terrigenous facies

In geology, a terrigenous facies refers to sedimentary rocks formed from the accumulation of particles eroded from older rocks and transported to a depositional site. These sediments are derived from land sources and carried to the oceans by rivers and wind.12

Terrigenous clastic sedimentary rocks are a major category of sedimentary rocks, composed of detrital fragments of pre-existing rocks and minerals. They are also known as siliciclastic rocks due to their silica content. These rocks are classified based on the size of their constituent grains, ranging from clay and silt to sand, and even larger fragments like pebbles and boulders. Examples include mudrock, sandstone, conglomerate, and breccia.345

Terrigenous sediments can be transported by turbidity currents, forming deposits called turbidites, which are layered sediments grading from coarser to finer particles. These deposits build deep-sea fans and abyssal cones. Brown clays, primarily of terrigenous origin, are also a common type of deep-sea sediment.2