1. The Eras of Geologic Time
... to form crustal rifting, volcanic activity, mountain building, and sedimentation dominated the latter Precambrian period. Creatures resembling worms and jellyfish have been discovered but there is poor representation of life in this period. Precambrian rocks have yielded most of the world's gold and nickel in addition to copper, silver, radium and uranium. The major division of geologic time between five hundred and seventy million years ago to ... and are the subject of much research and controversy. During the interim between the late Precambrian and Paleozoic eras most of the evidenc...
- Word Count: 1841
- Approx Pages: 7
- Grade Level: Undergraduate