Crystals in geological processes 1300-WKPG3L1

The general characteristics of crystals and crystallization processes. Morphology and internal structure of crystals - the ideal and real crystals. Blocky structure of crystals, subcrystals and crystallites. Crystal nucleation in natural environments, CDS diagrams. Growth of single crystals. Growth zoning and growth sectors, growth accessories. Growth zoning as the record of crystallization history. Crystal morphology as the indicator of environmental conditions. Evolution of crystal morphology during growth. Concept of mineral typomorphism. Asymmetric development of crystals and its causes. "Geotrophism" of crystals. Crystals growing in the streams of mineralizing solutions. Twisted and curved crystals, skeletal crystals, dendrites, fibrous crystals - examples from natural environments. Growth of crystals in free space and among foreign bodies; incorporative, displacive and replacive growth. Force of crystallization. Growth of crystal aggregates. Crystal druses and drusy aggregates. Induction (compromise) surfaces, competitive growth. Splitting of the growing crystals. Spherulites and their growth on the substrate. Aggregates of fibrous crystals. Ataxial, syntaxial and antitaxial veins. Oriented crystal intergrowths. Growth, transformation and gliding twins. Epitaxial intergrowths. Deformation, destruction and transformations of natural crystals. Dissolution of crystals, etch figures, negative crystals, pseudomorphs. Recrystallization. Neomorphism. Crystal growth in selected environments: Accretion of ooids in turbulent water. Snow-ball theory. Growth of calcite and aragonite crystals in speleothems, travertines, and on the sea-floor. Precipitation and growth of crystals in brines of evaporite basins. Crystals as cements in sedimentary rocks. Syntaxial growth. Ice crystals in nature: snow, firn, glacier ice. Flow of glacier ice. Halite crystals in processes of halokinesis and salt diapirism. Salt glaciers. Crystals in tectonic deformations and metamorphic processes. Elements of petrotectonics. Pre-, syn- and postkinematic crystallization. Crystal growth in magmatic processes. Graphic intergrowths in pegmatites. Crystals in living organisms. Biomineralization. Crystals and chiral organic compounds. Crystals and creation of life on Earth.