A cubic meter of marine limestone or sediment may contain as many as four million Foram shells. Foram shells cover a larger portion of the Earth's surface than any other individual material. Geologists drilling for oil and gas use fossil Forams as guides to individual layers in the Earth's crust. Forams are excellent index fossils since different species can be correlated with sedimentary layers dating back 500 million years. Forams live in coastal marshes, lagoons, estuaries, and all open-ocean waters including the shelf, slope, rise, abyss, trench, and ridge zones.
Forams are also pollution indicators in coastal waters.
Most Foram shells have chambers arranged in spiral or other patterns. Back to home.