Grains derived from marine organisms. Qochayx Island, Coos County, Oregon
Biogenic grains in sand include the parts of both marine plants and animals that use calcium carbonate minerals in their bodies. Whole or broken up, their hard body parts contribute to sand. The fragments found in sand reflect the marine diversity of the region. They can include fragments of shells, corals, sea urchin spines and their hard bodies, barnacle plates, bryozoans and more. Some sand samples are completly composed of biogenic grains as in the examples below.
Barnacle plates and blue mussel fragments.
Kaunjou Island, Solomon Islands
Urchin spines plus pink forams
Big Island, Hawaii
Urchin spines, mollusks, green olivine, black basalt
Galway, Carraroe County, Ireland
Coralline algae rods, mollusks
Urchin spines, mollusks, pink forams
Ft. George Island, Florida
“Shell Hash” clam and oyster shell fragments
Barnacle plates and crab claws
Pink and disc-shaped forams, urchin spines, coralline algae
Haean National Park, South Korea
Bryozoan rods showing pores, mollusks fragments