Meteorites or Springs as Geological Agents?

Abstract

DOUGLAS JOHNSON'S recent death is mourned by a wide circle of friends and admirers on both sides of the Atlantic. Johnson delighted in interpretation of scenery and showed to equal advantage in choice of subject, plan of attack and clarity of exposition. In his latest monograph¹, which includes forty-six illustrations, mostly air-photographs, he dealt with a problematical erosion form represented by tens of thousands of parallel, oval, marshy hollows pitting the coastal plain of America. The area affected measures some 25,000 square miles, and ranges through South Carolina into neighbouring States. Here marshes of any shape are commonly called 'bays', perhaps, it has been suggested, because bay trees flourish in them. This local practice accounts for the title selected by Johnson for his book, "The Origin of the Carolina Bays". Johnson alternatively speaks of the oval hollows as craters. They are shallow basins, measuring anything from a few hundred feet up to four miles in length, and averaging about 50 ft. in depth, when allowance is made for partial infilling with peaty silt. Usually they are more or less completely encompassed with white sandy rims.