Global cycles of life-giving elements
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.
Topic: Earth Science
Subtopic: Earth Structure
Keywords: Ocean, Hydrology, Carbon cycle (Biogeochemistry)
This coal contains metamorphosed organic matter (carbon) and brassy-colored iron sulfide minerals formed from decaying plants.
This calcium carbonate limestone is comprised of a group of fossil shells cemented by bituminous (organic carbon-rich) calcite.
This sample is from the chalk beds of southern England.
This sample of limestone is composed of carbonate minerals, and formed in a shallow ocean.
Living organisms, including trees, tie up only a small fraction of the Earth’s carbon, but that carbon moves rapidly soils (the largest reservoir for carbon on land) and the atmosphere.
Deep burial of calcium carbonate-bearing rocks results in metamorphism, or transformation, of limestone to marble.