Wetterstein limestone

Wettersteinkalk weather stone dolomite are the most common name for a carbonate rocks of the Middle Triassic, the Ladin time step, comparable to the German stage of the Muschelkalk.

Sub forms include Messerstichkalk, Schlern dolomite, Marmolatakalk, Steinalmkalk and Ramsau.

The rock is prevalent throughout the Alps, in some places as limestone (calcium carbonate), in some places. Than dolomite with an additional amount of magnesite Since the dolomitization by recrystallization Fossil traces tend to be canceled, the fossils are in the weather stone dolomite even worse, barely visible even in thin section. Weather dolomite stone is rarely as bituminous and therefore usually much purer and lighter colored than the typical main dolomite. Otherwise, no fundamental differences from the same lime are known.

The name derives was the Wettersteingebirge because the Wettersteinkalk is particularly mighty mountains here. But its distribution area he owns in the Karwendel mountains. In some areas there occurs a engräumiger change from lime and Dolomitfazies.

Construction

At least for the areas in which the Wettersteinkalk is powerful, should generally apply the following layer sequence:

• The lower Wettersteinkalk is gebankt and dark -colored; it often contains echoes of the clayey Partnach layers or siliceous limestones Linger frost or alpine limestone.
• The mean Wettersteinkalk is a bright, unstratified reef limestone, it forms the summit area about the Laliderer tip.
• The upper Wettersteinkalk is also hellfärbig, but again gebankt very clear with similarity to the Lofer - Zyklothemen the Upper Triassic. His distinct benches for example, form the summit of the Birkkarspitze and Kaltwasserkarspitze.
• In the higher parts of the Wettersteinkalkes there are occasional layers in which about the size of lentils shallow cavities are present in the limestone, the cavities are oriented in all directions. This variant is also referred to as Messerstichkalk. It has been suggested that originally had been instead of the cavities gypsum crystals, the gypsum can be later resolved by leachate or converted into lime according to the following reaction with the participation of natural gas:

Mark

Characteristic of the Wettersteinkalk is its high purity and its resistance to erosion, which is why it forms extremely steep and daunting cliffs such as the Hochwanner North Face in Wettersteingebirge (1400 m thick ).

Mountaineering Risch he is therefore a special attraction for both climbers and hikers, as many classic climbing routes are in Wettersteinkalk. Extremely attractive mountains such as Zugspitze, Alpine peaks, Birkkarspitze, Lamsenspitze, Scheffauer and Säuling consist of Wettersteinkalk. Also typical is the widespread karstification, which manifests itself in the occurrence of sinkholes, caves and karst formations.

A further consequence of its high resistance to abrasion is the preservation of old surfaces from the Tertiary, ie high-lying relatively flat surfaces that have been by river erosion is not cut ( zertalt ), thus an ancient landform from the Tertiary to the present day well retained. Good examples are the Zugspitze, the Leutascher Platt and the Höllentalkar. In most areas, the tertiary widespread levels have been converted by fragmentation through waters in ridges and valleys.

Occurrence

In all the Northern and Southern Limestone Alps forming either summit or in the underground of the mountains. Summit development it he is in:

• Karwendel and weather stone ( with the Zugspitze ), including Mieminger chain, except only a few mountains around Seefeld in Tirol
• Further west the Heiterwand
• Wild and Tame Emperor, and a mountain range to the west with Guffert
• Edge of the Alps, the great rocky peaks of the Tannheimer Mountains and parts of the Oberammergau Alps (eg Säuling, high disk), the Staufen near Reichenhall, Höllengebirge and Traunstein in the Salzkammergut and the Sengsengebirge.
• Rax and Schneeberg

In the Southern Alps, especially:

• Whose highest mountain Marmolada
• And the mountains on the western edge of the Dolomites ( where the upper dolomite is already removed ): Geisler, Schlern and Sasso Lungo, Rosengarten, Latemar
• In the south of the Dolomites Palagruppe

Local names

• In the Southern Alps, the rock series is mostly dolomitized available and is mostly occupied with the name Schlern dolomite.
• But precisely at the Queen of the Dolomites, the Marmolada, the highest mountain, the rock longer present chalky and says there Marmolatakalk. This name, however, remains purely local, as in the neighboring mountains consistently present dolomite.
• In parts of the Northern Limestone Alps lies in some areas before a very close interrelationship storage and a flaking of lime with the Dolomitfazies. The Carnic level has remained without any sediment, so that the limestones and dolomites of the Ladiniums with those of Noriums practically related. Between the weather stone dolomite ( Ladinian, Middle Triassic ) and the main dolomite of the ( Norian, Upper Triassic) to see there is no difference, so both stages there be summarized as Ramsau, which is identical with the weather stone dolomite in the latter only the lower part. This summary is for the convenience of the mapping geologist.
• In parts of the Northern Limestone Alps are found at the beginning of the ( anisische stage) Middle Triassic the Wettersteinkalk a very similar rock with Diploporen as fossils. If this limestone above still follows another rock from the weather stone dolomite, this is therefore separable from the weather dolomite stone, it is considered Steinalmkalk, after Steinalm in Saalfelden designated.

In the 19th century it was known as Lower alpine limestone, in reference to the fact that another very powerful stack of carbonate rocks (limestone or dolomite ) from the Upper Triassic layered above or once encamped.

Fossils

Dasycladaceen ( Wirtelalgen ) with the typical kind Diplopora annulata with a growth habit similar to a horsetail and a limestone skeleton around the stem. The fossils are macaroni -like calcareous tubes of different sizes, both inside and outside notched so that the parts of the stalk from the outside as money rolls look so curled ( annulata ). A closer microscopic examination shows that the tubes are perforated by fine channels. These channels bifurcate from the inside out into two branches, hence the name " Diplopora ".

The Diploporen built on all the reefs, so they are still occasionally get in an upright position in the stone. They were, together with calcareous sponges, the only Riffbildner because the root of the coral had suffered so much from the mass extinction at the Permian-Triassic era that reef -forming corals were not yet available at that time again.

Ore deposits

Typical of the Wettersteinkalk is a mineralization of lead and zinc ( galena and sphalerite ), which is spread over almost the entire northern and over large areas of the Southern Limestone Alps. Most famous are the ore deposits of Bad Bleiberg west of Villach in Carinthia, Raibl in Friuli and Mesica in eastern Slovenia. In the northern Alps was in the 50s an occurrence in the Karwendel mountains ( Lafatsch in the Kastenalm in Hinterautal ) studied, but not degraded due to low mineralization and low inventories. In the past, many other deposits were workable, such as Rauschenberg in Ruhpolding, the Staufen near Reichenhall, etc. The Karwendel, Wettersteingebirge and the Mieminger mountains, as well as on the Heiterwand were mine workings (St. Veit, Nassereith, Dirstentritt ). Economically important was the late middle ages / early modern times in addition to the lead, which was the extraction of silver from the copper ores of Schwaz, even the relatively low silver content of the galena ( 100-200 g / ton of lead; see about 0.5 % silver in Schwaz tetrahedrite ). On Säuling mineralization of Wetterstein / dolomite with ankerite ( weathered limonite ) was used as iron ore. In the years around the First World War molybdenum deposits ( Wulfenite ) were important in the same ores, here are especially the workings at Bleiberg and Mies ( Mesica ) should be mentioned, the experimental reduction in Höllentalbahn the weather stone despite great efforts resulted in no appreciable quantities of ore. The mineralization must have been practically synsedimentary essentially, that is still during the Wettersteinkalk or later than the Raibler layers were deposited, since the higher limestones or dolomites of the Norian stage of the veins in no case be achieved.