New Limestone

These white plumes of sediment are limey sands moved by ocean currents near the Bahamas. The islands are dry vegetated land that are accumulations of this sand. Limestone forms in one of three different ways that are both chemical and organic. The first way is the accumulation, on the seafloor, of tiny marine organisms that have extracted calcium carbonate from the water to form their shells and hard parts. A second way is the precipitation of CaCO3 as the concentration levels rise because of evaporation and rise in temperature. The tiny crystals precipitate out of the water and sink to the bottom to form a limy mud. A third way is the formation of oolites. Small fragments of shells and tiny grains of CaCO3 are moved and rolled along the seafloor by currents or waves. Successive layers of CaCO3 form around the grains to make a rounded ball-like structure. Although there are no oolitic limestones in Rock Canyon there are many throughout Utah. (Photo by Ken Hamblin)