BIOL 1510 Chapter Notes - Chapter 3: Cubic Zirconia, Igneous Rock, Issf 10 Meter Air Rifle
Document Summary
Igneous - rocks are formed from cooling of lava; no fossils - destroyed by heat of lava. Metamorphic - rocks are formed from igneous or sedimentary rock buried deep into the earth(by a fault) and changed by extreme heat and pressure; no fossils - sedimentary rock fossils destroyed by heat. Sedimentary - rocks formed by deposition of sand and fine particles of debris, often visible as fossils in layered rock. Stratigraphy - form of ordering geological sedimentary rock formations, relative dating. Newer layers on top of older layers. Crustal movements & uplift cause soil to tilt & fold. Erosion causes loss of layers & unconformities - gaps in the fossil record. Radiometric dating - various radioisotope decay methods used to estimate absolute dates of geological events creating fossilized layers. 40+ methods, each with another radioactive element. (p126ar) potassium-40 (k-40) decays to argon (ar-40): half-life = 1. 26 billion years; used to date formation of igneous rocks.
