Ch. 5 Note: not covered –names of types of rock units, correlation Concepts: unconformities – disconformity, angular unconformity, nonconformity sedimentary facies marine transgression – regression – Walther’s law Review terms: angular unconformity, conformable, disconformity, fossil (in general), marine regression, marine transgression, nonconformity, principle of fossil succession, principle of inclusions, relative geologic time scale, sedimentary facies, unconformity, Walther’s law

Fossil preservation: environments favorable: rapid burial, mud, submarine fan (landslide), lake bottom; ice, amber (tree sap), tar, mummification body types: exoskeletons (i.e. clam), large bones Types: body fossils, trace fossils, molds, casts body fossils, whole body fossils, altered remains, unaltered remains (original material preserved) Table 5.1: alteration types: carbonization, replacement (pyrite on a shell), permineralization (petrified wood)

Marine transgressions: sea level rise. Facies migrate landward: offshore facies (limestone) moves over nearshore. nearshore facies (shale) moves over shoreline; shoreline facies (sandstone) is beneath the shale and limestone. Walther’s law: the facies observed in a conformable (undisturbed) vertical sequence will replace one another laterally. Marine regression: sea level drop. Facies migrate seaward: shoreline facies (sandstone) moves over nearshore (shale); nearshore facies moves over offshore facies (limestone).

Causes of changes in sea level: climate change (melting or freezing of Earth’s surface waters); underwater volcanism (increase or decrease in the rate of sea floor spreading); uplift or subsidence of continents