A paleoecological investigation into the post-glacial history of Delta Marsh, Manitoba

Abstract

The project provides information on the ecological history of the Delta Marsh as part of an ongoing study of the marsh ecosystem at the University of Manitoba. Three cores were taken from neighbouring sites in Cadham Bay, a large central bay in a marsh complex. Their lengths were: Core B, 2.19 m; Core A, 3.85 m; and Core C, 8.3 m. Core A was analyzed for sediment, pollen, seeds and selected invertebrate macrofossils, Core B for sediment and pollen, and Core C only for stratigraphy. Sediment type was analyzed to provide information to elucidate trends indicated by the distribution of seeds, selected invertebrate macrofossils and pollen. Fossils were well represented in the upper portion of the cores, but their paucity below the 1 m depth suggests that marsh conditions did not exist when the sediments below this level were being deposited. The cores were divided into six zones based upon seed composition and density. The calcareous silty clay of zone 1 (385-115 cm in Core A) contains a few Bryozoa and scattered ostracods and molluscs, suggesting that relatively deep water conditions prevailed during its deposition...