Blue Tongue of the Ocean #
Crystals of aragonite, a calcium carbonate mineral derived from the shells of single-celled marine organisms, and direct precipitation, form into oolites (small spherical grains of limestone) as the tidal currents swirl back and forth. Lithification of the carbonate sands produces an oolite limestone.
Although the water is warm and clear, corals do not live in these shallows, probably because of the salt content. Though chemically very similar, the rocks resulting from this precipitating process have a quite different origin from those formed from coral reefs.