Start Dating 2 relating

Dating 2 relating

Observation of modern marine and non-marine sediments in a wide variety of environments supports this generalization (although cross-bedding is inclined, the overall orientation of cross-bedded units is horizontal).

This principle allows sedimentary layers to be viewed as a form of vertical time line, a partial or complete record of the time elapsed from deposition of the lowest layer to deposition of the highest bed.

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).

The principle of cross-cutting relationships pertains to the formation of faults and the age of the sequences through which they cut.

There are a number of different types of intrusions, including stocks, laccoliths, batholiths, sills and dikes.

Cross-cutting relations can be used to determine the relative ages of rock strata and other geological structures.

A similar situation with igneous rocks occurs when xenoliths are found.

These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in the matrix.

Sixteen years after his discovery, he published a geological map of England showing the rocks of different geologic time eras.