Many large porous sand bodies formed in open reaches of ancient continental shelves and slopes should be recognizable in the stratigraphic record; they have considerable economic and academic significance. The present paper is concerned with modern analogues in the shallow seas around western Europe. The new deposits and their depositional environment allow the depositional environment of the ancient ones to be interpreted more realistically. In addition to the extensive but thin sand sheets, there are many modern sand bodies that are isolated from one another. They can be tens of miles in length, a few miles wide, and more than 200 ft thick. They may occur singly or in extensive groups and are parallel with or transverse to the currents that formed them. Some of the larg st ones were made by the Mediterranean undercurrent on the continental slope of the Gulf of Cadiz. Others, of similar size on the continental shelf, are attributed to a tidal-current origin. Modern tidal flow around the British Isles also is responsible for such sand bodies, as well as a variety of other forms. Only semiunidirectional currents seem to be depositing sand in the western approaches to the Baltic.

End_of_Article - Last_Page 807------------