Detailansicht
Feldspars and Their Reactions
NATO Science Series C: (closed), Volume 421, Nato Science Series C: 421
ISBN/EAN: 9780792327226
Umbreit-Nr.: 1641903
Sprache:
Englisch
Umfang: xxx, 650 S.
Format in cm:
Einband:
gebundenes Buch
Erschienen am 28.02.1994
- Zusatztext
- Inhaltsangabe1. The Crystal Structures of the Aluminium-Silicate Feldspars.- Abstract.- 1. Introduction.- 1.1 Historical Perspective.- 1.2 Recent Progress and Overview.- 2. Chemistry of Feldspars.- 3. Topology of the Feldspar Framework.- 4. Patterns of Al, Si Order-Disorder: Space Groups.- 4.1 Alkali Feldspars.- 4.1.1 Monoclinic (C2/m) K-rich Alkali Feldspars.- 4.1.2 Triclinic ($$C\bar 1$$) K-rich Alkali Feldspars.- 4.1.3 Room-Temperature Phase Transition in Low Microcline?.- 4.1.4 Triclinic ($$C\bar 1$$) Anorthoclases, K-Analbites, and the Transition to C2/m Na-Sanidines.- 4.1.5 Triclinic ($$C\bar 1$$) Low, Intermediate, and High Albite.- 4.1.6 Analbite and the Transition to C2/m Monalbite.- 4.2 Celsian and Hyalophane.- 4.3 Anorthite and Intermediate Plagioclases.- 4.3.1 The 'Aluminium Avoidance' Principle and Al, Si order/disorder.- 4.3.2 Primitive Anorthite.- 4.3.3 Pseudo-symmetry and the Average Structure Concept.- 4.3.4 Body-centered Anorthite.- 4.3.5 Intermediate Plagioclases.- 5. The M Cations in Feldspar Structures.- 5.1 Potassium in Sanidines and Microclines.- 5.2 Sodium in Albites.- 5.2.1 Sodium in Low Albite.- 5.2.2 Sodium in High Albite and Monalbite.- 5.2.3 Sodium in Intermediate Albite (IA) and Na/Ca in Sodic Plagioclase.- 5.2.4 Ca/Na in Calcic Plagioclase.- 6. Average Structures of Feldspars Represented by Cell Parameters: the Temperature-Pressure-Composition Analogies.- 6.1 Changes in Volume with P, T, X.- 6.1.1 Compressibility and Phase Changes with Pressure.- 6.1.2 Thermal Expansion.- 6.1.3 Variation of Composition in 'Solid-Solution' Series.- 6.2 Changes in Cell Dimensions with P,T,X.- 6.2.1 Series of Na- and K- Mixed with Ca-, Sr-, and Ba-feldspars.- 6.2.2 The M2+-feldspars.- 6.2.3 Alkali Feldspars.- 6.3 Changes in T-O-T Angles and M-O Distances with P, T, X.- 6.3.1 Disordered Alkali Feldspars.- 6.3.2 Ordered Alkali Feldspars and the Structure of Low Albite at 5 GPa.- 7. Future Work.- References.- 2. Aspects of Alkali Feldspar Characterization: Prospects and Relevance to Problems Outstanding.- Abstract.- 1. Introduction.- 2 Light Optics.- 3. Composition and Lattice Strain.- 3.1 Composition of Unstrained Feldspars.- 3.2 Strained Feldspars.- 3.2.1 Background.- 3.2.2 Determination of Lattice Strain.- 3.2.3 Determination of Composition.- 3.3 Composition from K, Na Site Refinements of X-Ray Intensity Data.- 4. Determination of Tetrahedral Al Contents in Alkali Feldspars.- 4.1 T-Site Occupancies from Lattice Parameters.- 4.2 T-Site Occupancies from T-O Distances.- 4.3 T-Site Occupancies from Si, Al Site Refinements of X-Ray Intensity Data.- 5. Single-Crystal X-ray Diffraction Patterns and Relationships with TEM Techniques.- 5.1 The Diagonal Association.- 5.2 The Antidiagonal Association.- 5.3 P21/a Structural Arrangement.- 6. Unanswered questions and suggestions for future work.- Acknowledgements.- References.- 3. Phase Transitions and Vibrational Spectroscopy in Feldspars.- Abstract.- 1. Introduction.- 2. Phase Transitions and Order Parameters.- 2.1 The order Parameter.- 2.2 Coupling between order Parameters.- 2.3 Some Typical Landau Potentials.- 3. Kinetic and Other Non-Equilibrium Behaviour.- 4. Hard Mode Phonon Spectroscopy.- 4.1 Introductory Remarks on Optical Spectroscopy.- 4.2 Soft Modes Versus Hard Modes.- 4.3 The Characteristic Length Scale.- 4.4 How to Do It.- 5. Applications and Examples.- 5.1 Temperature Dependence of Hard Modes in Albite.- 5.2 Effect of the C2/m-$$C\bar 1$$ Transition in Anorthoclase.- 5.3 A Displacive Phase Transition with Some Fluctuations: $$P\bar 1 - I\bar 1$$ in Anorthite.- 5.3.1 Space Average Model.- 5.3.2 The Ca-jumping Model.- 5.3.3 Soft-mode Model.- 5.4 Determination of the Degree of Al, Si order in Na Feldspar.- 5.5 Structural Modulations in Natural Potassium Feldspar.- 5.6 On the Effect of Na-K Mixing and the Study of Exsolution: an Outlook.- Conclusion.- Acknowledgements.- Appendix 1.- Deviation of the Gibbs Free Energy for a Phase Transition with Continuous Local Potentials.- Appendi
- Kurztext
- The articles in this book review the chemical reactions of feldspars over the whole sweep of pressure and temperature regimes in the outer Earth, and describe the fundamental aspects of crystal structure which underlie their properties.