Tuesday, 5 May 2009
Unchanged for 2 million years, an area of ground in the Negev desert has been found by researchers to be the oldest unchanged area of earth. The NY Daily News reports:
If only they could pave highways with this stuff.
Scientists have discovered a patch of the earth's surface that remains virtually the same as it was 1.8 million years ago - and it looks pretty good for its age.
Researchers are calling an expanse of "desert pavement" in Israel's Negev Desert the oldest continuous surface on earth, the current issue of the journal GSA Bulletin reports.
Most of the earth's surface is constantly, if not always rapidly, evolving - through erosion, volcanic activity, the movement of tectonic plates underneath the earth's surface, and just plain old weather.
But an unusual feature of deserts, which have little tectonic activity and terrain that's resistant to their hot, dry weather, is that large surfaces of ground can remain virtually the same for millions of years.
"This is something we were not sure about until now," Ari Matmon, who headed up the study, told LiveScience.com.
Matmon's team from the Hebrew University of Jerusalem confirmed the age of the terrain by measuring concentrations of an isotope found only on the earth's surface. It also indicates how long the surface has been exposed to the elements.
The patch of terrain is four times older that the next oldest areas of desert, in Nevada, LiveScience.com reported, though there are individual rocks much older than any patch of ground. Those remain the oldest objects on earth.