What does cataclasis mean?
Cataclasis is a geological term describing the deformation of rock by mechanical means — the fracturing, crushing, and grinding of mineral grains into progressively smaller pieces. It occurs chiefly along fault zones, where tectonic forces subject rock to intense stress at comparatively low temperatures, breaking brittle minerals rather than allowing them to flow plastically. The resulting finely comminuted material may form a fault gouge or consolidate into a distinctive fragmented rock called cataclasite. Geologists study cataclastic textures under the microscope because their grain-size reduction and angular fragment shapes preserve a record of past fault movement and deformation conditions. Derived from the Greek for 'breaking down', cataclasis is a specialized but precise word, essential vocabulary for anyone reading literature on fault mechanics, brittle deformation, or the architecture of earthquake-generating zones in the Earth's crust.
nounIn geology, the deformation of rocks through fracturing, crushing, and granulation of mineral grains, typically along fault zones under high pressure; the process produces a fine-grained rock known as cataclasite.
- The deformation and reduction of rock material to smaller fragments by fracturing, crushing, and grinding during tectonic movement, especially within fault zones.
"The fault zone showed intense cataclasis, with once-coarse granite reduced to a powdery, finely ground matrix."
"Microscopic examination revealed pervasive cataclasis in the quartz grains, evidence of ancient fault motion."
"Because cataclasis occurs at relatively shallow crustal levels, it contrasts with ductile flow seen deeper in the crust."
Rarely pluralized in practice; the singular is normally used even when referring to multiple instances.
"Distinct cataclases were recorded at several horizons within the core sample."
Earthquakes don't just shake rocks — deep along faults they grind them to powder, and that slow-motion pulverizing has its own name: cataclasis.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cataclasis
Cataclasis derives from the Greek noun kataklasis, meaning 'a breaking down' or 'shattering', formed from the prefix kata- ('down') and klasis ('a breaking'), itself from klan ('to break'). It shares this root family with other kata- compounds such as catastrophe and cataclysm, which likewise convey notions of overturning or ruinous change. The term was adopted into English geological usage in the late nineteenth century as geologists formalized the study of fault-zone deformation.
Related word forms
How cataclasis is actually used
A technical term used almost exclusively in structural geology and petrology; rarely encountered outside scientific literature. The adjective 'cataclastic' describes rocks or textures produced by this process.
Easily confused with cataclasis
A cataclysm is a large-scale, usually catastrophic event such as a flood or disaster (or in geology, a sudden violent upheaval), whereas cataclasis is specifically the mechanical grinding and fracturing of rock grains within a deformed zone.