GEOLOGY

Detailed explanation-1: -Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. When sediments settle out of calmer water, they form horizontal layers.

Detailed explanation-2: -Soil particles vary greatly in size, and soil scientists classify soil particles into sand, silt, and clay. Starting with the finest, clay particles are smaller than 0.002 mm in diameter. Some clay particles are so small that ordinary microscopes do not show them. Silt particles are from 0.002 to 0.05 mm in diameter.

Detailed explanation-3: -Silt consists of grains of particle size ranging from 0.008 to 0.0625 mm (0.0003–0.002 in.). It is intermediate in size between sand and clay. Silt size class ranges from 4.0 to 8.0 (phi). Clay consists of grains of particle size between silt and colloid.

Detailed explanation-4: -Detritus-Latin for “worn down.” Solid rock fragments in sediment are defined by size of the fragments: largest to smallest: BOULDERS, COBBLES, PEBBLES, SAND, SILT, and CLAY.