Exam 17: Geologic Time: Concepts and Principles

Denver 280 million years ago was covered by glaciers.

How are zones of rocks that are deposited during equivalent time intervals constructed using fossil assemblages?

What criteria are used to correlate rock units in different areas?

Different varieties of an atom that have a different number of neutrons in their nuclei are ____________________.

The most accurate radiometric dates are obtained from ____________________ rocks.Only in very unusual circumstances can ____________________ rocks be radiometrically dated.

What kind of rocks (igneous,sedimentary,metamorphic)have been most important in determining absolute age dates for the geologic time scale? Explain why.

What is the goal of subsurface correlation techniques that is used in the search for oil and gas?