Rates of tidal sedimentation from records of industrial pollution and environmental magnetism: The Tees estuary, north-east England

摘要

The geochemical and magnetic properties of four sediment cores from Greatham Creek in the Tees estuary, north-east England, provide a record of industrial pollution in the intertidal zone. The peak magnetic concentrations, as interpreted from down-core profiles of chi, SIRM, chi(ARM), and Soft magnetisation, provide a rapid and non-destructive proxy for geochemical analyses. In the absence of variation in grain size or post-depositional migration of sediment pollution, differences in the depth of synchronous peak metal and magnetic concentrations between cores can be attributed to the period and frequency of tidal inundation and, hence, accretion rate. Peak Pb and Zn concentrations can be related to the maximum influx from mining activity in the Tees catchment c. AD 1880 or to industrial activity within the Tees estuary during the 20th Century. The former provides rates of tidal sedimentation of approximately 1, 2, 3 and c. 10 mm yr(-1) for the upper saltmarsh, the lower saltmarsh, the mudflats and a tidal sandflat, respectively, whilst the latter gives corresponding accretion rates of 4, 10, 12 and c. 25 mm yr(-1). References: 66