GLY 101 Study Guide - Midterm Guide: Principle Of Faunal Succession, Precambrian, Archean

60 views3 pages

Document Summary

Relative age dates: placing rocks and geologic events in their proper sequence. Numerical (absolute) dates: define the actual age of a particular geologic event. Principle of faunal succession: specific types of organisms lived during different time intervals. Principle of superposition: young rocks form on top of older ones. Structure of the geologic time scale: eon, era, period, epoch. Eras of the phanerozoic eon: cenozoic, mesozoic, paleozoic. Precambrian: proterozoic (youngest, archean, hadean (oldest) Preca(cid:373)bria(cid:374) spa(cid:374)s about 88% of earth s history. Layers of sediment are originally deposited horizontally. Geological feature that cuts across another feature, i. e. faults. A break in the rock record produced by erosion and/or non-deposition. Nonconformity: sedimentary rocks deposited above metamorphic or igneous rocks with time lost. Angular unconformity: tilted rocks overlain by flat-lying rocks. Disconformity: strata on either side of the unconformity are parallel. Ichnofossils: trace fossils of an organisms presence in the rocks but not the organism itself, i. e. footprints, trail marks, burrows, coprolites.