GEOL 1020 Lecture Notes - Lecture 17: Methanogenesis, Methane Clathrate, Archaea

• School: CU-Boulder
• Department: Geological Sciences
• Course: GEOL 1020
• Professor: Jaelyn Eberle

Document Summary

For the exam, know the eras, geologic periods (cambrian through quaternary), and the. If we knock out respiration (by decomposers) in the swamp, a high rate of burial means less o2 is being used up by decomposition, so atmospheric o2 increases. Co2 on the other hand, gets locked up in an underground reservoir (coal beds. ) Co2 decreases in atmosphere and o2 increases in atmosphere. Co2 in the atmosphere gets depleted in 12c (and higher in 13c) Weathering: the physical and chemical processes that break down rocks. Most limestone gets subducted and releases co2 back to the atmosphere. If burial rate of organic carbon = weather rate (which returns carbon to the atmosphere), then burial of carbon does not alter the 13c/12c in atmosphere. 13c/12c measured in limestones or forams does not change. Lighter 12c is not all returned to the atmosphere, so the atmosphere gets depleted in 12c, and the heavier isotope 13c is left = higher 13c/12c ratio.