17
Stone writing
Humans write words on paper, while stones write words on the earth.
0 The earth is paper, the stone is written as a big S
Stone is written as a small S
Take a mountain and write a letter Z
stone letter W
s0stone letter W
s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0s0 N
letters written in stone V
letters written in stone N
2 continents converge, collide and squeeze, causing the rock to form folds, and the folds are divided into many levels: first-level, second-level, third-level... The large folds are covered with small folds, and the small folds are covered with smaller folds... In different parts of the large folds, the small folds (also known as parasitic folds) have different shapes. "M"-shaped folds appear on the top of the anticline folds, "W"-shaped folds appear on the bottom of the slanted folds, and "Z"-shaped folds appear on the left and right wings. This is the famous Pumpelly criterion in tectonic geology.
Pumpelly's Rule diagram
(yellow layer indicates weak rock layer, forming parasitic folds)
parasitic folds generally appear in weak component layers. According to the location of the parasitic folds, the tectonic geology community determines the existence of large folds in the local area. Finding folds is an important task in oil exploration, as oil almost always appears on the top of anticline folds.
