Udden and Wentworth's research on this type of substance yielded their namesake grain size scale, which gives the scientific 
Udden and Wentworth's research on this type of substance yielded their namesake grain size scale, which gives the scientific definitions of terms like "silt" and "clay." Biochemical examples of this type can include aragonite or calcite. The majority of clastic rocks are of this rock type, and most of these are clastic. Subtypes of this with large grains include conglomerates, and it is found in layers by age known as strata. Examples of this rock type, produced by compaction of particulate matter, include chalk, limestone, sandstone, and shale. For 10 points, identify this type of rock which is distinct from metamorphic and igneous.
Udden and Wentworth's research on this type of substance yielded their namesake grain size scale, which gives the scientific definitions of terms like "silt" and "clay."
sedimentary rocks [prompt "sediment" until "clastic" is read; prompt "rock" throughout; why not?]