Die Fossile Flora der Höttinger Breccie

Abstract

THE Höttinger Breccia is a formation about 50 feet thick in the neighbourhood of Innsbrück, and situated about 1200 metres above sea-level. The upper part consists of about 35 feet of coarse conglomerate, with fossils chiefly confined to a bed some 3 feet thick, while the remainder is occupied by alternating beds a foot or two in thickness of white or reddish sandstones and breccias, which are for the most part very fossiliferous. It has been well known to collectors of fossil plants for upwards of thirty years, and though at first regarded as of tertiary age, is now uniformly recognised as quarternary, possibly inter-glacial, or more probably post-glacial. The lower part is characterised by the occurrence of many herbaceous plants, such as the violet, strawberry, coltsfoot, Prunella, &c., which are replaced above to some extent by Cornus sanguinea, Rhamnus Frangula, an alder, willow, &c., indicating, perhaps, a change in the forest growth without necessarily implying any considerable interval of time. The flora is almost wholly of existing species, and in the main does not differ essentially from that which might be found in a similar situation at the present day; but six of the species no longer flourish at such an altitude, and a few others, like the box, are absent in Northern Tyrol, while there are also indications in the relative sizes of the leaves of others that the climate was milder. Perhaps the Alps were less elevated and the sea nearer at the time, but interest is given to the problem by the undoubted presence of Rhododendron ponticum, which at present only flourishes in a much warmer climate far to the east, but, from its discovery in other localities, was evidently thoroughly indigenous in the Alps. The author regards the flora as a relic of the “steppe-flora” which then spread over the greater part of Europe, and of which numerous traces still exist, especially in Switzerland and Lower Austria, where plants of Oriental facies, such as the yew, box, holly, Ephedra, Sumach, hornbeam, feather-grass, maidenhair, &c., are its lingering remains.

Die Fossile Flora der Höttinger Breccie.

By R. von Wettstein. With 7 plates. (Vienna: Imperial Printing Office, 1892.)