Tulane Physical Geology Laboratory -INSTRUCTOR: E. GONZALEZ

Last Updated September 14, 2003

GEOLOGIC TIME -OUTLINE

LABORATORY EIGHT –Dating of Rocks, Fossils and Geologic Events

Laboratory Manual in Physical Geology by The American Geological Institute (AGI) and the National Association of Geoscience Teachers (NAGT); Richard M. Busch, Editor; 6th Edition, 2003.

GEOLOGIC RECORD

Sequence

Colors, textures, chemical composition and fossils = FORMATION

Correlations

GEOLOGIC TIME (RELATIVE and ABSOLUTE)

GEOLOGIC TIME SCALE (p. xiv and Figure 8.13, p. 136)

ROCK UNITS AND CORRESPONDING GEOLOGIC TIME UNITS (p. 129)

-RELATIVE GEOLOGIC AGE

FORMATION Member Strata

BASIC LAWS or PRINCIPLES

ORIGINAL HORIZONTALITY

LATERAL CONTINUITY

SUPERPOSITION

OF INCLUSION

OF CROSS-CUTTING

OF UNCOFORMITIES

DISCONFORMITY

ANGULAR UNCONFORMITY

NONCONFORMITY

USE OF FOSSILS

PRINCIPLE OF FOSSIL SUCCESSION

Range Zone

Index Fossils

Brachiopods, Trilobites, Reptiles, Mammals, Amphibians, Sharks.

-ABSOLUTE AGE

RADIOMETRIC DATING

ISOTOPES (Parent – Daughter isotopes = DECAY PAIR)

HALF LIFE (Rate of Decay) ---Exponential (Figure 8.16, p. 138)