Age
Geologists employ biostratigraphy, the use of index fossils, for dating sedimentary rock units like the Coon Creek. Index fossils are species of plants or animals that existed over a wide area for a geologically short period of time (Russell and Parks 1975). The cephalopod Jeletzkytes nodosus is a time-sensitive fossil found in rocks a little younger than 70.6 million years old in the western United States. Other index fossils from Coon Creek date a little older than 70.6 million years. The overlap indicates that Coon Creek sediments were probably deposited between 70 and 71 million years ago.
Read more about this topic: Coon Creek Formation
Famous quotes containing the word age:
“The time passes so quickly during these full and active middle years that most people arrive at the end of middle age and the beginning of later maturity with surprise and a sense of having finished the journey while they were still preparing to commence it.”
—Robert Havighurst (20th century)
“He has the earnestness of a prophet. In an age of pedantry and dilettantism, he has no grain of these in his composition. There is nowhere else, surely, in recent readable English, or other books, such direct and effectual teaching, reproving, encouraging, stimulating, earnestly, vehemently, almost like Mahomet, like Luther.... His writings are a gospel to the young of this generation; they will hear his manly, brotherly speech with responsive joy, and press forward to older or newer gospels.”
—Henry David Thoreau (1817–1862)
“As the age of television progresses the Reagans will be the rule, not the exception. To be perfect for television is all a President has to be these days.”
—Gore Vidal (b. 1925)