艾费尔期的拉张发展阶段、吉维期至弗拉斯期的强烈拉张阶段、法门期的充填补齐阶段 ,后三者组成被动陆缘裂谷盆地阶段。不同次级盆地的不同阶段 ,其构造沉降和海平面升降幅度不一样 ,层序发育样式各异 ,其中孤立碳酸盐岩台地层序发育主要受控于相对海平面变化和碳酸盐生产率 ,而台盆层序发育则受构造活动、海平面变化、台缘重力流和沉积物供应的综合影响。据此 ,将该区泥盆系划分为两个 级层序 ,18个 级层序 ,并建立了各演化阶段的层序充填模型。这种层序充填的差异性正是对盆地构造演化和全球海平面变化的响应。
Eastern Tethys Ocean unclosed along Jinshajiang-Ailao mountain suture zone in the Early Devonian, Guangnan-Jingxi basal fault arranged and evolved in synchronism with plate boundary fault-Jinshajiang-Ailao fault zone, with plate boundary fault aggravating, basal fault activity enhancing. It caused the Youjiang Basin evolved from continental rift basin to passive continental margin rift basin. According to tectonic activity intensity and basin filling feature, the Youjiang Basin evolution is divided into four phases:① from Lochkovian to Pragian,it was continental rift basin phase;② from Emsian to Eifelian, it was tensile developing phase;③ from Givetian to Frasnian,it was rift phase;④ until Famennian,it was tectonic dormancy phase; the latter 3 phases constitute passive continental margin rift basin phase. In each phase, tectonic sink and eustacy is different, so the sequence style is different, too. Isolated platform sequence was controlled mainly by relative sea-level and carbonate production, but basin among platforms was controlled mainly by tectonic, sea-level change, platform margin gravity current and sediment supply. According to above features, Devonian is divided into two Ⅱsequences and 18 Ⅲ sequences in the study area. At the same time, author builds the sequence-filling model of basin in different evolution phase. In short, the sequence filling difference is a response to basin tectonic evolution and global change of sea level.
出处
《地层学杂志》
CSCD
北大核心
2005年第1期62-70,共9页
Journal of Stratigraphy
基金
中石化重大科研项目"中国南方海相震旦系-中三叠统构造-层序岩相古地理研究及编图"成果之一
四川省重点学科"构造地质学"建设基金资助项目 (编号 :SZD0 40 8)
关键词
特提斯
右江盆地
广西
贵州
泥盆纪
盆地演化
层序
Tethys, Youjiang Basin, Devonian, tectonic evolution, sequence, Guangxi, Guizhou, Yunnan
