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Continents, carbonates

Diamond pipes exhume samples of ancient rocks from 200 km depth beneath continents. Carbon and nitrogen isotopic anomalies in the diamonds and sulfur isotope anomalies within diamond inclusions provide evidence for ancient subduction and the existence of an ancient active surface biochemical cycle. Farquhar et al. [58] present data on 2.9 billion-year-old diamonds and a brief review of the literature on the topic. Given the rarity of diamond pipes, these data relate to the existence of processes and give little information on fluxes into the mantle. [Pg.67]

The terrestrial component of the dust particles embedded in the ice consists of volcanic ash, finegrained dust derived from soil on the continents, carbon particles released by forest fires, biogenic particles (e.g., the skeletons of diatoms, seeds, and pollen grains), aerosol particles of atmospheric origin, including sea-spray particles that nucleate snow flakes (Section 17.10). In addition, the uppermost layer of snow and fim that was deposited after the start of the Industrial Revolution (i.e., post ad 1850) contains anthropogenic detritus such as flakes of metal, paint, and plastics, fly-ash particles and other combustion products, fibers (composed of wood, cotton, and synthetics), industrial contaminants (e.g., lead), and radioactive nuchdes released by the testing of nuclear weapons and by the operation of nuclear reactors (Faure et al. 1997). [Pg.672]

Owing to the stability of the uranyl carbonate complex, uranium is universally present in seawater at an average concentration of ca. 3.2/rgL with a daughter/parent activity ratio U) of 1.14. " In particulate matter and bottom sediments that are roughly 1 x 10 " years old, the ratio should approach unity (secular equilibrium). The principal source of dissolved uranium to the ocean is from physicochemical weathering on the continents and subsequent transport by rivers. Potentially significant oceanic U sinks include anoxic basins, organic rich sediments, phosphorites and oceanic basalts, metalliferous sediments, carbonate sediments, and saltwater marshes. " ... [Pg.43]

The absorption occurs as a result of the driving force of the partial pres-Miie from the gas to the liquid. The reactions involved are reversible bv changing the system temperature or pressure, or both. Therefore, die at[ueous base solution can be regenerated and thus circulated in a contin nous cycle. The majority of chemical solvent processes use either an amine or carbonate solution. [Pg.162]

Sodium, 22 700 ppm (2.27%) is the seventh most abundant element in crustal rocks and the fifth most abundant metal, after Al, Fe, Ca and Mg. Potassium (18 400 ppm) is the next most abundant element after sodium. Vast deposits of both Na and K salts occur in relatively pure form on all continents as a result of evaporation of ancient seas, and this process still continues today in the Great Salt Lake (Utah), the Dead Sea and elsewhere. Sodium occurs as rock-salt (NaCl) and as the carbonate (trona), nitrate (saltpetre), sulfate (mirabilite), borate (borax, kemite), etc. Potassium occurs principally as the simple chloride (sylvite), as the double chloride KCl.MgCl2.6H2O (camallite) and the anhydrous sulfate K2Mg2(S04)3 (langbeinite). There are also unlimited supplies of NaCl in natural brines and oceanic waters ( 30kgm ). Thus, it has been calculated that rock-salt equivalent to the NaCl in the oceans of the world would occupy... [Pg.69]

Figure 1. Changes in global climate due to increased atmospheric CO2 will alter carbon cycle processes in land, continent margins, and oceans, which will in turn effect the atmospheric C02concentration. Processes that may have effects large enough to Eilter future projections of atmospheric CO2 are listed under their geographic region. Figure 1. Changes in global climate due to increased atmospheric CO2 will alter carbon cycle processes in land, continent margins, and oceans, which will in turn effect the atmospheric C02concentration. Processes that may have effects large enough to Eilter future projections of atmospheric CO2 are listed under their geographic region.
The most widely used form of the carbonaceous fuels is perhaps the solid fuel, coal. Though occurring basically in the solid form, coal can be converted to both liquid and gaseous forms. In the solid form, coal is basically of two types charcoal (prepared by carbonization of wood) and mineral coal (obtained from coal mines). Coal is found on every continent,... [Pg.90]

Table 1. Carbon footprint of continents and most important nations [3]... Table 1. Carbon footprint of continents and most important nations [3]...
The planets nearest the Sun have a high-temperature surface while those further away have a low temperature. The temperature depends on the closeness to the Sun, but it also depends on the chemical composition and zone structures of the individual planets and their sizes. In this respect Earth is a somewhat peculiar planet, we do not know whether it is unique or not in that its core has remained very hot, mainly due to gravitic compression and radioactive decay of some unstable isotopes, and loss of core heat has been restricted by a poorly conducting mainly oxide mantle. This heat still contributes very considerably to the overall temperature of the Earth s surface. The hot core, some of it solid, is composed of metals, mainly iron, while the mantle is largely of molten oxidic rocks until the thin surface of solid rocks of many different compositions, such as silicates, sulfides and carbonates, occurs. This is usually called the crust, below the oceans, and forms the continents of today. Water and the atmosphere are reached in further outward succession. We shall describe the relevant chemistry in more detail later here, we are concerned first with the temperature gradient from the interior to the surface (Figure 1.2). The Earth s surface, i.e. the crust, the sea and the atmosphere, is of... [Pg.4]

I use the seasonal simulation to explore the sensitivity of this energy balance climate model to such features of the climate system as permanent ice and snow at high latitudes, seasonal ice and snow, cloud cover, carbon dioxide amount, and the distribution of the continents. [Pg.99]

Kuhn, W. R., J. C. G. Walker, and H. G. Marshall. 1989. The effect on Earth s surface temperature from variations in rotation rate, continent formation, solar luminosity, and carbon dioxide. J. Geophys. Res. 94, 11129-36. [Pg.181]

An emulsion of the oil and propylene carbonate (imiscible with the oils) is pumped through the cell with a carbon-felt cathode. The polychlorinated biphenyls are continously extracted into the electrolysis medium. 30-50% current efficiencies for the decrease in the polychlorinated biphenyl concentrations from 700 to less than 1 ppm are possible. [Pg.212]

Away from the influence of the continents, the %CaC03 in the sediments is largely controlled by the processes that determine whether sinking detrital calcium carbonate survives the trip to the seafloor. Some of these processes are related to the thermodynamic controls on calciiun carbonate solubility and others are a consequence of the relative rates of particle sinking and dissolution. [Pg.394]

Cadle, S.H. Groblicki, J.P. Stroup, D.P. "An automated carbon analyzer for particulate samples", presented at the Second Chemical Congress of the North American Continent, Las Vegas, Nevada., August 1980. [Pg.232]


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See also in sourсe #XX -- [ Pg.233 , Pg.234 , Pg.235 ]




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