Geosciences

GEOSCIENCES

BY PETER J. SMITH
Department of Earth Sciences
Open University
Milton Keynes, U.K.

" A new type of carbonate-platform margin has been recognized in the Gulf of Mexico and Caribbean regions. Named a “scalloped margin,” it comprises a series of irregular embayments, convex on the platform side, and is thought to be largely an erosional feature produced by large-scale failure triggered by earthquakes or resulting from undercutting by dissolution.

H.T. Mullins, A.C. Hine, “Scalloped bank margins: Beginning of the end for carbonate platforms?,” Geology, 17,30-3, January 1989. (Syracuse University, Syracuse, N.Y; University of South Florida, St. Petersburg)

The angular momentum and orbital characteristics of the Earthmoon system, and the chemical and density differences between .the Earth and the moon, can all be explained on the assumption that the moon formed from the mantle of a single body (slightly larger than Mars) that collided with the Earth.

H.E. Newsom,...