Cataclastic rocks

Abstract

Cataclastic rocks with primary cohesion. __________ Cataclasis dominant_______________________ Rocks without fluxion structure._________ Series: microbreccia-cataclasite _______ Microbreccia. __________________ Cataclasite... __________________ Rocks with fluxion structure _____________ Series: protomylonite-mylonite-ultramylonite ___-___ _____..____-_____ Protomylonite. _________________ Mylonite_ _____________________ Ultramylcnite_ _________________ Phyllonite; a variety of mylonite and ultramylonite. _ __________________ Neomineralization-recrystallization dominant. __ Series: mylonite gneiss (mylonite schist)blasto mylonite _______________________ Mylonite gneiss (mylonite schist) _____ Blastomylonite. ____________________ Protoclastic rocks.._________________________ Retrograde Cataclastic rocks_________________ Cataclastic rocks in which fusion or melting was important-. _ _____________________________ Pseudotachylite. _______________________ Hartschiefer_ _____________________________ Polycataclastic and polymetamorphic Cataclastic rocks.___________________________________ Problems of nomenclature and classification of Cataclastic rocks._____________________________ Mineral assemblage and chemical composition. _ Petrofabrics._ ______________________________ Approximate percentage and size of porphyroclasts and rock fragments (grain size) _______ Defining degree of neomineralization-recrys-tallization__ _ _____________________________ Field relations of cataclastic rocks.___________________ Recognition of faults and fault zones._____________ Recognition of cataclastic rocks __________________ Mafic cataclastic rocks._________________________ Association of cataclasis with felsic and silicic intrusive rocks.______________________________ Late mineralization of cataclastic rocks and cataclastic rock zones.

Structural and chemical characterization of shear zones in the freshly activated Nojima fault, Awaji Island, southwest Japan

“…As a result, rock in the drill core were categorized into the following eight types: (1) granodiorite (host rock), (2) porphyry intrusions (host rock), (3) WPAR, (4) fault breccia, (5) cataclasite, (6) ultracataclasite, (7) pseudotachylite, and (8) fault gouge. Types 3-8 correspond to the fault rock classification followed by Higgins [1971] Step 2 • Entoring tho oriontation roloronco lings onto tho core pieces…”

Geology of the chibex gold deposit, Chibougamau, Quebec /

“…Cataclastic textures similar to those described and defined by Higgins (1971) are seen in most altered rooks» In general, oataclasis has localized effect and intensities of metasomatism. The result is that the degree of total recrystallization and production of secondary minerals such as chlorite and epidote is related to the degree of cataclasis with the exception of development of the carbonate and tourmaline* 2.…”

“…Fluxion textures (such as described by Higgins, 1971) are often shown around amphiboles and less often around the plagioclase in the gabbro.…”

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“…El término cataclástico se refiere a la textura deformativa en que predominan los efectos mecánicos sobre los de recristalización y/o neomineralización, que se desarrollan en ambientes más superficiales; mientras que el término milonítico, se reserva para aquellas rocas en las que estos últimos son predominantes y que son típicos de ambientes más profundos donde los procesos plásticos son más importantes que los de índole frágil (Higgins, 1971).…”

“…Estas observaciones fueron corroboradas por medio de otros estudios estructurales a escalas micro, meso y macroscópica. Estas rocas, en la clasificación de Higgins (1971), son denominadas protomilonitas y milonitas; mientras que de acuerdo a los conceptos de Belliere (1971) basados en función de profundidad (condiciones regionales de presión y temperatura) la zona de origen correspondería a la Epizona inferior y Mesozona superior (Facies Esquistos Verdes).…”