麻豆传媒

听

The foraminiferal assemblages present along two Kingsport marsh surface transects were delineated into zones with respect to vertical elevation above mean sea level (a.m.s.l.), and salinities. The highest vertical zonation, Zone I, is distinguished at its upper limit, Higher High Water (HHW), by the disappearance of foraminifera in the sediments, while the zone itself is defined by the dominance of Trochammina inflata. The horizontal range of this zone is approximately 20 meters, while the vertical range is approximately 1 meter, from 650-750 cm above mean sea level (a.m.s.l.). Zone II, the middle and lower marsh zone, is distinguished at its lower margin by the sharp decline of agglutinated species and the increase of calcareous estuarine species. This zone is defined by the dominance of both Miliammina fusca and T. inflata, with significant numbers of Tiphotrocha comprimata and increasing occurrences of calcareous estuarine specimens in the lower marsh.

Using Carbon14 dating, marsh foraminiferal zonations in subsurface sediment, and tidal amplifications calculated for four sea level curves, actual relative sea level rise in the Bay of Fundy were determined. These figures range from 16 cm/100 years at Kingsport to 25.6 cm/100 years at Granville Ferry marsh.

Keywords:
Pages: 57
Supervisors:听 Franco Medioli / David Scott