冲积扇的地震反射特征及沉积模式

在我国东部地区的许多断陷湖盆内,普遍发育水下冲积扇。这些冲积扇沿湖盆的陡坡分布,它们在地震剖面上具有独特的反射波特征。根据外形,可分为陡崖楔状反射、陡崖串珠状反射、平行陡崖空白反射及陡崖丘状反射等四种类型。每种反射类型和一定形态的扇体相对应。根据扇体在地震剖面上的几何形态并结合其它资料,可以分析冲积扇的油气圈闭类型和含油性。

Reflection configurations and deposition of alluvial fans

There are a number of underwater fans in faultdepressed lake basins in eastern China. The alluvial fans spread over the steep slopes of those basins. The corresponding seismic reflections are cataloged by their configurations into four types, i.e., cliff-produced wedge reflections, ball chain reflections, mounded reflections and "dead spots" which are parallel to the cliff. Each type of reflection configuration corresponds to a special form of a fan. Combined with other information, the appearance of the fans on seismic sections may be used to analyse formations and oil potential of alluvial fans.