Sonntag, 28. Juni 2009

World heritage !

The Dolomites on Friday 26.06.2009 were accepted to enter the list of the UNESCO World’s heritage, not only for their natural, but also cultural importance.
The Dolomites played and play a central role for the history of geology and paleontology.

The stratigraphic succession of the Schlern mountain in a book of general geology of 1907.

The area of the Dolomites in the Southern Alps has attracted geologists since the early 19th Century, the vast outcrops and the sudden change of different lithologies – and so sedimentation conditions – was an ideal field for studying sedimentological and also tectonic questions. One of the most important achievements’ was the recognition that the outstanding carbonatic peaks and mountain groups are remains of ancient carbonate platforms and coral reefs. In early days of geology less was known about sedimentation in oceans, only selective probing was possible by dragging samples of the bottom of the sea, and so only in 1842 Darwin formulated a first hypothesis on atoll formation. Influenced by this model, intensive field mapping was carried out, and in 1860 the German geologist Ferdinand von Richthofen (1833-1905) recognised as first the organic origin of the carbonate rocks of the Schlern, in the valley of Fleims and Fassa. In the work of Johann August Edmund von Mojsisovics (1839-1907) “Die Dolomitriffe von Südtirol und Venetien” (1879), where he described the stratigraphic succession of the reef built-up and basin succession, the research on old reefs gave back important impulses to the interpretation of modern reefs.

In Leopold von Buch´s work "Esquisse d´une carte geologique de la parte meridionale du Tyrol" (1822) the author distinguishes carbonatic from dolomitic rocks.

In the map of Edmund Mojsisovics (1878) he distinguishes different formations by various different colors.

The outcrops in the Dolomites also helped to clarify an ongoing quarrel between geologist, proponents of the Plutonism, and geologist, proponents of Neptunism. The questions were if all know rocks have either a pure volcanic origin, or were deposited in an aquatic milieu.
The Italian mining engineer Conte Giuseppe Marzari-Pencati observed in 1806 in the valley of Fassa that granite covered carbonates, so the first has to be originated later. An impossibility for the scientific hypothesis of Neptunism of that time.

Sketch of the outcrop with granitic rocks protruding in calcareous rocks by Marzari-Pencati (1849).

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