GENERAL GEOLOGY

Detailed explanation-1: -If a set of rock layers has been disturbed, the youngest layer may no longer be on top. One way scientists determine the original order is to compare the disturbed rock layers with a similar but undisturbed stack of layers.

Detailed explanation-2: -The law of superposition states that rock strata (layers) farthest from the ground surface are the oldest (formed first) and rock strata (layers) closest to the ground surface are the youngest (formed most recently).

Detailed explanation-3: -The intrusion (D) cuts through the three sedimentary rock layers, so it must be younger than those layers. The principle of superposition states that the oldest sedimentary rock units are at the bottom, and the youngest are at the top. Based on this, layer C is oldest, followed by B and A.

Detailed explanation-4: -A syncline is a fold that bends downward, causing the youngest rocks are to be at the center and the oldest are on the outside.