Relationships between Formative Processes of Notches and Tafoni Developing on Steep Slopes of Volcanic Breccia and Occurrences of Rock Falls: A Case at Mt. Gokenzan, Takamatsu City, Kagawa Prefecture, Japan: ─香川県高松市五剣山の例─
Relationships between Formative Processes of Notches and Tafoni Developing on Steep Slopes of Volcanic Breccia and Occurrences of Rock Falls: A Case at Mt. Gokenzan, Takamatsu City, Kagawa Prefecture, Japan: ─香川県高松市五剣山の例─
复制标题
火山角砾岩陡坡上的刻痕和塔福尼的形成过程与岩崩发生的关系：以日本香川县高松市五剑山为例：─以香川县高松市五剑山为例─
DOI：
10.5026/jgeography.126.425
复制
发表时间：
2017
影响因子：
3.1
通讯作者：
Daisuke Kanbara
中科院分区：
文献类型：
--
作者：
K. Nishiyama;S. Yokota;S. Hasegawa;Daisuke Kanbara
描述了日本四国香川中新世濑户内火山岩火山角砾岩悬崖上发育的切迹和塔福尼的形态特征。岩石表面的含水量在凹顶部分显示最高值。槽口壁上存在盐（如石膏），表明这些槽口是在高湿度下由盐风化形成的。在陡峭的悬崖上，形成了凹口和塔福尼，形成了一个遮阳板，这种不稳定的块体偶尔会随着罗克瀑布的坠落而坍塌。除了槽口和tafoni的发展，火山角砾岩内的裂缝也会导致罗克瀑布。因此，由于盐风化和张裂缝的间距，缺口加深的速率可能控制着这些悬崖上罗克瀑布的频率。
Morphological features of notches and tafoni, which are well developed on volcanic breccia cliffs of Miocene Setouchi volcanic rocks in Kagawa, Shikoku, Japan, are described. The moisture content of a rock surface shows the highest value at the concave roof portion. The presence of a salt, such as gypsum, on notch walls suggests these notches are formed by salt weathering under a high humidity. Notches and tafoni develop to produce a visor overhang on a steep cliff, and such unstable blocks occasionally collapse as rock falls. In addition to the development of notches and tafoni, cracks within volcanic breccia can also cause rock falls. Consequently, the rate at which notches deepen due to salt weathering and the spacing of tension cracks may control the frequency of rock falls from these cliffs.