How the grains were formed – beach (ocean) versus river sand, river sand versus clay?
• Grain size and pattern arrangement: the actual size of the grain has no effect, but the arrangement pattern has a large effect. • Shape of the grains — grains of high sphericity tend to pack with minimum pore space as angularity increases, pore space. As volume increases pore space volume usually increases. • Sorting of the grains — uniformity of size has an effect; the more uniform the size, the greater volume of voids. Mixing different sizes tends to decrease total volume of void space. • Subsequent action to the sediments (compaction) — compaction decreases volume of void spaces. Compaction of sand is less dramatic than that of clay. • How the grains were formed — for example, beach sand has rounded grains while river sand is angular so the latter increases pore space. River sand is granular while clay grains form parallel plates; the latter has greater porosity, but sand has greater permeability. Question: In the answer to Question 1 above, we said that the arrangement patter