کد خبر: 136785تاریخ: 1394/11/26 15:17
Rocks can help us learn about past climates
Rocks can help us learn about past climates
Scientists have found a new way to tease out signals about Earth's climatic past from soil deposits on gravel and pebbles, adding an unprecedented level of detail to the existing paleoclimate record and revealing a time in North America's past when summers were wetter than normal.


A research team led by soil scientists at the University of California, Berkeley, obtained data about precipitation and temperature in North America spanning the past 120,000 years, which covers glacial and interglacial periods during the Pleistocene Epoch. They did this at thousand-year resolutions ― a blink of an eye in geologic terms ― through a microanalysis of the carbonate deposits that formed growth rings around rocks, some measuring just three millimeters thick, reported.

"The cool thing that this study reveals is that within soil ― an unlikely reservoir given how 'messy' most people think it is ― there is a mineral that accumulates steadily and creates some of the most detailed information to date on the Earth's past climates," said senior author Ronald Amundson, a UC Berkeley professor of environmental science, policy and management.

The study, published in the Proceedings of the National Academy of Sciences, shows the rich potential held within soil deposits known as 'pedothems', which form growth rings on rocks. The samples used in the study came from Wyoming's Wind River Basin.

Because these soil deposits, commonly found in drylands all over the world, can provide a rich source of data for paleoclimatologists

لینک مطلب:
Page Generated in 0/0042 sec