redeposition

Redeosition is the process by which material that has been transported away is deposited again at a different location. It can involve sediment grains moved by water, wind, ice, or gravity, and is common in many geological settings. Redeposition often occurs when transporting forces decrease, when chemical conditions change, or when the energy of the system fluctuates, causing suspended or entrained material to settle out anew. The result is a reworked or secondary deposit that may overlie or mix with the original material.

In sedimentology and stratigraphy, redeposition refers to sediments that are eroded from one place and deposited elsewhere, producing features such as reworked sands, lag gravels, or turbidites. Reworked material can have a different mix of grain sizes, roundness, or mineralogy than the source material. This process can complicate interpretations of ancient environments, as redeposited sediments may obscure primary deposition signals.

In ore genesis and mining contexts, redeposition describes the precipitation or replacement of minerals from fluids after their transport, often triggered by changes in temperature, pressure, or chemical conditions. Redeposited ore minerals commonly form veins, stockworks, or disseminations distinct from primary depositional textures. The study of redeposition helps distinguish between early, primary minerals and later accretions, informing exploration models.

Indicators of redeposition include overprinting cross-cutting relationships, immature or mixed sediment fabrics, abrasion of clasts, and the presence of mineral assemblages that require different conditions than the surrounding rock. Redeposition is a key concept for understanding sedimentary history and the evolution of mineral deposits.