Multichannel Seismic Study of Eastern Sunda Forearc, Indonesia

加积楔的后挡板必须发挥关键作用 在楔形发展的演变，但没有协议存在， 它们的意义或基本结构， 朝向或远离楔形物的趾部倾斜。 没有一个地区 足够好的图像来回答这个基本问题 令人满意。 我们提出了一个大的来源，多渠道的研究， 东巽他弧的弧前和弧后区， 在印度尼西亚，我们发现了逆冲断层的证据， 弧后的弧前和弧后冲断作用。 成像 逆冲断层（Sumba岛附近的Sawu逆冲断层）和逆止断层 几何将有重大影响：a）定义 弧前盆地地层与弧后盆地地层的构造合并 在逆冲推覆过程中的楔; B）识别最早的 楔体的增生产物， 俯冲吸积;以及c）确定相对时间 带内逆冲与弧后逆冲的关系 弧-陆碰撞 后者将需要一个计划， 钻井，多通道研究将提供一个框架， 这样的节目。 这些问题也将在一个 小的增生楔沿着弧后带发育 在这里我们可以完整地描绘出 止挡和楔形物下方的下板。 另外我们 拟开展8天数字单道地震 班达海内的剖面，使用1,000立方英寸的调谐 源数组。 目标是区域地震 1988年为钻探做准备。

Backstops of accretionary wedges must play a critical role in the evolution of wedge development, but no agreement exists as to their significance or fundamental structure, whether backstops dip toward or away from the toe of the wedge. No region is sufficiently well imaged to answer this fundamental question satisfactorily. We propose a large source, multichannel study of the forearc and backarc areas of the eastern Sunda arc, Indonesia, where we have found evidence of backthrusting in the forearc and backarc thrusting in the backarc. Imaging the backthrust (the Sawu thrust near Sumba Island) and backstop geometry will have significant implications for: a) defining the tectonic incorporation of forearc basin strata into the rear of the wedge during backthrusting; b) identifying the earliest accretionary products of the wedge, and thus initiation of subduction accretions; and c) determining relative timing relations between backthrusting and back arc thrusting in a zone of arc-continent collision. The latter will require a program of drilling, and the multichannel study will provide a framework for such a program. These questions will also be addressed in a small accretionary wedge developed along the zone of backarc thrusting, where we can completely image the structure of the backstop and lower plate beneath the wedge. In addition, we propose to carry out 8 days of digital single-channel seismic profiling within the Banda Sea, using a 1,000 cubic inch tuned source array. The objective will be regional seismic stratigraphy in preparation for drilling in l988.