SALINITY OF MARSHES ALONG THE JAMES BAY COAST, ONTARIO, CANADA

James Bay lowland in Ontario is occupied by one of the most extensive stretches of marshes in North America. The salinities of tide water and sediments from the northern and the southern sectors of the coastal marshes are compared. The distribution of salt is affected by different processes at these two sites. In the north, Bay water of relatively high salinity is introduced to the marsh by tides, as is generally found in coastal marshes elsewhere. The tidewater in southern James Bay has low salinity and the salt in the marsh is released by molecular diffusion from relict salt deposited with the post-glacial Tyrrell sea sediments. This study demonstrates that the salt in coastal marshes may be introduced by different processes and from different sources.