Elemental Composition of Peats Ashed at Low Temperatures (95^°C), from the Fraser Delta, British Columbia, Canada

Abstract

The elemental distribution in peat deposits from Fraser delta, British Columbia, Canada were examined on peat ashed at low temperature (90°C) using INAA, DCP, andAA. Chlorine, B, Br, Mo, Na, S, and U are sensitive indicators of the depositional environment of these peats. The distribution of elements is related to water salinity. High concentrations of Cl and Na are encountered in samples deposited in brackish water environment and in the contact between the peat and the sea water. The concentration of Cl and Na decrease with decreasing distance from the contact with sea water. Silicon has the lowest concentration on the top of the fresh water peat and the highest on or near the top of brackish water peat. The concentration of the “authigenic uranium” in peats appears to be related to water salinity. The highest values are found in brackish water peat, indicating that uranium is possibly concentrated by its interaction with salt and carbonates. Compared to the Clark value, the only elements enriched in the peals ashes are: As, Br, Mo, Sb, and Se white Ca, Mg. and Mn are depleted. The ternary diagram of La-Th-Sc, which is associated with the detrital minerals, points to a uniform source for the minerals encountered in these peats.