http://www.dailynews.com/Stories/0,1413,200~20954~1116649,00.html
Friday, January 17, 2003 Orderly rock, soil formations just Mother Nature's little joke By PAUL RECER THE ASSOCIATED PRESS WASHINGTON -- Dramatic circles of rocks or stripes of stones precisely aligned on Arctic plains may look like navigation markers for invading aliens, but a scientist says they are just Mother Nature playing games. "When people see these, their first impression is 'Wow! Who did that?' " said Mark Kessler, a University of California-Santa Cruz geologist. "We are just not used to such dramatic self-organization of stones and soil." But in a study in the journal Science, Kessler said the arrangement of the rocks is the work of nature, using long seasons of deep cold and the heaving and contraction of water-logged, frozen soil. He and B.T. Warner of the University of California-San Diego present a mathematical model that explains how such bizarre shapes are built in Arctic soils. The freeze-thaw cycle of the soils, Kessler said, causes the stones to move and forms domains, or separated collections, of soil and rock. In one ratio of soil and rock, on the island of Spitsbergen north of Norway above the Arctic Circle, the ground movement causes the stones to form perfect circles that resemble giant doughnuts. In a dry lake bed in Alaska, a similar movement with different soil-stone ratios concentrates the soil in regular islands, like stepping stones, surrounded neatly by pebble boundaries. Kessler, who specializes in the study of geologic shapes and formations, said the process occurs most often in the Arctic region, but it can also happen in soils on mountainsides that freeze regularly. "The expansion of wet soil during freezing compresses the soil and pushes on the stones," he said. Over time, "the stones move toward stones and the soil toward soil" until the two are separated, forming distinct shapes on the ground. http://seattlepi.nwsource.com/national/104563_science17.shtml http://www.newsday.com/news/politics/wire/sns-ap-natures-fun0117jan16,0,7189628.story?coll=sns-ap-politics-headlines __________________________________________________ Do you Yahoo!? New DSL Internet Access from SBC & Yahoo! http://sbc.yahoo.com ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
