Discussion on classification and naming scheme of fine-grained sedimentary rocks

PENG Jun,ZENG Yao,YANG Yiming,YU Ledan,XU Tianyu

Table 2 Classification and nomenclature of grain grades (modified according to reference [26])

Grain diameter/mm Clastics in clastic rock Clastics in carbonate rock Crystal grains in carbonate rock Decimal grading scheme 2 geometric progression scheme Larger than 2.0 Larger than 2.0 Conglo- merate Conglomerate debris Conglomerate crystal 0.1-2.0 0.062 5-2.000 0 Sand Arenaceous Sand crystal 0.005-0.1 0.003 9-0.062 5 Silt Powder debris Powder crystal Smaller than 0.005 Smaller than 0.003 9 Mud Mud debris Mud crystal