Finding the key bed in these situations may help determine whether the fault is a normal fault or a thrust fault.
Sixteen years after his discovery, he published a geological map of England showing the rocks of different geologic time eras.
Photo from Glen Canyon National Recreation Area, Utah.
Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age, (i.e. In geology, rock or superficial deposits, fossils and lithologies can be used to correlate one stratigraphic column with another.
Cross-cutting relations can be used to determine the relative ages of rock strata and other geological structures.
Explanations: A – folded rock strata cut by a thrust fault; B – large intrusion (cutting through A); C – erosional angular unconformity (cutting off A & B) on which rock strata were deposited; D – volcanic dyke (cutting through A, B & C); E – even younger rock strata (overlying C & D); F – normal fault (cutting through A, B, C & E).