秦岭晚古生代弧前增生的背驮型盆地体系  

Late Paleozoic forearc accretionary piggyback type basin system in the South Qinling,Central China

作　　者：王宗起[1] 王涛[1] 闫臻[1,2] 闫全人[1] 

机构地区：[1]中国地质科学院地质研究所 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《地质通报》2002年第8期456-464,共9页Geological Bulletin of China

基　　金：国家自然科学基金项目(49972074);地质调查项目(DKD2001002)资助。

摘　　要：秦岭发育了受断裂控制的晚古生代沉积盆地,其基底是具有洋壳、众多碳酸盐岩孤岛以及岛弧、弧前增生楔的洋盆底;盆地的主要边界逆冲断裂表现为背驮式的活动特征;各个盆地虽都有自己的沉积特点,但盆地的相对水深总体由北向南逐渐加大,反映出弧前大陆斜坡的古地理特征;盆地初始规模较大,到后期渐小,盆地充填呈退积序列,揭示了秦岭晚古生代盆地具有弧前增生的背驮型盆地性质。Late Paleozoic fault-controlled sedimentary basins are developed in the South Qinling.There have been disputes over their origin and evolution for a long time.Their basement is the bottom of an o-ceanic basin that is characterized by oceanic crust,many isolated carbonate reefs on volcanic rocks and is-land arcs and forearc accretionary wedges.The major boundary thrusts of the basins display the features of piggyback-type activity.Each basin has its own sedimentary characteristics,but the relative water depths of these oceanic basins generally increase progressively from north to south,reflecting the paleogeographic characteristics of the forearc slope.At the initial stage the basins were large and at the late stage they be-came small and were filled by the offlap sequence,revealing that the South Qinling Late Paleozoic basins have the nature of forearc accretionary piggyback-type basins.

关 键 词：秦岭 晚古生代 背驮型盆地 断裂控制 洋壳 弧前增生 

分 类 号：P544.4[天文地球—构造地质学]