Sector‐collapse structures ranging up to 27 km wide with up to 7.7 km bankward erosion (scalloped margins) and linear escarpments occur along the east‐north‐east‐trending, south‐facing margins of the Yangtze Platform and Great Bank of Guizhou. Exposure of one of the structures on the rotated limb of a syncline displays the geometry in profile view. Declivities range from 65° to 90° in the upper wall and decrease asymptotically to the toe. Catastrophic collapses of the margins in both platforms occurred during the late Ladinian as constrained by the ages of strata truncated along the margins and the siliciclastic turbidites that onlap collapse structures. Middle Triassic Anisian and Ladinian platform‐edge reef facies and platform‐interior facies were truncated along both the Yangtze and Great Bank of Guizhou margins. Lower Triassic facies were also truncated along the Great Bank of Guizhou margin. Gravity transport during the main episodes of collapse occurred as mud‐rich debris‐flows and as mud‐free hyper‐concentrated flows. Clasts, several to tens of metres and, exceptionally, hundreds of metres across, were transported to the basin. Following collapse, talus, carbonate turbidites and periplatform‐mud accumulated at the toe of slope. Shedding of skeletal grains and carbonate mud indicates active carbonate factories at the margin. Preserved sections of the margins demonstrate that the platforms evolved high‐relief, accretionary escarpments prior to collapse. High‐relief, without buttressing by basin‐filling sediments, predisposed the margins to collapse by development of tensile strain and fracturing within the margin due to the lack of confining stress. The linear geometry of margins and active tectonics in the region supports tectonic activity triggering the collapse. Collapse is thus interpreted to have been triggered by fault movement and seismic shock. Comparison with other systems indicates that evolution from high‐relief accretion to tectonic collapse of largely lithified margins resulted in large sector‐collapse structures and deposition of a coarse, generally mud‐poor breccia apron.

中文翻译：

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扬子平台和贵州大银行的巨型部门倒塌结构（扇形边缘）：碳酸盐台地边缘塌陷系统的成因意义

扬子台地和贵州大银行的东北东向，南向边缘出现了扇形塌陷结构，宽达27公里，向岸侵蚀达7.7公里（扇形边缘）和线性悬崖。向斜线的旋转分支上的结构之一暴露会在轮廓视图中显示几何形状。上壁的倾角范围从65°到90°，并逐渐减小到脚趾。两个平台的边缘都发生了灾难性的塌陷，这是在拉丁晚期发生的，这是由于沿边缘被截断的地层年龄和重叠塌陷结构上的硅质碎屑浊度所致。扬子和贵州大边缘的中三叠世Anisian和Ladinian台缘礁相和台内相相被截断。下三叠纪相也沿贵州大银行边缘被截断。在坍塌的主要时期，重力输送以泥浆丰富的泥石流和无泥浆的高浓度泥石流发生。几米到几十米，甚至超过数百米的碎石被运到盆地。坍塌后，距骨的脚趾处堆积了距骨，碳酸盐浊度和外围平台泥。骨骼颗粒和碳酸盐泥的脱落表明边缘有活跃的碳酸盐工厂。边缘的保留部分表明，平台在塌陷之前演化为高浮雕的增生悬崖。高起伏，没有盆地填充沉积物的支撑，由于缺乏约束应力，边缘容易因拉伸应变的发展和边缘内的破裂而塌陷。该区域边缘和活动构造的线性几何结构支持触发塌陷的构造活动。因此，崩溃被认为是由断层运动和地震冲击引起的。与其他系统的比较表明，从高浮雕增生到大部分岩性边缘的构造塌陷的演化导致了大​​型扇形塌陷结构和粗大的，通常是贫瘠的角砾岩围裙的沉积。