DETERMINING DEPOSITIONAL ENVIRONMENT BY STRATIGRAPHIC SEQUENCING AND FOSSIL ASSEMBLAGE ANALYSES OF THE NAVESINK FORMATION'S EXPOSURES AT BIG BROOK PRESERVE, MONMOUTH COUNTY, NEW JERSEY

The objective of this research project was to examine the results of stratigraphic and fossil assemblage analyses in order to determine the environments in which the Navesink Formation exposed at Big Brook Preserve in Monmouth County, New Jersey was formed. In the studies researched, the percentage of glauconite was determined by collecting multiple vertical samples at invariable intervals from stream level to the surface of the formation. The samples were disaggregated, removing the macrofossil fauna and then were sieved removing the silt and clay. The sand-sized material was dry sieved in order to estimate the weight-percent dissemination. The fractions of heavy minerals were procured from sample splits by use of heavy liquid for dissolution and were classified by x-ray diffraction (Bennington, 2000). The samples examined not only provided the percentages of glauconite, silt and clay but also provided measures of lignite, mica, siderite, pyrite, garnet, chlorapatite, amphibole, phosphate and others such as labradorite and clinopyroxen. The fossil assemblages of which are concentrated into the zones of Belemnitella, Exogyra, Agerostera/Choristothyris and Pycnodonte are each separated within exclusive stratigraphic compositions formed in different benthic environments. The results of glauconite percentage trends upwards, as well as the lucina and cucullea fauna exhibit the conditional environment in a transgressing marine environment.