Biogenic Sands

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.

Auke Recreation Area
Juneau, Alaska

Barnacle plates and blue mussel fragments.
Morovo Lagoon
Kaunjou Island, Solomon Islands

Urchin spines plus pink forams
Puako Beach
Big Island, Hawaii

Urchin spines, mollusks, green olivine, black basalt
Coral Strand
Galway, Carraroe County, Ireland

Coralline algae rods, mollusks
Taga'chang Beach
Yona, Guam

Urchin spines, mollusks, pink forams
Huguenot Memorial Park
Ft. George Island, Florida

“Shell Hash” clam and oyster shell fragments
Kemah Boardwalk,
Kemah, Texas

Barnacle plates and crab claws
Horseshoe Bay
Southampton, Bermuda

Pink and disc-shaped forams, urchin spines, coralline algae
Hakampo Beach
Haean National Park, South Korea

Bryozoan rods showing pores, mollusks fragments
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