Fossil-filled fossil soil was found

(The soil has formed on the surface of the earth thousands of years ago and is now buried underground found to be very rich in carbon, adding a new dimension to the carbon cycle of Earth.

This finding, published in Nature Geoscience, is an important finding because it shows that deep layers of soil can have long-buried organic carbon stocks that have been through erosion, soup. Agriculture, deforestation, mining and other human activities, contributing to global climate change.

'There is an infinite amount of carbon in the ground where it has not been evaluated , ' said Erika Marin-Spiotta, an assistant professor of geography at the University of Wisconsin Madison and the lead author of the study. 'It is thought that there is very little carbon in the deeper soil. Most studies only performed on the top 30cm topsoil. Our research is showing that it is possible that we have underestimated the amount of carbon in the soil. '

The soil studied by Marin-Spiotta and her colleagues, known as Brady Land , was formed about 15,000 and 13,500 years ago in what is now Nebraska, Kansas and other parts of the Great Plains. This soil is located at a depth of 6.5m below the present surface and buried due to the accumulation of large amounts of dust called loess that began about 10,000 years ago, when glaciers covered much of the North America began to withdraw.

The area where Brady land formed was not frozen, but underwent radical transformation when the retreat of the glacier at the Northern Hemisphere caused a sudden climate change, including changes in vegetation and a forest fire regime, contribute to carbon sequestration when soil is quickly buried by loess accumulation.

' Most carbon (in Brady soil) is unburnt carbon or black carbon' , Marin-Spiotta, the head of the research team, used a variety of new analytical methods, including spectral analysis and Isotope analysis for soil analysis and chemical composition of soil emphasized. 'It seems that the number of fires is amazingly high'.

The research team led by Marin-Spiotta also discovered organic matter from ancient plants, thanks to being covered by thick loess dust , was not completely decomposed. Such burial helps to isolate the soil from biological processes that these biological processes often break down the carbon in the soil.

According to UW-Madison geography professor, such buried soils are not unique in Great Plain but occur all over the globe.

Research shows that fossil organic carbon in buried soil is common, and as people increasingly influence the landscape through a series of activities, will contribute to the potential of climate change when carbon Organic kept in dry and semi-arid environments are returned to the environment.

Carbon elements come in many forms and cycles through the environment - soil, sea and air - just like water goes through many forms and through cycles through soil, oceans and air. Scientists have long known about the ability to store carbon in the soil, the ability to absorb carbon, and carbon in the soil that can be released into the atmosphere through biodegradation.

Deeply buried soil is studied by Marin-Spiotta, Mason and their colleagues, a 1-meter-thick black strip of land located at the present surface depth, a storage environment in the past, researchers explain. This soil layer provides a quick picture of an environment that undergoes great changes leading to a climate change. The withdrawal of glaciers signaled a warm earth, and seemed to contribute to a changing environment by establishing a period of increased forest fires.

'The Earth has warmed up during the period Brady formed , ' Mason said. 'Warm season grasses have increased and their spread on the ground is almost certainly related to rising temperatures.'

The retreat of the glaciers was also established in the movement of an era when the loess began covering large chunks of the ancient ground. Basically, dust - characteristic of loess - can be more than 50m thick in parts of the Midwestern United States and parts of China. It covers large areas, including hundreds of square kilometers of sediment.