Heavy-mineral transport and deposition in a gravel-bed river was studied by placing 40,000 kg of heavy minerals at the upstream end of a meander-bend channel prior to a flood. During a subsequent flood, redeposition of the tracer heavy minerals was limited to the meander-bend part of the channel. High concentrations of heavy minerals formed on the point-bar face and in particular downstream of the point-bar apex. Zones of flow separation in the lee of boulders and cobbles are favorable sites for heavy-mineral concentration. Low heavy-mineral concentrations were formed in the thalweg and on the outer bank of the meander bend despite high bed roughness there. At the downstream end of the meander bend a swamp effectively filtered out heavy minerals from suspension.

First Page Preview

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