1. The Eras of Geologic Time
... geologic time periods: Triassic, Jurassic, and Cretaceous. The term, meaning middle life, was introduced in 1841 by the English geologist John Phillips. In most places the rock layers deposited during the three eras are separated from one another by unconformities, breaks in the sequence of deposition of the geologic record. The Appalachian Mountains replaced the downward thrust of the earth's crust, while the eastern part of the Appalachian Mountains was deposited along ... North Africa began to rift apart. By later Mesozoic, tectonic activity increased dramatically, the new Indian Oce...
- Word Count: 1841
- Approx Pages: 7
- Grade Level: Undergraduate