Lithosphere/rocks carbon

E. L. Shock (1990) provides a different interpretation of these results he criticizes that the redox state of the reaction mixture was not checked in the Miller/Bada experiments. Shock also states that simple thermodynamic calculations show that the Miller/Bada theory does not stand up. To use terms like instability and decomposition is not correct when chemical compounds (here amino acids) are present in aqueous solution under extreme conditions and are aiming at a metastable equilibrium. Shock considers that oxidized and metastable carbon and nitrogen compounds are of greater importance in hydrothermal systems than are reduced compounds. In the interior of the Earth, CO2 and N2 are in stable redox equilibrium with substances such as amino acids and carboxylic acids, while reduced compounds such as CH4 and NH3 are not. The explanation lies in the oxidation state of the lithosphere. Shock considers the two mineral systems FMQ and PPM discussed above as particularly important for the system seawater/basalt rock. The FMQ system acts as a buffer in the oceanic crust. At depths of around 1.3 km, the PPM system probably becomes active, i.e., N2 and CO2 are the dominant species in stable equilibrium conditions at temperatures above 548 K. When the temperature of hydrothermal solutions falls (below about 548 K), they probably pass through a stability field in which CH4 and NII3 predominate. If kinetic factors block the achievement of equilibrium, metastable compounds such as alkanes, carboxylic acids, alkyl benzenes and amino acids are formed between 423 and 293 K. 

Zinc is the 24th most abundant element in the earth s crust. The Zn concentration in the lithosphere is 50-70 mg/kg (Vinogradoc, 1959 Adriano, 2001). Basic igneous rocks contain higher Zn (70-130 mg/kg) than metamorphic and sedimentary rocks (80 mg/kg). Carbonate and limestones contain low Zn (16-20 mg/kg) (Aubert and Pinta, 1977). The total Zn concentration in the soils of the world ranges from 10 to 300 mg/kg (Swaine, 1955), with average concentrations from 50 to 100 mg/kg (Aubert and Pinta, 1977). Arid and semi-arid soils vary from trace levels (subdesert soils) to 900 mg/kg (saline alkali soils) (Aubert and Pinta, 1977). The average Zn concentration in the arid and semi-arid soils of the U.S. (62.9 mg/kg) is... 

From available, though approximate, estimates, about 1023 g of carbon-containing gases are concentrated in the rocks of the Earth s crust and mantle (lithosphere) (Korstenshtein, 1984 Sokolov, 1971). This mass of carbon exceeds by approximately 104 times the amount present today in the biosphere (over the Earth surface). Between the biosphere and lithosphere there is a constant, very intensive exchange of carbon that is self-regulatory. From the data of Barenbaum (2000, 2002), due to the Le Chatelier principle (Krapivin et al., 1982), the content of mobile carbon in the system tries to attain a stable relationship ... 

The lithosphere consists primarily of rocks and minerals. Some of the important classes of metal compounds found in the lithosphere are oxides, sulfides, silicates, phosphates, and carbonates. The atmosphere surrounding the earth contains oxygen, so several metals such as iron, aluminum, tin, magnesium, and chromium are found in nature as the oxides. Sulfur is found in many places in the earth s crust (particularly in regions where there is volcanic activity), so some metals are found combined with sulfur as metal sulfides. Metals found as sulfides include copper, silver, nickel, mercury, zinc, and lead. A few metals, especially sodium, potassium, and magnesium, are found as the chlorides. Several carbonates and phosphates occur in the lithosphere, and calcium carbonate and calcium phosphate are particularly important minerals. 

Oxygen is by far the most abundant element in cmstal rocks, composing 46.6% of the lithosphere (4). In rock mineral stmctures, the predominant anion is 0, and water (H2O) itself is almost 90% oxygen by weight. The nonmetaUic elements fluorine, sulfur, carbon, nitrogen, chlorine, and phosphoms are present in lesser amounts in the lithosphere. These elements aU play essential roles in hfe processes of plants and animals, and except for phosphoms and fluorine, they commonly occur in earth surface environments in gaseous form or as dissolved anions. 

Carbon. Most of the Earth s supply of carbon is stored in carbonate rocks in the Hthosphere. Normally the circulation rate for lithospheric carbon is slow compared with that of carbon between the atmosphere and biosphere. The carbon cycle has received much attention in recent years as a result of research into the possible relation between increased atmospheric carbon dioxide concentration, most of which is produced by combustion of fossil fuel, and the "greenhouse effect," or global warming. Extensive research has been done on the rate at which carbon dioxide might be converted to cellulose and other photosyntheticaHy produced organic compounds by various forms of natural and cultivated plants. Estimates also have been made of the rate at which carbon dioxide is released to soil under optimum conditions by various kinds of plant cover, such as temperature-zone deciduous forests, cultivated farm crops, prairie grassland, and desert vegetation. 

Calcium (3.4% of lithosphere) occurs as carbonate in the minerals aragonite and calcite and the rocks limestone, chalk and marble, and as sulphate in anhydrite, CaS04, and gypsum, CaS04.2H20. All are plentiful and widely distributed. The metal, which has both h.c.p. and c.c.p. forms, is made (Fig. 138) by electrolysing the fused chloride, CaClg, a by-product of the Solvay process. 

Carbon occurs in the atmosphere predominantly as gaseous COj, and in the lithosphere as rocks, mostly CaCOs and fossil organic carbon. The atmospheric and lithospheric carbon pools are linked by the hydrospheric carbonate buffer system ... 

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