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No. 118: Jul-Aug 1998

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The Mysterious Terras Pretas

Most of the lush jungles of tropical South America grow on a very thin layer of soil that is continuously regenerated by decaying vegetation. Deforest the jungle and the agricultural potential is about that of a your nearest Interstate highway. But the so-called "terras pretas" are curious exceptions. Spotted along Brazil's Aripuana River are small areas of deep, black earth that are from 7 to 17 feet deep. These are the "terras pretas" or "black earths." Scientists believe that these fabulously productive "islands" in the sea of otherwise poor soil were developed by native peoples about 10,000 years ago. No one knows how these ancient farmers made the terras pretas. The slash-and-burn farming of the present inhabitants is primitive in comparison.

(Anonymous; "Fertile Soil of Ancient Tribes Poses Puzzle," Columbus Dispatch, January 11, 1998. (Cr. J. Fry via COUD-I)

From Science Frontiers #118, JUL-AUG 1998. 1998-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987