Three locations in two South African rivers containing abundant magnetite were surveyed and sampled. Five-fold magnetite enrichments at two sites, but significant enrichment lacking in the third. Flow within the first two sites was maximally constricted; sediment input was matched by output. In the third site, the bar was still migrating toward the bank so that flow was not yet fully constricted; most bar-transported sediment was thus trapped in marginal foresets and not sorted by currents.--Modified journal abstract.

First Page Preview

First page PDF preview
You do not currently have access to this article.