Home Page Science Frontiers

No. 43: Jan-Feb 1986

Issue Contents

Other pages

Other Interesting Sites











Everglades astrobleme?

Astrobleme means "star wound," and the southern tip of Florida seems to have been wounded by an asteroid or some other celestial projectile. At a recent meeting of the Geological Society of America, E.J. Petuch proposed that the Everglades region received a direct hit from an asteroid about 36 million years ago.

The Everglades region is a swampy, forested area surrounded by an oval-shaped system of ridges. Geologists usually maintain that the Everglades represent a collapse feature caused by groundwater dissolving away limestone. (Buildings and cars seem to be swallowed fairly regularly by Florida sinkholes.) Petuch disagrees with the collapse theory and points to the following evidence for an impact origin:

1. The presence of a strong positive magnetic anomaly; 2. Eocene formations, 40 million years old, are missing over the southern Everglades; 3. A network of fractures pervades rock layers older than Eocene; 4. High iridium concentrations, probably of extraterrestrial origin, exist at the Eocene-Oligocene boundary on nearby Barbados; and 5. The oval reef structure that seems to have grown around the impact area as sealevels rose.

Some geologists do not concur with the asteroid theory, but they are all reviewing Florida's geological history in a new light.

(Weisburd, S.; "Asteroid Origin of the Everglades?" Science News, 128:294, 1985.)

Reference. Very large craters and astroblemes are cataloged in ETC in out catalog: Carolina Bays, Mima Mounds, which is described here.

Asteroid's footprint near Florida Everglades Time, of December 9, 1985, has a nice map of the asteroid's "footprint", but copyright laws prevent us from using it; so we've made our own. The black circle is the collapsed basin surrounding the impact point. The elliptical coral reef is tangent to the southern rim of the collapse basin and runs northwest through the tomatoes, loops around Lake Okeechobee between the peas and lima beans.

From Science Frontiers #43, JAN-FEB 1986. 1986-2000 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