Model Calculations

Calculation of the change in atmospheric oxygen with time is straightforward based on reactions (1.7), (1.8), (6.1), and (6.2):

where mass of oxygen in the atmosphere rate of burial of organic carbon in sediments rate of oxidative weathering of organic carbon plus rate of oxidation of reduced carbon-containing gases released via diagenesis, metamorphism, and volcanism rate of pyrite (plus organic) sulfur burial in sediments rate of oxidative weathering of pyrite (and organic) sulfur plus rate of oxidation of reduced sulfur-containing gases released via diagenesis, metamorphism, and volcanism.

The 15/8 term refers to the stoichiometery of reactions (6.1) and (6.2). This equation shows that calculation of O2 over time requires a knowledge of the various fluxes: Fbg, Fwg, Fbp, Fwp. These fluxes have been estimated basically by three approaches: (1) the "rock abundance" method, which involves quantifying the amounts of organic carbon and pyrite sulfur originally buried in Phanerozoic sedimentary rocks; (2) the isotope mass balance method, which consists of calculations based on the carbon and sulfur isotopic composition of the oceans, as recorded in sedimentary rocks; and (3) the a priori method, which is based on theoretical models for the burial and oxidation of carbon and sulfur.

Organic Gardening

Organic Gardening

Gardening is also a great way to provide healthy food for you and your loved ones. When you buy produce from the store, it just isnt the same as presenting a salad to your family that came exclusively from your garden worked by your own two hands.

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