The alluvial fringes of the Somerset Levels
Using core lithology and palaeoecological analyses, the vegetational and landscape development and local hydrological conditions since c. 6000 BP in two areas of the Somerset Levels has been studied. Focusing on the former characteristics of the river Brue, the floodplain upstream from Glastonbury and the area near Panborough Gap in Wedmore Ridge were investigated. In the latter area a distinct palaeochannel thought to be the prehistoric course of the Brue is present. Both areas show a similar development with saltmarsh and lagoonal environments until 6000 BP, followed by a prolonged period of Alnus - Salix carr and sedge fens. In the Panborough area freshwater deposition was interrupted by distal saltmarsh and lagoon sedimentation between 2900 BP and 2200 BP. This marine incursion caused stagnation of river discharge upstream which led to the growth of Cladium-rich ~tloodinq layers~ in the central raised bog area. After embankment of the rivers in the Middle Ages the changed hydrological conditions caused deposition of the upper floodplain clays. Until medieval embankment and canalisation determined its present day course, the river Brue did not have a fixed course but consisted of several small short-lived
Aalbersberg, Gerard
Palaeoecology; Landscape reconstruction
The alluvial fringes of the Somerset Levels. Using core lithology and palaeoecological analyses, the vegetational and landscape development and local hydrological conditions since c. 6000 BP in two areas of the Somerset Levels has been studied. Focusing on the former characteristics of the river Brue, the floodplain upstream from Glastonbury and the area near Panborough Gap in Wedmore Ridge were investigated. In the latter area a distinct palaeochannel thought to be the prehistoric course of the Brue is present. Both areas show a similar development with saltmarsh and lagoonal environments until 6000 BP, followed by a prolonged period of Alnus - Salix carr and sedge fens. In the Panborough area freshwater deposition was interrupted by distal saltmarsh and lagoon sedimentation between 2900 BP and 2200 BP. This marine incursion caused stagnation of river discharge upstream which led to the growth of Cladium-rich ~tloodinq layers~ in the central raised bog area. After embankment of the rivers in the Middle Ages the changed hydrological conditions caused deposition of the upper floodplain clays. Until medieval embankment and canalisation determined its present day course, the river Brue did not have a fixed course but consisted of several small short-lived
alluvial fringe somerset levels using core palaeoecological analysis vegetational landscape development local hydrological condition since two_area somerset levels study focusing former characteristic river floodplain area near gap ridge investigate latter area distinct think prehistoric course present area show similar development environment follow prolonged period fen area freshwater deposition interrupt marine incursion cause stagnation river lead growth rich central raise bog area river middle_ages change hydrological condition cause deposition upper floodplain clay medieval determine present_day course river fix course consist several_small short_lived