下盘的英文：
footwall

Let's have a game of chess.
咱们来下盘棋。

Will you care for a game of chess?
下盘象棋好吗?

A vertical fault has neither a footwall nor a hanging wall.
具有直立断层面的断层既无上盘，也无下盘。

If a fault has a vertical fault plane. How do we determine its hanging wall and footwall?
若一断层的断层面是直立的，我们怎么去确定它的上盘和下盘呢?

A vertical fault has neither a footwall nor a hanging wall.
具有直立断层面的断层既无上盘，也无下盘。

So the fault on the cliff is a reverse fault because the red rock layer in the hanging wall has moved up relative to that in the footwall.
这样看来，发育在悬崖上岩层中的那条断层就是一逆断层了，因为上盘的红色岩层相对于下盘的红色岩层发生了沿断层面向上位移的运动。

Then the block in the southern side of this fault is the hanging wall and the block in the northern side of this fault is the footwall.
那么，位于这条断层南侧的岩层是上盘，位于这条断层北侧的岩层则是下盘。

In structural geology the relative movement of the banging wait and footwall is a major factor to classify various faults.
在构造地质学中，断层上盘和下盘的相对位移运动特征是划分各种类型断层的一个主要因素。

If a fault has a vertical fault plane. How do we determine its hanging wall and footwall?
若一断层的断层面是直立的，我们怎么去确定它的上盘和下盘呢?