01:460:100 Study Guide - Final Guide: Alleghanian Orogeny, Taconic Orogeny, Grenville Orogeny

• School: Rutgers University
• Department: Geological Sciences
• Course: 01:460:100
• Professor: C.Lepre

Document Summary

Relative age - age of something in relation to another. Numerical age - the absolute age, given in years. Geologic column - a composite stratigraphic column, that represents the entirety of earth history. Note: hadean eon is not shown because rocks did not preserve a record of it. Eons are split into eras, eras into periods, and periods in epochs. Simple bacteria and archaea appeared during the archean, but complex invertebrates without shells did not evolve until the late proterozoic. Appearance of invertebrates with shells defines the precambrian-cambrian boundary, in which there was a sudden diversification of life, called the. First fish in ordovician, spread of land plants during silurian, first amphibians during the devonian. Reptiles appeared during the pennsylvanian period, but dinosaurs didn"t appear till the triassic (mesozoic era was age of dinosaurs) Small mammals appeared during the triassic, but didn"t flourish until the beginning of the cenozoic era (age of mammals)