Plunge pool softer or fractured rock has been eroded back to a knickpoint, water continues to bombard its base. Because this rock is often less resistant than overlying strata, the water from the higher elevation continues eroding downward until an equilibrium is achieved. A somewhat similar bowl-shaped feature developed by flowing water, as opposed to falling water, is known as a scour hole. These occur both naturally and as a result of bridge building. Plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It
Chute (racecourse) (grass) course inside of the main (dirt) track, most commonly measuring . This turf course will often be equipped with a chute of its own, extending diagonally from the stretch, to permit turf races to be run at the distance of . This diagonal chute can either consist of a more-or-less straight line, or may curve significantly, in a counterclockwise direction. In 2006 two tracks — Monmouth Park and Hollywood Park Racetrack — added a chute extending diagonally from the backstretch, to permit races at furlongs and 6 furlongs, respectively (the corresponding circumferences of these two tracks' turf courses being