天然ダムの構成

先日の引用文献の Fanさん、地質の方でしょうか。天然ダムの構成に関する話題も報告されていました。

Fan et al. (2017.) Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake.

Sub-type III: landslide dams with partly intact rock strata at the base topped by large boulders and blocks or soil with rock fragments, showing a two-layered (e.g. the Xiaojiaqiao dam) or three layered (the Tangjiashan dam, Fan et al. 2012b) internal structure. Such dams are mainly formed by deep-seated rock slides or avalanches that fail as a largely intact mass and run into relatively narrow valleys. Due to the topographic constraints on the landslide movement, the sliding rock mass cannot be disintegrated completely, part of which still keeps the original geological
structure.