This book presents the first overview of the composition and structure of the Earth's lower mantle. The first part focuses on the study of lower-mantle minerals, identified as inclusions in diamonds from different regions of the world. Three associations are established among the lower-mantle minerals: ultramafic, mafic, and carbonatic. The carbonatic association is of particular interest because it characterizes the media of natural diamond formation. In turn, the second part analyzes the structure of the lower mantle, revealing its heterogeneous composition. It is based on the results of experiments demonstrating phase transitions in lower-mantle minerals, and on seismological data. Deep-seated earthquakes point to the presence within the lower mantle of numerous seismic boundaries caused by mineral structure transitions. In closing, the last part of The Earth's Lower Mantle compares observed data with experimental data, highlighting several discrepancies that indicate Earth may have a more complex planetary history than previously assumed, and examining its primarily non-chondritic composition.
Introduction: History of the problem
1. Models of the Earth's mantle
2. High-pressure experimental data on ultramafic and mafic systems
3. Natural lower-mantle minerals
4. Carbonatitic association
5. Some problems in the mineral composition of the lower mantle
6. Iron spin crossover in lower mantle minerals
7. Phase transitions in lower-mantle minerals
8. Crystallographic features (regularities) of lower-mantle mineral phases
9. Changes in properties of chemical elements under high pressures and possible new mineral compounds in Deep Earth
10. Seismic inhomogeneities in the lower mantle and their nature
11. Local inhomogeneities in the lower mantle
12. Geochemistry of the lower mantle
13. Oxidation potential in the lower mantle
14. D" layer: transition from the lower mantle to the Earth's core. (Postperovskite and other minerals in the D" layer)
15. Conclusions
Further problems
References
Subject index