A Comparison of Sediments from Above and Below a Tidal Restriction in the Back River Creek Marsh, Woolwich, ME

• Main Author: Snow, Carolyn Ruth
• Format: Text
• Language: unknown
• Published: SCARAB 2021
• Subjects: Salt Marsh; Spartina; tidal; Back River
• Online Access: https://scarab.bates.edu/geology_theses/54; https://scarab.bates.edu/cgi/viewcontent.cgi?article=1055&context=geology_theses

This study examines the geologic and anthropogenic history of the Back River Creek Marsh (BRCM) in Woolwich, ME through a comparison of sediments from above and below Route 1. Using a combination of geochemical and visual analyses, observations about the BRCM reveal that the origins of the marsh may be more complex than initial theories suggested. Using a Pb age model to assign dates to the sediments at depth, it has been determined that the area has been a brackish or freshwater marsh since the late 1700s. The δ13C values from several cores across the marsh range between -24‰ and -30‰, falling well within the typical C3 plant range, thus indicating a fairly fresh marsh setting. The initial hypothesis was that the BRCM was originally a salt marsh that had become restricted by a dike and Route 1, but the geochemical analyses show little evidence suggesting a purely saltwater origin. This study has resulted in more questions about the BRCM, paving the way for further research to understand the complexities of its history.