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Granitization is an old, and largely discounted, hypothesis that granite is formed in place through extreme metasomatism. The idea behind granitization was that fluids would supposedly bring in elements such as potassium, and remove others, such as calcium, to transform a metamorphic rock into granite.
Granitization, a discredited alternative to a magmatic origin of granites; Monoglaciation, the idea that the Earth had a single ice age, replaced by polyglaciation, the idea that the Earth has gone through several periods of widespread ice cover. [17] Oscillation theory of land-level rise and subsidence during deglaciation
Metasomatism (from the Greek μετά metá "change" and σῶμα sôma "body") is the chemical alteration of a rock by hydrothermal and other fluids. [1] It is traditionally defined as metamorphism which involves a change in the chemical composition, excluding volatile components. [2]
High-grade gold ore from the Harvard Mine, Jamestown, California, a wide quartz-gold vein in California's Mother Lode.Specimen is 3.2 cm (1.3 in) wide. Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust.
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts.
Granitization of the older sedimentary–volcogenic sequence are reported as sources of the peninsular gneisses made up of polyphase migmatites, gneisses and granites ranging in composition from granodiorite to tonalite.
Ptygmatic folding in migmatite on Naissaar Island, Estonia Migmatite on the coast of Saaremaa, Estonia Intricately-folded migmatite from near Geirangerfjord, Norway. Migmatite is a composite rock found in medium and high-grade metamorphic environments, commonly within Precambrian cratonic blocks.
The Eburnean orogeny, or Eburnean cycle, was a series of tectonic, metamorphic and plutonic events in what is now West Africa during the Paleoproterozoic era about 2200–2000 million years ago.