Definitions for "RIFFLES"
Keywords:  sluice, rocker, nuggets, zig, zag
On the bottom of a sluice, grooves to trap and hold nuggets.
The wooden ribs or slats placed on the bottom of rockers, long toms and sluice boxes to capture the heavy gold particles while the lighter material was washed away. Sometimes mercury was placed at the riffles to help collect the gold on its way through the box.
small ridges in the bottom of a sluice box that catch gold in sand and gravel.
A characteristic of moving water that indicates where brown trout are likely to be found. Riffles are comprised of fast, shallow water running over gravel or small racks that are often found where the water widens.
shallow areas in a stream where water flows swiftly over gravel and rock
Areas of a stream or river characterized by a rocky substrate and turbulent, fast-moving, shallow water.