What is a pelite in geology ?

In its current meaning, a pelite is a very fine-grained, loose or consolidated detrital sedimentary rock. Its mineralogical composition is dominated by clay minerals (30 to 75% of the rock); to which are added variable quantities of quartz and micas, rare feldspars and sometimes an organic component (limestone tests). Pelites abound in detrital formations, where they alternate with coarser arenaceous beds.