Exact stratigraphic correlation is today bothering the geologist more than any other subject relating to earth knowledge. This phase of geology has, indeed, been a constant source of embarrassment ever since the science's birth more than a century and a half ago. A hundred years ago William Smith, an English engineer, discovered the use of organic remains in the determination of the relative ages of rocks; and since his time fossils have been very generally depended upon in unravelling the geologic history of the various parts of the globe.
Proceedings of the Iowa Academy of Science
©1909 Iowa Academy of Science, Inc.
Keyes, Charles R.
"Orotaxial Geologic Correlation and Diastrophism,"
Proceedings of the Iowa Academy of Science, 16(1), 153-157.
Available at: https://scholarworks.uni.edu/pias/vol16/iss1/19