Terrigenous Organic Matter in Sediments of the St. Lawrence Estuary and the Saguenay Fjord

Abstract

The proportion of land-derived organic matter in sediments of the upper St. Lawrence Estuary is unexpectedly low. In the Saguenay Fjord and the lower estuary, high organic carbon to nitrogen ratios and the presence of lignin indicate a substantial contribution of organic matter from terrestrial sources. The proportion of terrigenous organic matter decreases rapidly thereafter, approaching levels typical of marine sediments in the open Gulf. Key words: Organic matter, sediments, carbon to nitrogen ratio, lignin, St. Lawrence Estuary, Saguenay Fjord