Home Page Science Frontiers

No. 120: Nov-Dec 1998

Issue Contents

Other pages

Other Interesting Sites











Spod Logs

The Black Hills of the Dakotas are composed of Precambrian shists that have been intruded by granite. The Harley Park granite is well known to us all because it has been carved into the monumental visages of four presidents at Mount Rushmore. Nature, too, has expressed herself on a giant scale nearby.

"Around the granite, the shists are host to numerous spectacular pegmatites. These were mined and quarried in the early years of this century for both the large sheets of mica and also the spoduomene, which was a valuable source of lithium. The largest crystals were of the spoduomene, which were found up to 20 m [63 feet] long. Looking like great white tree trunks with two cleavages along their length, they were affectionately known as spod logs."

(Waltham, Tony; "Spod Logs," Geology Today, 13:207, 1997.)

Comment. Any crystal 63 feet long is worthy of mention in this newsletter!

From Science Frontiers #120, NOV-DEC 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