principle of historical geology

What does principle of uniformitarianism mean?

The present is key to the past. Geological process that shaped the earth today such as erosion and volcanism has occurred before in the past in similar ways

Principle of super position

It states that in an undeformed sequence of sefimentary rocks, the older layers are at the bottom while the younger layers are on the top

Principle of original horizontality

Layers of sedimentary rock are originally deposited horizontality, if you see any tilted or folded layer they were moved after deposition

Principle of cross cutting

If a fault or fold that cut across a rock layer, it must be younger than the rock that cuts it

Principle of inclusion

Any rock fragments found inside another rock must be older than the rock that contains it