Crust evolution

Ronov, A. B. (1964). Common tendancies in the chemical evolution of the Earth s crust, ocean, and atmosphere, Geochem. 8,715-743. 

Colorless, reactive gas. Oxygen was not present in the initial atmosphere of the Earth, although at 50 % it is the most common element in the crust of the Earth (oxides, silicates, carbonates, etc.). The compound with hydrogen is remarkable. The hydrides of all other elements are unpleasant compounds, but H20 is the molecule of life. The 02 found in the air today, of which it makes up 20 %, was formed in the process of evolution by photosynthesis of algae, which then also allowed life on solid land. Oxidation with oxygen became and is still the dominant pathway of life forms for obtaining energy (respiration). Used in medicine in critical situations. Oxidations play a key role in chemistry (sulfuric acid, nitric acid, acetic acid, ethylene oxide, etc.). The ozone layer in space protects the Earth from cosmic UV radiation. Ozone (03) is used in the... 

The outer crust of earth has provided the solid foundation for the evolution of human beings, who are the prime focus of interest and concern to archaeology. The main components of this crust are minerals and rocks, some consolidated and others occurring as sediments, nonconsolidated deposits, created by weathering processes from the minerals and rocks. All these minerals, rocks, and sediments, as well as everything else in the universe, are made up from just over 100 chemical elements listed in Appendix I. Most of the elements in the crust of the earth occur in extremely low relative amounts, and only a few, listed in Table 1, make up almost 99% of its total bulk (Bloom 1969). 

Taylor S.R., McLennan S.M. The continental crust Its composition and evolution, Oxford Blackwell, 1985. 

Let us first introduce some important definitions with the help of some simple mathematical concepts. Critical aspects of the evolution of a geological system, e.g., the mantle, the ocean, the Phanerozoic clastic sediments,..., can often be adequately described with a limited set of geochemical variables. These variables, which are typically concentrations, concentration ratios and isotope compositions, evolve in response to change in some parameters, such as the volume of continental crust or the release of carbon dioxide in the atmosphere. We assume that one such variable, which we label/ is a function of time and other geochemical parameters. The rate of change in / per unit time can be written... 

Albarede, F. Brouxel, M. (1987). The Sm/Nd secular evolution of the continental crust and depleted mantle. Earth Planet. Sci. Letters, 82, 25-35. 

Candela, P. A. (1986). Generalized mathematical models for the fractional evolution of vapor from magmas in terrestrial planetary crusts. In Chemistry and Physics of Terrestrial Planets, ed. E. K. Saxena, pp. 362-96. NY Springer. 

Bouman C, Elliott TR (1999) Li isotope compositions of Mariana arc lavas Implications for crust-mantle recycling. Ninth Goldschmidt Conf Abst, LPI Contribution 971, Lunar Planetary Institute, 35 Bouman C, Elliott TR, Vroon PZ, Pearson DG (2000) Li isotope evolution of the mantle from analyses of mantle xenoliths. J Conf Abst 5 239... 

Grustal reservoirs are also variable in Gl-isotope compositions (Figs. 1-6) due to fractionation of the Gl-isotope compositions inherited from their mantle source through fluid-mineral reactions, incorporation of G1 derived from the oceans and fractionation within fluid reservoirs by diffusion (see below). For example, the oceanic crust is enriched in Gl (and pore fluids depleted in Gl) through reaction of seawater with basaltic crust derived from the depleted mantle (Fig. 1 Magenheim et al. 1995). Undoubtedly, future investigations of Gl-isotopes in whole rocks and mineral separates will address the Gl-isotope compositions of these reservoirs and their evolution. 

Stevenson R, Upton BGJ, Steenfelt A (1997) Crust-Mantle interaction in the evolution of the Ilimaussaq Complex, South Greenland Nd isotopic studies. Lithos 40 189-202 Stewart MA, Boudreau AE, Spivack AJ (1996) Cl isotopes of the Stillwater Complex, Montana, and the formation of high-Cl Bushveld and Stillwater parent liquids during mantle metasomatism by Cl-rich fluids. Eos Trans, AGU 77 F829... 

Coleman ML (1971) Potassium-calcium dates from pegmatitic micas. Earth Planet Sci Lett 12 399-405 Condie KC (1993) Chemical composition and evolution of the upper continental crust contrasting results from surface samples and shales. Chem Geol 104 1-37... 

Richter FM, Davis AM, Ehel DS, Hashimoto A (2002) Elemental and isotopic fractionation of Type B calcium-, aluminum-rich inclusions Experiments, theoretical considerations, and constraints on their thermal evolution. Geochim Cosmochim Acta 66 521-540 Richter FM, Davis AM, DePaolo DJ, Watson EB (2003) Isotope fractionation by chemical diffusion between molten basalt and rhyolite. Geochim Cosmochim Acta 67 3905-3923 Rudnick RL, Fountain DM (1995) Nature and composition of the continental crust—a lower crustal perspective. Rev Geophys 33 267-309... 

Taylor SR, Mclennan SM (1995) The geochemical evolution of the continental crust. Rev Geophys 33 241-265... 

Taylor SR, McLennan SM (1985) The Continental Crust Its Composition and Evolution. Blackwell, Boston Tuit CB, Ravizza G (2003) The marine distribution of molybdenum. Geochim Cosmochim Acta 67 A4950 Tumlund JR, Keyes WR, Peiffer GL (1993) Isotope ratios of molybdenum determined by thermal ionization mass spectrometry for stable isotope studies of molybdenum metabolism in humans. Anal Chem 65 1717-1722... 

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