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"2.01 Overview - Mineral Physics: Past, Present, and Future G. D. Price, University College London, London, UK 2007 Elsevier B.V. All rights reserved. Mineral physics involves the application of physics and chemistry techniques to understand and predict the fundamental behavior of Earth materials (e.g., Kieffer and Navrotsky, 1985), hence providing solutions to large-scale problems in Earth and planetary sciences. Mineral physics is relevant to mineral properties (Ks, adiabatic bulk modulus and density) via: \[ \frac{d}{dr} \left( r^4 \frac{dP_s}{dr} \right) = 0 \] where \( P_s \) is the seismic parameter as a function of radius. This parameter is given by: \[ j_r = \frac{1}{4} V_2 p_r - \frac{4}{3} V_2 s_r \] and \[ K_s r = \frac{1}{4} V_2 p_r - \frac{4}{3} V_2 s_r \] These properties are relevant to all aspects of solid Earth sciences, from surface processes and environmental geochemistry to the deep Earth and the nature of the core. In this volume, we focus only on the geophysical applications of mineral physics (see also Ahrens (1995), Hemley (1998), and Poirier (2000)). These applications are not just constrained to understanding the structure of the Earth (see Volume 1) and its evolution (see Volume 9), but will play a vital role in our understanding of the dynamics and evolution of other planets in our solar system (see Volume 10 and Oganov et al. (2005)). Mineral physics as such has only been recognized for some 30 years, but its origins can be traced back to the foundations of solid Earth geophysics itself. For example, Oldham's (1906) and Gutenberg's (1913) work on seismological characteristics of the core led to the inference that the outer core is liquid because it cannot support shear waves. A landmark paper in the history of mineral physics applied to solid Earth understanding is "Density of the Earth" by Williamson and Adams (1923). Here, elastic constants of various rock types were used to interpret density profiles as functions of depth inferred from seismic and gravitational data. Further progress in inferring the nature of Earth's deep interior rested upon experimental determination of elastic properties of rocks and minerals as a function of pressure and temperature. Notably, this work was pioneered over several decades by Bridgman (1958). In parallel with these experiments, Murnaghan (1937) and Birch (1938) developed greater understanding of the theory behind the effect of pressure on compressibility. These insights enabled Birch (1952) to write his classic paper "Elasticity and the Constitution of the Earth's Interior," laying foundations for current understanding of our planet’s composition and structure. One notable outcome from studying pressure and temperature effects was the discovery of new high-density polymorphs of crustal minerals. Thus, Coes (1953) synthesized a new high-density polymorph of SiO2 (subsequently named coesite), and Ringwood (1959) reported the synthesis of spinel-structured Fe2SiO4 (predicted by Bernal (1936)). Ringwood and colleagues went on to make other high-density silicate polymorphs, including phases now thought to make up the transition zone of the mantle: spinelloids wadsleyite (-Mg2SiO4) and ringwoodite (-Mg2SiO4), and garnet-structured MgSiO3 (majorite). Further insights into deep Earth minerals came from Stishov and Popova (1961), who synthesized the rutile-structured polymorph of SiO2 (stishovite) with Si in 1/2 octahedral coordination, and Takahashi and Bassett (1964), who first made the hexagonal close-packed polymorph of Fe, today thought to be found in Earth's core. As high-pressure and -temperature experimental techniques evolved, further phases were discovered, notably the postspinel perovskite-structured MgSiO3 (Liu, 1975). This discovery and subsequent work on silicate mineral phase diagrams enabled a robust model for mantle composition. However, recent discoveries of the postperovskite phase (Murakami et al., 2004; Oganov and Ono, 2000) have added uncertainty to the nature of the D0 zone and core-mantle boundary. The current view of mantle mineralogy is summarized in Figure 2. The core is considered composed of iron (with minor amounts of nickel) alloyed with light elements (probably O, S, or Si). The solid inner core crystallizes from the outer core, containing less light elements. Chapters 2.02, 2.03, 2.04, and 2.05 review our understanding of mantle mineralogy and core composition. Upper mantle Lower mantle D layer Core Pressure (GPa) CMB 70 136 Cpx + Opx Ca-perovskite (cubic or tetragonal) CaIrO3-type phase Garnet Fe- and Al-bearing Mg-perovskite Liquid Fe Olivine Ringwoodite Wadsleyite 410 660 Ferropericlase (high spin) (low spin) 2000 Depth (km) 2700 2900 Figure 2 Phase relations of pyrolitic mantle composition as a function of depth. From Ono S and Oganov AR (2005) In situ observations of phase transition between perovskite and CaIrO3-type phase in MgSiO3 and pyrolitic mantle composition. Earth and Planetary Science Letters 236: 914-932. Mineral Physics: Past, Present, and Future Further insights into lower mantle and core-mantle boundary are reviewed in Chapter 2.03. Although major element chemistry of the mantle is well studied, trace elements chemistry and role of volatiles in deep mantle are still in their infancy. This aspect is vital for understanding planetary formation, core segregation, and Earth's evolution (see Volumes 9 and 10). Chapter 2.04 reviews this aspect while significant progress on core nature and evolution is provided in Chapter 2.05. Understanding lower mantle and core limits are reviewed in Chapters 2.06 and 2.13 using theory and experiment together. Chapter 2.06 outlines thermodynamic basis of high-pressure-high-temperature behavior, expanding on equations of state and material responses to pressure and temperature changes. Chapter 2.07 presents detailed analysis of lattice vibrations and spectroscopy of mantle minerals. Advances in computing power have enabled computational mineral physics contributions to understanding high-pressure minerals' thermodynamic, thermo-elastic, and dynamical properties. Recent quantum mechanical simulations achieve precision comparable with experiments (e.g., Price et al., 1987; Wall and Price, 1988). Ключевые слова: e, r, o