Glaciers reached Cape Cod, Massachusetts, in the most recent ice age about 20,000 years ago. But much harsher ice ages hit the Earth in an ancient geological interval known as "the Cryogenian Period" between 750 and 600 million years ago. A team of geologists from China and the United States now report evidence of at least three ice ages during that ancient time.
Shown is a glacial cobble from the Nantuo Formation, Guizhou Province, South China. Grooved scratch marks on this cobble were formed when it was frozen in a moving glacier and ground against the underlying pavement of the glacial valley.
"The Cryogenian Period is characterized by some of the worst glaciations in earth history. But the available age constraints are so few that geoscientists dont even know how many glaciations occurred in the Cryogenian. Now, we believe we have evidence that there were at least three Cryogenian glaciations, and there may have been more," says Shuhai Xiao of Virginia Techs Department of Geosciences.
Chuanming Zhou, a Virginia Tech geosciences post-doctoral associate, along with Xiao, Robert Tucker and Zhanxiong Peng of the Department of Earth and Planetary Sciences at Washington University of St. Louis, and Xunlai Yuan and Zhe Chen of Nanjing Institute of Geology and Paleontology, are co-authors of "New constraints on the ages of Neoproterozoic glaciations in South China," the cover story in the May 2004 issue Geology, the journal of the Geological Society of America.
NASA looks to solar eclipse to help understand Earth's energy system
21.07.2017 | NASA/Goddard Space Flight Center
Scientists shed light on carbon's descent into the deep Earth
19.07.2017 | European Synchrotron Radiation Facility
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
21.07.2017 | Earth Sciences
21.07.2017 | Power and Electrical Engineering
21.07.2017 | Physics and Astronomy