B5 Sedimentary Petrology of the Cretaceous Sediments of Northern
Delaware in Relation to Paleogeographic Problems The non-marine
Cretaceous sediments of northern Delaware older than the Magothy
formation cannot be divided accurately into formations or
mappable geologic units because their lithologic characteristics
are very similar. However, two heavy mineral zones can be
distinguished in these deposits: a lower staurolite-kyanite-
tourmaline-zircon zone, and an upper tourmaline-zircon-rutile
zone with abundant alterites. They have been named the Patuxent
zone and the Patapsco-Raritan zone respectively. The Magothy
formation is characterized by abundant staurolite and also
contains significant amounts of tourmaline. The marine Upper
Cretaceous deposits have a greater variety of heavy minerals
than the underlying non-marine sediments. They contain abundant
epidote; chloritoid, first appearing at the base of the
Merchantville formation, is persistently present. Garnet is
found in the Merchantville and the Mount