下切作用

本文提出微型构造是在砂体沉积的下切作用、砂泥岩差异压实及沉积古地形的影响下形成，与构造作用力无关。

This paper indicates that the mini-structure are the results of downcutting under deposition and differential compaction in sandstone-shale , and the effect of paleogeomorphic feature in sedimentation .

早期下切作用主要发生在新近纪时期，下切深度大于2000m，平均下切速率为770m/Ma；

It points out that the early incision stage occurred during the Neogene . In this period , the Minjiang upstream incised into a depth of at least 2000 m. The incision rate averaged 770 m / Ma .

强烈的下切作用为岸坡孕育小范围崩塌提供了必要的势能累积与临空面，另外，侧蚀作用进一步加剧了岸坡崩塌作用。

Cutting action under the strong small-scale collapse of the slope provides the necessary potential energy accumulation and free surface . In addition , the side etching effect exacerbates the slope collapse .