fissuresnarrow

Fissuresnarrow is a term that appears in niche geology and materials-science literature to describe either the state of a fissure that has become narrower or a class of fissures whose apertures are constrained to small widths. The usage is not standardized, and the term is not widely recognized as a formal technical definition.

In geological contexts, fissuresnarrow often refers to fissures with apertures in the micrometer to millimeter range. It is relevant to fracture mechanics and hydrogeology because narrower apertures can limit fluid flow, influence permeability, and affect groundwater transport in fractured rock. In engineering applications, recognizing fissuresnarrow features aids in assessing rock stability during excavation, tunneling, or grouting design.

Causes and processes that produce fissuresnarrow include mechanical closure from tectonic compression or overburden, stress redistribution after unloading, diagenetic sealing and mineral precipitation within the crack, swelling of clay minerals, and cementation that reduces fissure width over time.

Detection and measurement of fissuresnarrow rely on high-resolution imaging and analysis. Techniques such as micro-computed tomography, thin-section petrography, crack-seal analysis, and in situ pressure measurements help quantify aperture and its variation under stress. The main metric is aperture, often expressed in micrometers to millimeters, sometimes linked to shear displacement in models of fluid flow.

Relation to related terms: a fissure is a natural crack in rock; crack-seal or fracture sealing describes related sealing processes. The term fissuresnarrow should not be confused with fissure filling or fissure sealing used in civil engineering contexts.

See also: Fissure (geology), Aperture (geology), Fracture mechanics, Hydraulic conductivity, Rock mass rating.