A sedimentary rock is a lithified deposit of detrital particles such as clay, silt, sand, or gravel; of (bio-)chemical precipitates (including evaporites) and of organic material.
Detrital (or clastic) sedimentary rocks consist of preexisting solid particles that are eroded somewhere, transported (by gravity alone, wind, water, or ice) and deposited. The main detrital minerals are feldspar, quartz, and clay minerals, all of which are stable at low-temperature aqueous conditions; due to the comparative greater resistance of quartz, however, quartz is more common than feldspar. Many minerals common in the continental crust do not (or only rarely) survive the exogenic processes of weathering, erosion, transport, and diagenesis. Thus, many clastic sedimentary rocks are largely made of only few minerals. Accessory minerals are therefore of great interest because they can deliver specific information on provenance, climate and transport.
In chemical sediments, water-soluble...