GEOL 103 Lecture Notes - Lecture 2: Stratigraphic Column, John Joly, Protolith
Document Summary
Absolute age: actual number of years since event, quantitative. John joly assumed the oceans started as freshwater, changed from transportation of sediments from rivers. Geologic column composite of sedimentary rocks formed overtime across the globe. 4. 56 ga1 based on correlation with meteorites and moon rocks (basalt) Hadean: hell (4. 56 - 3. 8 ga) differentiation of compositional layers of the earth formation of oceans, atmosphere, protocontinents oldest mineral, 4. 4 ga sedimentary protolith, zircon crystals oldest rock, 4. 28 ga igneous protolith, nuvvuagittuq greenstone life. Miller and urey experiment concocted a primitive atmosphere added lightning (energy) electric sparks included o2 produced amino acids building blocks of rna/dna. Mounded layers of bacteria remains fossilized as limestone prokaryotes sediment stuck to the mucus coating of the bacteria oldest are 3. 5 ga very common from 3. 2 - 1. 3 ga rare after 1. 3 ga photosynthesis changed that atmosphere. Co2 + h2o organic matter + o2 (free oxygen)
