ABSTRACT: Stratigraphic Analysis of the St. Jones Estuary

DWRC 2001 – 2002 Intern: Lindsay Scanlon

Project Advisor: Dr. Ronald Martin

Estuaries are affected by natural and anthropogenic changes in their associated environmental settings. To fully understand the extent to which current depositional processes result from either factor, the historical stratigraphic record must first be explored. Importantly, the long-term record documents historical trends in depositional environments. This project entails a study of the stratigraphic record for the St. Jones Estuary within the Delaware National Estuarine Research Reserve (DNERR), with the hopes of providing information for future studies concerning sea -level rise or other stresses that have a potentially averse effect on the estuary. Methods involving the use of three inch, dutch-auger core devices within the St. Jones marsh accomplish the field aspect of this study, and the first step towards arriving at a detailed stratigraphic record for the area. Careful, field documentation of the meter-long sections of these cores provides the basis for subsequent construction of vertical core columns. These columns are constructed according each layer’s respective lithologies and inferred depositional environment. A GPS locating system records the location of each core recovered out in the field, allowing for the possible correlation of the cores later on in the lab. The field and lab portions of this study result in stratigraphic columns that summarize the depositional history for various locations within the St. Jones estuary. This information provides useful information for future studies addressing the present condition of the estuary system since it provides a context for those current depositional environments.