In this article we attempt to shed some light on the factors that determine whether volume-increasing reactions and growth in pores will reduce or increase permeability. We will start by describing fi eld-scale examples of reaction-driven fracturing, and use a Discrete Element Model (DEM) to analyze how the resulting pattern and the rate and progress of reaction depend on the initial porosity of the rock. Ultimately, however, stress generation is related to growth processes taking place at the pore scale. We will therefore zoom in and describe pore-scale growth processes and how these are associated with fracturing and the production of new reactive surface area and new transport channelways for migrating fl uids. Stress generation by growth in pores requires that crystals continue to grow even after having ‘hit’ the pore wall. This implies that the fl uid from which the crystals precipitate is not squeezed out from the reactive interface by the normal stress generated by the growth, but can be kept in place as a thin fi lm by opposing forces that operate at very small scales. To understand the dynamics of crystal growth against confi ning pore walls, we need to zoom in even further and examine interface processes taking place at the nanometer scale. Hence, the last part of this chapter focuses on the nanometer-scale morphology of the reacting interface and the mechanical and transport properties of the fl uids confi ned along reactive grain boundaries.
{"title":"Pore-Scale Controls on Reaction-Driven Fracturing","authors":"A. Røyne, B. Jamtveit","doi":"10.2138/RMG.2015.80.02","DOIUrl":"https://doi.org/10.2138/RMG.2015.80.02","url":null,"abstract":"In this article we attempt to shed some light on the factors that determine whether volume-increasing reactions and growth in pores will reduce or increase permeability. We will start by describing fi eld-scale examples of reaction-driven fracturing, and use a Discrete Element Model (DEM) to analyze how the resulting pattern and the rate and progress of reaction depend on the initial porosity of the rock. Ultimately, however, stress generation is related to growth processes taking place at the pore scale. We will therefore zoom in and describe pore-scale growth processes and how these are associated with fracturing and the production of new reactive surface area and new transport channelways for migrating fl uids. Stress generation by growth in pores requires that crystals continue to grow even after having ‘hit’ the pore wall. This implies that the fl uid from which the crystals precipitate is not squeezed out from the reactive interface by the normal stress generated by the growth, but can be kept in place as a thin fi lm by opposing forces that operate at very small scales. To understand the dynamics of crystal growth against confi ning pore walls, we need to zoom in even further and examine interface processes taking place at the nanometer scale. Hence, the last part of this chapter focuses on the nanometer-scale morphology of the reacting interface and the mechanical and transport properties of the fl uids confi ned along reactive grain boundaries.","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"28 1","pages":"25-44"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87549578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Porosity plays a clearly important role in geology. It controls fluid storage in aquifers, oil and gas fields and geothermal systems, and the extent and connectivity of the pore structure control fluid flow and transport through geological formations, as well as the relationship between the properties of individual minerals and the bulk properties of the rock. In order to quantify the relationships between porosity, storage, transport and rock properties, however, the pore structure must be measured and quantitatively described. The overall importance of porosity, at least with respect to the use of rocks as building stone was recognized by TS Hunt in his “Chemical and Geological Essays” (1875, reviewed by JD Dana 1875) who noted: > “Other things being equal, it may properly be said that the value of a stone for building purposes is inversely as its porosity or absorbing power.” In a Geological Survey report prepared for the U.S. Atomic Energy Commission, Manger (1963) summarized porosity and bulk density measurements for sedimentary rocks. He tabulated more than 900 items of porosity and bulk density data for sedimentary rocks with up to 2,109 porosity determinations per item. Amongst these he summarized several early studies, including those of Schwarz (1870–1871), Cook (1878), Wheeler (1896), Buckley (1898), Gary (1898), Moore (1904), Fuller (1906), Sorby (1908), Hirschwald (1912), Grubenmann et al. (1915), and Kessler (1919), many of which were concerned with rocks and clays of commercial utility. There have, of course, been many more such determinations since that time. There are a large number of methods for quantifying porosity, and an increasingly complex idea of what it means to do so. Manger (1963) listed the techniques by which the porosity determinations he summarized were made. He separated these into seven methods for …
{"title":"Characterization and Analysis of Porosity and Pore Structures","authors":"L. Anovitz, D. Cole","doi":"10.2138/RMG.2015.80.04","DOIUrl":"https://doi.org/10.2138/RMG.2015.80.04","url":null,"abstract":"Porosity plays a clearly important role in geology. It controls fluid storage in aquifers, oil and gas fields and geothermal systems, and the extent and connectivity of the pore structure control fluid flow and transport through geological formations, as well as the relationship between the properties of individual minerals and the bulk properties of the rock. In order to quantify the relationships between porosity, storage, transport and rock properties, however, the pore structure must be measured and quantitatively described. The overall importance of porosity, at least with respect to the use of rocks as building stone was recognized by TS Hunt in his “Chemical and Geological Essays” (1875, reviewed by JD Dana 1875) who noted: > “Other things being equal, it may properly be said that the value of a stone for building purposes is inversely as its porosity or absorbing power.” In a Geological Survey report prepared for the U.S. Atomic Energy Commission, Manger (1963) summarized porosity and bulk density measurements for sedimentary rocks. He tabulated more than 900 items of porosity and bulk density data for sedimentary rocks with up to 2,109 porosity determinations per item. Amongst these he summarized several early studies, including those of Schwarz (1870–1871), Cook (1878), Wheeler (1896), Buckley (1898), Gary (1898), Moore (1904), Fuller (1906), Sorby (1908), Hirschwald (1912), Grubenmann et al. (1915), and Kessler (1919), many of which were concerned with rocks and clays of commercial utility. There have, of course, been many more such determinations since that time. There are a large number of methods for quantifying porosity, and an increasingly complex idea of what it means to do so. Manger (1963) listed the techniques by which the porosity determinations he summarized were made. He separated these into seven methods for …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"29 1","pages":"61-164"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86477150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fluid flow and reactive transport is relevant to many subsurface applications including CO2 sequestration, miscible/immiscible displacements in enhanced oil recovery, wellbore acidization, pollutant transport, and leakage/remediation of nuclear waste repositories. In all these scenarios, one or more fluid phases flow through the complicated geometry of the pore space, while advecting one or more chemical species along their flow streamlines. Simultaneously, the chemical species undergo molecular diffusion, due to their Brownian motion, allowing them to randomly jump from one streamline to the next. In the case of fluid–fluid or fluid–mineral reactions, chemical species may be transformed, potentially leading to precipitation and/or dissolution of solid minerals that alter the geometry/topology of the pore space. This in turn affects the velocity field of flow, and thus transport via advection/diffusion. Such complicated feedback between these pore-scale processes could give rise to “emergent” manifestations at larger scales. These manifestations are referred to as “emergent” because they cannot be foreseen from the behavior of the individual pore-scale mechanisms involved. In order to make reliable predictions of flow and transport at any scale of interest, accurate models need to be developed. Two spatial scales are commonly identified with a porous medium: the “micro/pore scale” (1–100 μm) and the “macro/continuum scale” (>1 m). The former is the fundamental scale in which physical processes (flow, transport, and geochemistry) take place, and the porous medium is regarded as discrete in nature (void space vs. grain space). The latter is a more practical scale, where we would ultimately like to have a reliable description of flow and reactive transport, and the porous medium is regarded as a continuum. The macroscopic parameters appearing in the description of continuum models, such as permeability or dispersion coefficient, are typically extracted from experiments or stand-alone pore-scale simulations. While such a “hierarchical” upscaling approach is …
{"title":"Mesoscale and Hybrid Models of Fluid Flow and Solute Transport","authors":"Y. Mehmani, M. Balhoff","doi":"10.2138/RMG.2015.80.13","DOIUrl":"https://doi.org/10.2138/RMG.2015.80.13","url":null,"abstract":"Fluid flow and reactive transport is relevant to many subsurface applications including CO2 sequestration, miscible/immiscible displacements in enhanced oil recovery, wellbore acidization, pollutant transport, and leakage/remediation of nuclear waste repositories. In all these scenarios, one or more fluid phases flow through the complicated geometry of the pore space, while advecting one or more chemical species along their flow streamlines. Simultaneously, the chemical species undergo molecular diffusion, due to their Brownian motion, allowing them to randomly jump from one streamline to the next. In the case of fluid–fluid or fluid–mineral reactions, chemical species may be transformed, potentially leading to precipitation and/or dissolution of solid minerals that alter the geometry/topology of the pore space. This in turn affects the velocity field of flow, and thus transport via advection/diffusion. Such complicated feedback between these pore-scale processes could give rise to “emergent” manifestations at larger scales. These manifestations are referred to as “emergent” because they cannot be foreseen from the behavior of the individual pore-scale mechanisms involved. In order to make reliable predictions of flow and transport at any scale of interest, accurate models need to be developed. Two spatial scales are commonly identified with a porous medium: the “micro/pore scale” (1–100 μm) and the “macro/continuum scale” (>1 m). The former is the fundamental scale in which physical processes (flow, transport, and geochemistry) take place, and the porous medium is regarded as discrete in nature (void space vs. grain space). The latter is a more practical scale, where we would ultimately like to have a reliable description of flow and reactive transport, and the porous medium is regarded as a continuum. The macroscopic parameters appearing in the description of continuum models, such as permeability or dispersion coefficient, are typically extracted from experiments or stand-alone pore-scale simulations. While such a “hierarchical” upscaling approach is …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"48 1","pages":"433-459"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73058919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recent profusion of microscopic characterization methods applicable to Earth Science materials, many of which are described in this volume (Anovitz and Cole 2015, this volume; Noiriel 2015, this volume), suggests that we now have an unprecedented new ability to consider geochemical processes at the pore scale. These new capabilities offer the potential for a paradigm shift in the Earth Sciences that will allow us to understand and ultimately quantify such enigmas as the apparent discrepancy between laboratory and field rates (White and Brantley 2003) and the impact of geochemical reactions on the transport properties of subsurface materials (Steefel and Lasaga 1990, 1994; Steefel and Lichtner 1994; Xie et al. 2015). It has only gradually become apparent that many geochemical investigations of Earth materials have suffered (perhaps inadvertently) from the assumption of bulk or continuum behavior, leading to volume averaging of properties and processes that really need to be considered at the individual grain or pore scale. For example, a relationship between reaction-induced porosity and permeability change can perhaps be developed based on bulk samples, but ultimately a mechanistic understanding and robust predictive capability of the associated geochemical and physical processes will require a pore-scale view. The question still arises: Do we need pore-scale characterization and models in geochemistry and mineralogy? The laboratory–field rate discrepancy (or enigma) is a good example of where a pore-scale understanding may provide insights not easily achievable with bulk characterization and models. If the reasons for this apparent discrepancy between laboratory and field rates cannot be explained, then it appears unlikely that scientifically defensible and quantitative models for a number of important Earth Science applications ranging from chemical weathering and its effects on atmospheric CO2, to subsurface carbon sequestration, to nuclear waste storage, to contaminant remediation and transport, …
最近大量适用于地球科学材料的微观表征方法，其中许多都在本卷中描述(Anovitz和Cole 2015，本卷;Noiriel 2015，本卷)，表明我们现在有了前所未有的新能力来考虑孔隙尺度上的地球化学过程。这些新能力为地球科学的范式转变提供了潜力，这将使我们能够理解并最终量化诸如实验室和现场速率之间的明显差异(White和Brantley 2003)以及地球化学反应对地下物质输运性质的影响(stefel和Lasaga 1990,1994;stefel and Lichtner 1994;Xie et al. 2015)。只有逐渐变得明显的是，许多地球物质的地球化学研究都受到(也许是无意中)假设体积或连续行为的影响，导致了真正需要在单个颗粒或孔隙尺度上考虑的性质和过程的体积平均。例如，反应引起的孔隙度和渗透率变化之间的关系也许可以基于大量样品来开发，但最终对相关地球化学和物理过程的机理理解和强大的预测能力将需要孔隙尺度的观点。问题仍然存在:我们是否需要地球化学和矿物学中的孔隙尺度表征和模型?实验室现场的速率差异(或谜)是一个很好的例子，说明孔隙尺度的理解可能提供不容易通过体表征和模型实现的见解。如果不能解释实验室和现场速率之间这种明显差异的原因，那么似乎不太可能为许多重要的地球科学应用建立科学上站住脚的定量模型，这些应用包括化学风化及其对大气二氧化碳的影响、地下碳封存、核废料储存、污染物补救和运输……
{"title":"Micro-Continuum Approaches for Modeling Pore-Scale Geochemical Processes","authors":"C. Steefel, L. Beckingham, G. Landrot","doi":"10.2138/RMG.2015.80.07","DOIUrl":"https://doi.org/10.2138/RMG.2015.80.07","url":null,"abstract":"The recent profusion of microscopic characterization methods applicable to Earth Science materials, many of which are described in this volume (Anovitz and Cole 2015, this volume; Noiriel 2015, this volume), suggests that we now have an unprecedented new ability to consider geochemical processes at the pore scale. These new capabilities offer the potential for a paradigm shift in the Earth Sciences that will allow us to understand and ultimately quantify such enigmas as the apparent discrepancy between laboratory and field rates (White and Brantley 2003) and the impact of geochemical reactions on the transport properties of subsurface materials (Steefel and Lasaga 1990, 1994; Steefel and Lichtner 1994; Xie et al. 2015). It has only gradually become apparent that many geochemical investigations of Earth materials have suffered (perhaps inadvertently) from the assumption of bulk or continuum behavior, leading to volume averaging of properties and processes that really need to be considered at the individual grain or pore scale. For example, a relationship between reaction-induced porosity and permeability change can perhaps be developed based on bulk samples, but ultimately a mechanistic understanding and robust predictive capability of the associated geochemical and physical processes will require a pore-scale view. The question still arises: Do we need pore-scale characterization and models in geochemistry and mineralogy? The laboratory–field rate discrepancy (or enigma) is a good example of where a pore-scale understanding may provide insights not easily achievable with bulk characterization and models. If the reasons for this apparent discrepancy between laboratory and field rates cannot be explained, then it appears unlikely that scientifically defensible and quantitative models for a number of important Earth Science applications ranging from chemical weathering and its effects on atmospheric CO2, to subsurface carbon sequestration, to nuclear waste storage, to contaminant remediation and transport, …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"2 1","pages":"217-246"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87213719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weathering of bedrock to produce porous regolith, the precursor to biologically active soil and soluble mineral nutrients, creates the life-supporting matrix upon which Earth’s Critical Zone—the thin surface layer where rock meets life—develops (Ollier 1985; Graham et al. 1994; Taylor and Eggleston 2001). Water and nutrients locked up in low porosity bedrock are biologically inaccessible until weathering helps transform the inert rock into a rich habitat for biological activity. Weathering increases the water-holding capacity and nutrient accessibility of rock and regolith by increasing porosity and mineral surface area, affecting the particle-size distribution, and enhancing ecosystem diversity (Cousin et al. 2003; Certini et al. 2004; Zanner and Graham 2005). Especially in areas where soils are thin and climate is dry, the water stored in weathered rock is essential to ecosystem productivity and survival (Sternberg et al. 1996; Zwieniecki and Newton 1996; Hubbert et al. 2001; Witty et al. 2003). Removal of soluble material during weathering decreases the concentrations of major elements such as Ca, Na, and Mg and the overall mass of the solid, decreasing the bulk density and increasing porosity. These chemical and physical changes result in decreased uniaxial compressive strength and elastic moduli of the rock and increased infiltration of water through the weathered rock (Tugrul 2004). Porosity in intact bedrock is comprised of inter- and intra-granular pores developed during (re-) crystallization in igneous and metamorphic rocks or diagenesis in sedimentary rocks. As we conceptualize it, the conversion of low-permeability bedrock to regolith generally begins due to the transport of meteoric water into protolith through the large-scale fractures that are present as a result of regional tectonic factors or exhumation (Wyrick and Borchers 1981; Molnar et al. 2007). In zones near the fractures, water can infiltrate into the low-porosity rock …
基岩风化产生多孔风化层，这是生物活性土壤和可溶性矿物质营养物质的前身，创造了支持生命的基质，地球的关键地带——岩石与生命相遇的薄表层(Ollier 1985;Graham et al. 1994;Taylor and Eggleston 2001)。锁在低孔隙度基岩中的水和营养物质在生物上是不可接近的，直到风化作用帮助惰性岩石转变为生物活动的丰富栖息地。风化作用通过增加孔隙度和矿物表面积、影响颗粒大小分布和增强生态系统多样性，增加岩石和风化层的持水能力和养分可及性(Cousin et al. 2003;Certini et al. 2004;Zanner and Graham 2005)。特别是在土壤稀薄和气候干燥的地区，风化岩石中储存的水对生态系统的生产力和生存至关重要(Sternberg等人，1996;Zwieniecki and Newton 1996;Hubbert et al. 2001;Witty et al. 2003)。风化过程中可溶性物质的去除降低了主要元素如Ca、Na和Mg的浓度，降低了固体的总质量，降低了堆积密度，增加了孔隙率。这些化学和物理变化导致岩石的单轴抗压强度和弹性模量下降，并增加了水通过风化岩石的渗透性(Tugrul 2004)。完整基岩的孔隙由岩浆岩、变质岩(再)结晶或沉积岩成岩作用形成的粒间和粒内孔隙组成。在我们的概念中，低渗透基岩向风化层的转化通常是由于区域构造因素或挖掘导致的大规模裂缝将大气水输送到原岩中(Wyrick and Borchers 1981;Molnar et al. 2007)。在裂缝附近的区域，水可以渗透到低孔隙度的岩石中。
{"title":"How Porosity Increases During Incipient Weathering of Crystalline Silicate Rocks","authors":"A. Navarre‐Sitchler, S. Brantley, G. Rother","doi":"10.2138/RMG.2015.80.10","DOIUrl":"https://doi.org/10.2138/RMG.2015.80.10","url":null,"abstract":"Weathering of bedrock to produce porous regolith, the precursor to biologically active soil and soluble mineral nutrients, creates the life-supporting matrix upon which Earth’s Critical Zone—the thin surface layer where rock meets life—develops (Ollier 1985; Graham et al. 1994; Taylor and Eggleston 2001). Water and nutrients locked up in low porosity bedrock are biologically inaccessible until weathering helps transform the inert rock into a rich habitat for biological activity. Weathering increases the water-holding capacity and nutrient accessibility of rock and regolith by increasing porosity and mineral surface area, affecting the particle-size distribution, and enhancing ecosystem diversity (Cousin et al. 2003; Certini et al. 2004; Zanner and Graham 2005). Especially in areas where soils are thin and climate is dry, the water stored in weathered rock is essential to ecosystem productivity and survival (Sternberg et al. 1996; Zwieniecki and Newton 1996; Hubbert et al. 2001; Witty et al. 2003). Removal of soluble material during weathering decreases the concentrations of major elements such as Ca, Na, and Mg and the overall mass of the solid, decreasing the bulk density and increasing porosity. These chemical and physical changes result in decreased uniaxial compressive strength and elastic moduli of the rock and increased infiltration of water through the weathered rock (Tugrul 2004). Porosity in intact bedrock is comprised of inter- and intra-granular pores developed during (re-) crystallization in igneous and metamorphic rocks or diagenesis in sedimentary rocks. As we conceptualize it, the conversion of low-permeability bedrock to regolith generally begins due to the transport of meteoric water into protolith through the large-scale fractures that are present as a result of regional tectonic factors or exhumation (Wyrick and Borchers 1981; Molnar et al. 2007). In zones near the fractures, water can infiltrate into the low-porosity rock …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"16 1","pages":"331-354"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77062098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Knowledge of the electronic structure of crystalline and non-crystalline earth materials at ambient and high pressure are essential in order to understand the atomic origins of electronic, thermodynamic, and mechanical properties of these materials in the Earth’s crust as well as Earth and planetary interiors (Hemley 1998; Laudernet et al. 2004; Stixrude and Karki 2005; Mao and Mao 2007; Price 2007; Stixrude 2007). Pressure-induced changes in the electronic structure of crystalline and amorphous silicates and oxides (glasses and melts) with low- z elements (e.g., Si, O, B, Li, C, etc.) have implications for diverse geophysical and magmatic processes relevant to the evolution and differentiation of the earth (e.g., mantle convection and mantle melting) (Stebbins 1995; Wolf and McMillan 1995; Lee 2005, 2011; Mysen and Richet 2005; Murakami and Bass 2010). Despite this importance, the analysis of the effect of pressure on the electronic structure and the nature of bonding in the crystalline and, particularly, non-crystalline oxides has remained one of the challenging problems in mineral physics and geochemistry, as well as, condensed matter physics. This is mostly because of the lack of suitable experimental probes of electronic bonding around these light elements in the earth materials under pressure. Advances in in situ high pressure technologies, together with progress in X-ray optics in synchrotron radiation and first principle calculations have revealed structural details of bonding transitions of crystalline earth materials at high pressure (Hemley 1998; Mao and Mao 2007; Price 2007; Stixrude 2007). The non-resonant synchrotron inelastic X-ray scattering (NRIXS, also known as X-ray Raman, XRS) is one of the relatively new synchrotron X-ray probes of local structures with element-specificity. It explores the electronic bonding transitions in soft X-ray absorption edges using hard X-rays (e.g., ~ 10 keV) …
为了理解地壳以及地球和行星内部这些材料的电子、热力学和机械特性的原子起源，了解环境和高压下晶体和非晶体地球材料的电子结构是必不可少的(Hemley 1998;Laudernet et al. 2004;Stixrude and Karki 2005;毛和毛2007;价格2007;Stixrude 2007)。具有低z元素(如Si, O, B, Li, C等)的晶体和非晶态硅酸盐和氧化物(玻璃和熔体)的电子结构的压力诱导变化对与地球演化和分化相关的各种地球物理和岩浆过程(如地幔对流和地幔熔融)具有影响(Stebbins 1995;Wolf and McMillan 1995;Lee 2005,2011;Mysen and Richet 2005;Murakami and Bass 2010)。尽管如此，分析压力对晶体，特别是非晶体氧化物中电子结构和键合性质的影响仍然是矿物物理学和地球化学以及凝聚态物理学中具有挑战性的问题之一。这主要是由于缺乏合适的实验探针，可以在地球材料中这些轻元素在压力下进行电子键合。原位高压技术的进步，以及同步辐射x射线光学和第一性原理计算的进展，揭示了晶体地球材料在高压下键合转变的结构细节(Hemley 1998;毛和毛2007;价格2007;Stixrude 2007)。非共振同步加速器非弹性x射线散射(NRIXS，又称x射线拉曼，XRS)是一种相对较新的具有元素特异性的局部结构同步加速器x射线探针。它利用硬x射线(例如~ 10 keV)探索软x射线吸收边缘的电子成键跃迁。
{"title":"Probing of Pressure-Induced Bonding Transitions in Crystalline and Amorphous Earth Materials: Insights from X-ray Raman Scattering at High Pressure","authors":"S. Lee, P. Eng, H. Mao","doi":"10.2138/RMG.2014.78.4","DOIUrl":"https://doi.org/10.2138/RMG.2014.78.4","url":null,"abstract":"Knowledge of the electronic structure of crystalline and non-crystalline earth materials at ambient and high pressure are essential in order to understand the atomic origins of electronic, thermodynamic, and mechanical properties of these materials in the Earth’s crust as well as Earth and planetary interiors (Hemley 1998; Laudernet et al. 2004; Stixrude and Karki 2005; Mao and Mao 2007; Price 2007; Stixrude 2007). Pressure-induced changes in the electronic structure of crystalline and amorphous silicates and oxides (glasses and melts) with low- z elements (e.g., Si, O, B, Li, C, etc.) have implications for diverse geophysical and magmatic processes relevant to the evolution and differentiation of the earth (e.g., mantle convection and mantle melting) (Stebbins 1995; Wolf and McMillan 1995; Lee 2005, 2011; Mysen and Richet 2005; Murakami and Bass 2010). Despite this importance, the analysis of the effect of pressure on the electronic structure and the nature of bonding in the crystalline and, particularly, non-crystalline oxides has remained one of the challenging problems in mineral physics and geochemistry, as well as, condensed matter physics. This is mostly because of the lack of suitable experimental probes of electronic bonding around these light elements in the earth materials under pressure.\u0000\u0000Advances in in situ high pressure technologies, together with progress in X-ray optics in synchrotron radiation and first principle calculations have revealed structural details of bonding transitions of crystalline earth materials at high pressure (Hemley 1998; Mao and Mao 2007; Price 2007; Stixrude 2007). The non-resonant synchrotron inelastic X-ray scattering (NRIXS, also known as X-ray Raman, XRS) is one of the relatively new synchrotron X-ray probes of local structures with element-specificity. It explores the electronic bonding transitions in soft X-ray absorption edges using hard X-rays (e.g., ~ 10 keV) …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"72 1","pages":"139-174"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82393277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brillouin spectroscopy is an optical technique that allows one to determine the directional dependence of acoustic velocities in minerals and materials subject to a wide range of environmental conditions. It is based on the inelastic scattering of light by spontaneous collective motions of particles in a material in the frequency range between 10−2 to 10 GHz. Brillouin spectroscopy is used to determine acoustic velocities and elastic properties of a number of crystalline solids, glasses, and liquids. It is most commonly performed on transparent single crystals where the complete elastic tensor of the sample material can be derived. However, Brillouin spectra can be also measured from opaque materials, from which partial or complete information on the elastic tensor can be determined. It is a very flexible technique with many possible areas of application in research disciplines from condensed matter physics to biophysics to materials sciences to geophysics. Brillouin scattering can be performed on very small samples and it can be easily combined with the diamond anvil cell and carried out at high pressures and temperatures (see reviews by Grimsditch and Polian 1989 and Eremets 1996). This makes this technique the method of choice to study the elastic properties of deep Earth materials, relevant to construct a mineralogical model of the interior of our planet that is consistent with the constraints from seismology. Several of the candidate minerals of the Earth’s interior are not stable at ambient conditions, and only recently has there been substantial progress in their synthesis. Unfortunately, those deep earth minerals that can be metastably preserved at ambient pressure and temperature are only available as single crystals with sizes of the order of several tens of microns at most. However, crystals of this size are large enough for Brillouin scattering to be performed. In addition, more sophisticated methods …
{"title":"Brillouin Scattering and its Application in Geosciences","authors":"S. Speziale, H. Marquardt, T. Duffy","doi":"10.2138/RMG.2014.78.14","DOIUrl":"https://doi.org/10.2138/RMG.2014.78.14","url":null,"abstract":"Brillouin spectroscopy is an optical technique that allows one to determine the directional dependence of acoustic velocities in minerals and materials subject to a wide range of environmental conditions. It is based on the inelastic scattering of light by spontaneous collective motions of particles in a material in the frequency range between 10−2 to 10 GHz. Brillouin spectroscopy is used to determine acoustic velocities and elastic properties of a number of crystalline solids, glasses, and liquids. It is most commonly performed on transparent single crystals where the complete elastic tensor of the sample material can be derived. However, Brillouin spectra can be also measured from opaque materials, from which partial or complete information on the elastic tensor can be determined. It is a very flexible technique with many possible areas of application in research disciplines from condensed matter physics to biophysics to materials sciences to geophysics. Brillouin scattering can be performed on very small samples and it can be easily combined with the diamond anvil cell and carried out at high pressures and temperatures (see reviews by Grimsditch and Polian 1989 and Eremets 1996). This makes this technique the method of choice to study the elastic properties of deep Earth materials, relevant to construct a mineralogical model of the interior of our planet that is consistent with the constraints from seismology. Several of the candidate minerals of the Earth’s interior are not stable at ambient conditions, and only recently has there been substantial progress in their synthesis. Unfortunately, those deep earth minerals that can be metastably preserved at ambient pressure and temperature are only available as single crystals with sizes of the order of several tens of microns at most. However, crystals of this size are large enough for Brillouin scattering to be performed. In addition, more sophisticated methods …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"199 1","pages":"543-603"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72832042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arsenic is dispersed widely in nature and is the 47th most abundant element among the 88 known natural elements. The average crustal abundance is 1.5 ppm, with higher concentrations in reduced shales and coals. It is concentrated in many metal-bearing mineral deposits being a chalcophile element. It occurs in many metallic deposits including those of Cu, Ag, Au, Zn, Hg, U, Sn, Pb, Mo, W, Ni, Co and PGE. Arsenic is often more dispersed than ore minerals in those deposits and as such is a useful indicator in geochemical exploration (Boyle and Jonasson 1973; Hale 1981; Cohen and Bowell 2014). Consequently, elevated concentrations of As are common in mine waste and process waste from metal-bearing ores (Bowell et al. 1994, 2013; Thornton 1994; Craw and Pacheco 2002; Lazareva et al. 2002). In particular, As is the main element of environmental concern in most hardrock mines. In this chapter, we outline the principal occurrences of As at mine sites, and their environmental significance. As an example of the detailed controls on As geochemistry in mine waste we focus on the gold mines in New Zealand. Many mines are significant point sources for As in the environment, and some mine sites have high concentrations of As locally, often exceeding 1% in ore or waste. For almost all of these mines, the As is a natural but undesirable component of the ore, and therefore the As is discarded with the rest of the mine wastes. Hence, mine wastes, especially mine tailings, are major repositories of As and have to be managed carefully. View this table: Table 1 Major primary mineral hosts for As in mine waste. Arsenic is an especially common constituent of sulfide-bearing mineral deposits, where As typically occurs either as separate As minerals (Table 1) or in solid solution …
砷在自然界分布广泛，是已知的88种天然元素中含量第47多的元素。平均地壳丰度为1.5 ppm，在还原页岩和煤中浓度较高。它作为一种亲铜元素富集在许多含金属矿床中。它存在于Cu、Ag、Au、Zn、Hg、U、Sn、Pb、Mo、W、Ni、Co、PGE等多种金属矿床中。在这些矿床中，砷往往比矿石矿物更分散，因此是地球化学勘探的有用指标(Boyle和Jonasson, 1973;黑尔1981;Cohen and Bowell 2014)。因此，砷浓度升高在矿山废物和含金属矿石的加工废物中很常见(Bowell等，1994,2013;桑顿1994;克劳和帕切科2002;Lazareva et al. 2002)。特别是，砷是大多数硬岩矿环境问题的主要因素。在本章中，我们概述了砷在矿区的主要成因及其环境意义。作为详细控制矿山废物中砷地球化学的一个例子，我们重点介绍了新西兰的金矿。许多矿山是环境中砷的重要点源，一些矿场在当地的砷浓度很高，矿石或废物中的砷含量往往超过1%。对几乎所有这些矿山来说，砷是矿石中一种天然但不受欢迎的成分，因此砷与矿山其他废物一起被丢弃。因此，矿山废料，特别是矿山尾矿是砷的主要储存库，必须谨慎管理。表1矿山废弃物中砷的主要原生矿物寄主。砷是含硫化物矿床的一种特别常见的成分，在这些矿床中，砷通常以单独的砷矿物(表1)或以固溶体形式存在……
{"title":"The Characterization of Arsenic in Mine Waste","authors":"D. Craw, R. Bowell","doi":"10.2138/RMG.2014.79.10","DOIUrl":"https://doi.org/10.2138/RMG.2014.79.10","url":null,"abstract":"Arsenic is dispersed widely in nature and is the 47th most abundant element among the 88 known natural elements. The average crustal abundance is 1.5 ppm, with higher concentrations in reduced shales and coals. It is concentrated in many metal-bearing mineral deposits being a chalcophile element. It occurs in many metallic deposits including those of Cu, Ag, Au, Zn, Hg, U, Sn, Pb, Mo, W, Ni, Co and PGE. Arsenic is often more dispersed than ore minerals in those deposits and as such is a useful indicator in geochemical exploration (Boyle and Jonasson 1973; Hale 1981; Cohen and Bowell 2014). Consequently, elevated concentrations of As are common in mine waste and process waste from metal-bearing ores (Bowell et al. 1994, 2013; Thornton 1994; Craw and Pacheco 2002; Lazareva et al. 2002). In particular, As is the main element of environmental concern in most hardrock mines. In this chapter, we outline the principal occurrences of As at mine sites, and their environmental significance. As an example of the detailed controls on As geochemistry in mine waste we focus on the gold mines in New Zealand. Many mines are significant point sources for As in the environment, and some mine sites have high concentrations of As locally, often exceeding 1% in ore or waste. For almost all of these mines, the As is a natural but undesirable component of the ore, and therefore the As is discarded with the rest of the mine wastes. Hence, mine wastes, especially mine tailings, are major repositories of As and have to be managed carefully. View this table: Table 1 Major primary mineral hosts for As in mine waste. Arsenic is an especially common constituent of sulfide-bearing mineral deposits, where As typically occurs either as separate As minerals (Table 1) or in solid solution …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"196 1","pages":"473-505"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79901013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The thin, smooth curves representing spectroscopic data suggest a high degree of accuracy. Yet, experimental uncertainties do exist, as in any measurement. Overlooked problems in data collection, processing, and interpretation have repercussions for applications in mineral physics, planetary science, and astronomy. Random errors (i.e., noise) are fairly obvious, and are not discussed here. The concern is subtle and overlooked errors that arise in acquisition, processing, and interpretation of spectral data. These types of errors are systematic, not random. This chapter identifies various systematic errors and problems that the author encountered in her efforts to provide absolute values of absorbance or reflectivity. Re-occurring issues in data collection include underestimating the importance of surface polish and not accounting for peak profiles depending on sample thickness relative to band strengths. Processing of emission spectra is problematic. Common instrumental problems are briefly described. Optical spectroscopy is the name generally attached to the visible region which we probe with our eyes, which are convenient built-in spectrometers, but can also include the infrared (IR) region wherein the type of vibrational mode known as “optical” is detected. Because some applications require very high frequency (ν) data, this chapter concerns ν from ~10 to 106 wavenumbers, which is equivalent to wavelengths (λ) of ~106 to 10 nm or of ~1000 to 0.01 μm). The X-ray region is included due to the extreme breadths of metal-oxygen charge-transfer bands of minerals which peak in the ultraviolet (UV). The author points out errors in her own results as well those of others. Mistakes provide opportunity for learning! Correct methodologies are discussed along with measurements needed to improve constraints on spectral parameters and hence to make interpretations more definitive. Ideal conditions are difficult to achieve, so another goal is enable the reader to recognize what is “sufficiently accurate” and/or “representative” …
{"title":"Carryover of Sampling Errors and Other Problems in Far-Infrared to Far-Ultraviolet Spectra to Associated Applications","authors":"A. Hofmeister","doi":"10.2138/RMG.2014.78.12","DOIUrl":"https://doi.org/10.2138/RMG.2014.78.12","url":null,"abstract":"The thin, smooth curves representing spectroscopic data suggest a high degree of accuracy. Yet, experimental uncertainties do exist, as in any measurement. Overlooked problems in data collection, processing, and interpretation have repercussions for applications in mineral physics, planetary science, and astronomy. Random errors (i.e., noise) are fairly obvious, and are not discussed here. The concern is subtle and overlooked errors that arise in acquisition, processing, and interpretation of spectral data. These types of errors are systematic, not random. This chapter identifies various systematic errors and problems that the author encountered in her efforts to provide absolute values of absorbance or reflectivity. Re-occurring issues in data collection include underestimating the importance of surface polish and not accounting for peak profiles depending on sample thickness relative to band strengths. Processing of emission spectra is problematic. Common instrumental problems are briefly described. Optical spectroscopy is the name generally attached to the visible region which we probe with our eyes, which are convenient built-in spectrometers, but can also include the infrared (IR) region wherein the type of vibrational mode known as “optical” is detected. Because some applications require very high frequency (ν) data, this chapter concerns ν from ~10 to 106 wavenumbers, which is equivalent to wavelengths (λ) of ~106 to 10 nm or of ~1000 to 0.01 μm). The X-ray region is included due to the extreme breadths of metal-oxygen charge-transfer bands of minerals which peak in the ultraviolet (UV). The author points out errors in her own results as well those of others. Mistakes provide opportunity for learning! Correct methodologies are discussed along with measurements needed to improve constraints on spectral parameters and hence to make interpretations more definitive. Ideal conditions are difficult to achieve, so another goal is enable the reader to recognize what is “sufficiently accurate” and/or “representative” …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"2014 1","pages":"481-508"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86693600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Analytical transmission electron microscopy (TEM) is used to reveal sub-micrometer, internal fine structure (the microstructure or ultrastructure ) and chemistry in minerals. The amount and scale of the information which can be extracted by TEM depends critically on four parameters; the resolving power of the microscope (usually smaller than 0.3 nm); the energy spread of the electron beam (of the order of an electron volt, eV); the thickness of the specimen (almost always significantly less than 1 μm), and the composition and stability of the specimen. An introductory text on all types of electron microscopy is provided by Goodhew et al. (2001), while more detailed information on transmission electron microscopy may be found in the comprehensive text of Williams and Carter (2009). ### Basic design of transmission electron microscopes (TEM) The two available modes of TEM—CTEM and STEM—differ principally in the way they address the specimen. Conventional TEM (CTEM) is a wide-beam technique, in which a close-to-parallel electron beam floods the whole area of interest and the image (or diffraction pattern), formed by an imaging (objective) lens after the thin specimen from perhaps 106–107 pixels on a digital camera, is collected in parallel . Scanning TEM (STEM) deploys a fine focused beam, formed by a probe-forming lens before the thin specimen, to address each pixel (here, a dwell point) in series and form a sequential image as the probe is scanned across the specimen. Figures 1 and 2 summarize these different instrument designs; here it should be noted that many modern TEM instruments are capable of operating in both modes, rather than being instruments dedicated to one mode of operation. In both types of instrument analytical information from a small region is usually collected using a focused beam. The smallest region from which an analysis can be collected is defined by the diameter of …
{"title":"Analytical transmission electron microscopy","authors":"R. Brydson, A. Brown, L. Benning, K. Livi","doi":"10.2138/rmg.2014.78.6","DOIUrl":"https://doi.org/10.2138/rmg.2014.78.6","url":null,"abstract":"Analytical transmission electron microscopy (TEM) is used to reveal sub-micrometer, internal fine structure (the microstructure or ultrastructure ) and chemistry in minerals. The amount and scale of the information which can be extracted by TEM depends critically on four parameters; the resolving power of the microscope (usually smaller than 0.3 nm); the energy spread of the electron beam (of the order of an electron volt, eV); the thickness of the specimen (almost always significantly less than 1 μm), and the composition and stability of the specimen. An introductory text on all types of electron microscopy is provided by Goodhew et al. (2001), while more detailed information on transmission electron microscopy may be found in the comprehensive text of Williams and Carter (2009). ### Basic design of transmission electron microscopes (TEM) The two available modes of TEM—CTEM and STEM—differ principally in the way they address the specimen. Conventional TEM (CTEM) is a wide-beam technique, in which a close-to-parallel electron beam floods the whole area of interest and the image (or diffraction pattern), formed by an imaging (objective) lens after the thin specimen from perhaps 106–107 pixels on a digital camera, is collected in parallel . Scanning TEM (STEM) deploys a fine focused beam, formed by a probe-forming lens before the thin specimen, to address each pixel (here, a dwell point) in series and form a sequential image as the probe is scanned across the specimen. Figures 1 and 2 summarize these different instrument designs; here it should be noted that many modern TEM instruments are capable of operating in both modes, rather than being instruments dedicated to one mode of operation. In both types of instrument analytical information from a small region is usually collected using a focused beam. The smallest region from which an analysis can be collected is defined by the diameter of …","PeriodicalId":49624,"journal":{"name":"Reviews in Mineralogy & Geochemistry","volume":"1 1","pages":"219-269"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79823907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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