Precambrian Banded-Iron-Formations (eBook)

Front Cover 1
Precambrian Banded Iron-Formations: Physicochemical Conditions of Formation 4
Copyright Page 5
Contents 12
Preface to the English edition 6
Preface to the Russian edition 8
Chapter 1. PRECAMBRIAN BANDED IRON FORMATIONS, THEIR DISTRIBUTION AND THEIR AGE, SPATIAL AND GENETIC RELATIONSHIPS 14
Introduction 14
Geologic poaition of banded iron-formations 15
Relationship of volcanic and sedimentary processes in the formation of the banded iron-formations 29
Composition of banded iron-formations 35
Present ideas on the origin of the banded iron-formations 49
Chapter 2. CONDITIONS OF DEPOSITION IN THE PRECAMBRIAN 58
Introduction 58
Evolution of sedimentary processes 58
Geochemical history of the atmosphere and ocean in the Precambrian 61
Evolution of life in the Precambrian 91
Chapter 3. CONDITIONS OF MIGRATION AND DEPOSITION OF IRON AND SILICA 112
Introduction 112
Physicochemical data on the forms of transport and conditions of deposition of iron and silica 113
Geochemical data on the forms of transport and conditions of deposition of iron and silica in natural waters 149
Analysis of the energy of the processes of diagenesis of cherty iron sediments 166
Physicochemical model of the formation of cherty iron sediments in the Precambrian 187
Chapter 4. PHYSICOCHEMICAL CONDITIONS OF METAMORPHISM OF THE ROCKS OF THE PRECAMBRIAN CHERTY IRON-FORMATIONS 202
Introduction 202
Main factors in rnetamorphism 202
Thermodynamics of metamorphism of cherty iron sediments 210
Stability of the rocks of the BIF under the conditions of ultrametamorphism and granitization 253
Chapter 5. ON THE ORIGIN OF THE ORE MINERALS OF THE PRECAMBRIAN IRON-FORMATIONS 256
Introduction 256
Variations in the oxygen isotopic composition of the ore minerals and genesis of magnetite 257
Relationship of the occurrence of types of iron minerals to the content of carbon and some other elements 265
CONCLUSION 270
APPENDIX: System of consistent thermodynamic constants of minerals, sediments and ions 278
Wüstite 283
Stoichiometric wüstite 283
Nonstoichiometric wüstite 284
Magnetite 285
Hydromagnetite 286
Hematite 286
Goethite 287
Iron hydroxide 288
Hydrous ferrous oxide 289
Siderite 290
Fayalite 290
Ferrosilite 291
Grunerite 291
Minnesotaite 291
Greenalite 293
REFERENCES 296
SUBJECT INDEX 320