Global cycles of life-giving elements

Part of Hall of Planet Earth.

Global Cycles of Life-Giving Elements AMNH/R.Mickens

Elements that sustain life stay in the Earth’s reservoirs for different lengths of time. Carbon in the form of coal or carbonate rocks may remain in the solid Earth for millions of years, but as carbon dioxide it stays in the atmosphere for only a few years. The amount of material transferred between reservoirs can be enormous. The uppermost meter of the entire ocean evaporates to the atmosphere every year, to be returned as rain or snow. This transfer is one of the most important factors controlling climate.

In This Section

Exhibit Coal This coal contains metamorphosed organic matter and brassy-colored iron sulfide minerals formed from decaying plants. Exhibit Coquina This calcium carbonate limestone is comprised of a group of fossil shells cemented by bituminous calcite. Exhibit Chalk This sample is from the chalk beds of southern England. Exhibit Limestone (Fossiliferous) This sample of limestone is composed of carbonate minerals, and formed in a shallow ocean. Exhibit Tree sample Living organisms tie up a small fraction of Earth’s carbon, but that carbon moves rapidly between soils and the atmosphere. Exhibit Marble Deep burial of calcium carbonate-bearing rocks results in metamorphism, or transformation, of limestone to marble.