淤泥是泥土的基本组成成份之一。地质学中，淤泥是介于沙土及黏土之间，主要由石英及长石组成。

维基共享资源中相关的多媒体资源：淤泥

Silt is granular material of a size somewhere between sand and clay, whose mineral origin is quartz and feldspar. Silt may occur as a soil or as sediment mixed in suspension with water (also known as a suspended load) in a body of water such as a river. It may also exist as soil deposited at the bottom of a water body. Silt has a moderate specific area with a typically non-sticky, plastic feel. Silt usually has a floury feel when dry, and a slippery feel when wet. Silt can be visually observed with a hand lens.