In the deepest parts of the ocean, below 4,000 meters, the combination of high pressure and low temperature creates conditions that dissolve calcium carbonate, the material marine animals use to make their shells. In the deepest parts of the ocean, below 4,000 meters, the combination of high pressure and low temperature creates conditions that dissolve calcium carbonate, the material marine animals use to make their shells. Earth Sciences Environment Phys.org – latest science and technology news stories