Wind gap

A drink pass is loud Meyers Lexicon " The lowest point of a two river basins separating mountain pass ". In the German geology of the " Strunk Pass" is additionally characterized by the much stronger " headward erosion " is one of two rivers, where their sources lie on opposite sides of a dividing land survey.

Strunk passports, in English " wind gaps", is available as a special geoarchives on many continents. Erosion processes of two rivers of a region may have resulted in long geological processes to relief developments that can be morphologically characterized as Strunk passports.

Genesis of Strunk passports

If the larger removal rate of a river on one side reduces the catchment area of the river the other hand, this eventually leads to Flussanzapfung on the other side. The tapped flow is deflected it (eg the " Feldberg Danube" ), or it will be shortened and lose at least part of its catchment area; in the latter case is in the residual water erosion valley henceforth only by a smaller waters instead.

Strunk passes in limestone mountains

If, as Flussanzapfung was accelerated by karstification eg in the Swabian Alb, the Dinaric Alps or the Southern Limestone Alps, the valleys of the " decapitated " the headwaters of rivers can even be tapped to dry valleys.

Strunk passes the Swabian Alb

After the gradual lowering of the Upper Rhine Graben and in consequence of the tectonic uplift and tilting of the Jura panel, the ratios of the two river systems ancient Danube Rhine and had each other changed fundamentally and permanently. With the formation of the Upper Rhine Graben and the Rhine in a lower base level of erosion was born. Through powerful headward erosion enlarged the Rhine and its Tributare their catchment areas to the detriment of the Danubian river system. The leading to Albtrauf right side tributaries of the Neckar - all Tributare of the Rhine - could therefore erode the northern edge of the Jura plateau steadily. Thus, the catchment area of ​​the Upper Danube was smaller around the north side of the Swabian Alb. In several cases Donautributare are already " tapped ". Even today, this is geologically long "battle for the watershed " further in favor of the Rhenish river system. Some of these rivers were formerly, and already in the Miocene and even up to the early Pleistocene powerful streams that drained large areas of southwestern Germany to the south. They originally drained into the Graupensandrinne and later in the developing ancient Danube. Inter alia are beheaded today: The rivers Schmiecha, Urlauchert, Urfehla ( Fehla ), Grosse Lauter and great- Lone (see the very small current Lone). " The valleys deleted from, with its wide valley bottoms in the air. "

Very young Strunk pass - education

A prime example of a relatively young Strunk passport was created by the tap of the so-called Feldberg Danube in the late Pleistocene (only about 20 000 years ago). A part of the former Feldberg Danube valley is now a broad, flat dry valley between Blumberg and the recent Danube E of Geisingen. In this valley there is a wetland and a meager trickle named Aitrach. The Feldberg Danube was beheaded by the Rhine, exceptionally fast eroding back border, Wutach: The Wutach has deepened her riverbed to now 165 m at a distance of 1 km!