The principle of original horizontality is based on the fact that:
A) sediment usually accumulates in horizontal layers.
B) sedimentary rocks generally become younger from bottom to top.
C) sedimentary rocks must be older than an intruding dike.
D) rocks can be dated by studying radioactive decay of the elements.

Question

Quizplus · Accepted Answer

The principle of original horizontality states that sedimentary rocks are usually deposited in horizontal layers due to the effects of gravity. This principle is based on observation and can help geologists interpret the relative ages of rocks in a sequence.

The Principle of Original Horizontality Is Based on the Fact