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Full-Text Articles in Earth Sciences
The Effects Of Dissolution On The Silicon And Oxygen Isotope Compositions Of Silica Phytoliths, Andrea Prentice
The Effects Of Dissolution On The Silicon And Oxygen Isotope Compositions Of Silica Phytoliths, Andrea Prentice
Electronic Thesis and Dissertation Repository
The δ30Si and δ18O values of silica phytoliths have applications for reconstructing paleoenvironmental conditions. This study examines the effect of partial dissolution and burning of phytoliths on their isotopic compositions, dissolution behaviour, and physical characteristics (specific surface area, mean particle size, and visual appearance) and discusses problems with the use of phytolith δ18O and δ30Si values that have been modified in soils in paleoclimate reconstruction. Dissolution experiments were conducted in batch reactors under a range of pH (4-10) and temperature (4-44˚C) conditions. The δ18O and δ30Si values of …
Peatland-Stream Hydrological And Biogeochemical Connectivity In The James Bay Lowland, Ontario, Meghan Kline
Peatland-Stream Hydrological And Biogeochemical Connectivity In The James Bay Lowland, Ontario, Meghan Kline
Electronic Thesis and Dissertation Repository
The Hudson-James Bay Lowlands are the second largest peatland dominated area on the planet, and are expected to be particularly vulnerable to future climate change. Changes in climate will affect peatland hydrology and biogeochemistry, impacting the aquatic ecosystems this region supports, however there is limited information about the hydrology and biogeochemistry of this landscape under current conditions. This thesis focuses on assessing the nature of hydrological and biogeochemical connectivity between a fen and 2nd order channel in the Central James Bay Lowland, Ontario. Specifically the study focuses on the role of preferential hydrological flowpaths in the riparian area, such …
Peat As An Archive Of Remote Mercury Deposition In The Hudson Bay Lowlands, Ontario, Canada, William James Goacher
Peat As An Archive Of Remote Mercury Deposition In The Hudson Bay Lowlands, Ontario, Canada, William James Goacher
Electronic Thesis and Dissertation Repository
Peat from the Hudson Bay Lowlands (HBL) in Northern Ontario, Canada was used to reconstruct historical accumulation of mercury (Hg) over more than 7000 years before present. Nine cores, many with previously published paleoclimate studies, were analyzed for Hg and accumulation rates were calculated. Anthropogenic Hg enrichment factors were calculated based on accumulation rates. A more exclusive calculation of the anthropogenic enrichment factor corroborates modelling efforts that have suggested re-cycling legacy Hg is a much greater contributor to present day deposition than previously thought, but not prior to ~500 cal yrs BP. An older pre-industrial record provides a better background …