fault breccia

geology

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June 26, 2026

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Fault breccia is a type of rock composed of angular fragments that result from movement along a fault. It is a form of breccia, which is a lithified sedimentary rock made up of angular or subangular fragments larger than 2 millimeters. This distinguishes it from conglomerate, which consists of rounded fragments.12

Breccias can be categorized into three types: sedimentary, pyroclastic or igneous, and cataclastic. The fragments within a fault breccia are specifically formed by the grinding and crushing action associated with tectonic faulting. These fragments can be cemented together by materials like carbonate or silica.21

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fault
…it is referred to as fault breccia. Occasionally, the beds adjacent to the fault plane fold or bend as they resist slippage because of friction. Areas of deep sedimentary rock cover often show no surface indications of the faulting below.
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…it is referred to as fault breccia. Occasionally, the beds adjacent to the fault plane fold or bend as they resist slippage because of friction. Areas of deep sedimentary rock cover often show no surface indications of the faulting below.
Read More