| Popis: |
There has been much work done on metal trends in salt marsh sediment sequences, but relatively little on radiometric dating of these same deposits. Using the example of the Severn Estuary, southwest England, both of these techniques are used to demonstrate how temporal metal pollution trends can be spatially correlated throughout the estuary to provide a series of dated time planes representing 1840, 1936, 1951, and 1958. Using these time planes a stratigraphic correlation of the cyclic saltmarshes of the system is demonstrated. Using this correlation, it has been shown how vertical marsh accretion rates vary in the Severn Estuary with respect to both time and space, and that the elevation and spatial position of the marsh surface is of fundamental importance when considering vertical accretion rates. From this, it becomes evident that the potential misconceptions which can arise when quoting single estimates of accretion for an estuary can be very misleading in an understanding of macro-scale estuarine processes |
Full Text from ScienceDirect