terrigenous

Terrigenous is an adjective used in geology and sedimentology to describe materials derived from land rather than formed in situ in marine or volcanic settings. In practice, terrigenous components include sediments and rocks produced by weathering and erosion of continental crust and delivered to adjacent basins by rivers, wind, ice, or gravity-driven transport. The term is often used interchangeably with lithogenic, though lithogenic can have broader usage in some contexts.

Terrigenous material is predominantly clastic, comprising minerals such as quartz, feldspar, and various clay minerals (for example illite, kaolinite, and smectite). The exact mineralogy reflects the source rocks and weathering intensity. Grain size and sorting depend on transport distance and energy: coarse sands and gravel near river mouths and shorelines, and finer silt and clay that can be dispersed widely by water or wind to deeper settings.

In marine and lacustrine geology, the terrigenous fraction is a key component used to interpret provenance, sediment transport, and paleoenvironmental conditions. Its relative abundance helps distinguish between environments dominated by land-derived input and those dominated by biogenic or hydrogenous sources. Terrigenous sediments are deposited in a range of settings, including continental shelves, deep-sea fans, and desert basins, and are commonly subject to diagenetic alteration during burial.