Finding the Origin of Sediments along the Northern New Jersey Watersheds by Analyzing the Rare Trace Elements and Surrounding Land Use

Lizzie M. Starks¹, Anthony Torres², and Gregory A. Pope^3
1Jackson State University, Jackson, MS
²Bergen Community College, Paramus, NJ
³Montclair State University, Montclair, NJ

The watersheds of Northwest New Jersey span a transition between old urban centers to (now) forested Appalachian ridges, with intervening agriculture, suburban growth, small scale industry, and small-moderate scale hard-rock mining. The region encapsulates human impact from the Colonial Era to present. For the watersheds, human impacts are evident in the sediment storage of streams, their floodplains, and active and relict impoundments. We approach an assessment of human impact and environmental change by means of sourcing the sediment through trace element analysis. Samples- of stream bed, stream bank, and floodplain sediments, and urban and upland soils were obtained from locations in the Flat Brook, Rockaway River, Papakating Stream, and Walkill River watersheds in Sussex and Morris counties in New Jersey. Trace elements content was determined using inductively coupled plasma mass spectrometry (ICP_MS), while Cs-137 and Pb-210 activities for age dating were assessed by a Canberra broad band gamma detector. Elements such as Zr and W successfully distinguish sediment sources (i.e. floodplain, bank, upland), while elements such as V, Cr, and Sr are significant in distinguishing source land use. Related to sediment sourcing, the field data rapid geomorphic assessment (RGA) also correlates to the presence of certain trace elements. Notable discoveries include elevated trace elements in some urban streams, with possible correlation to small-scale industrial and mining activities of the 19^th and 20^th centuries.

AAPG Search and Discovery Article #90181©2013 AAPG/SEG Rocky Mountain Rendezvous, University of Wyoming, Laramie, Wyoming, September 27-30, 2013