Sedimentary Petrology Of The Cretaceous Sediments Of Northern Delaware In Relation To Paleogeographic Problems
Date
1955-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Newark, DE: Delaware Geological Survey, University of Delaware
Abstract
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 Laurel-Navesink formations. The heavy mineral composition of the
Cretaceous sediments is shown in table IV.
Description
This report has 2 plates listed separately.
Keywords
Sedimentary, Petrology, Cretaceous, Paleogeographic