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Show 212 MIOCENE PlmtoD. [Ch. XV. sition of the Miocene and older Pliocene beds. It is, however, ascertained, that the highly-inclined green sa~, ";'hic~1 comes immediately in contact with the primary roc s, Is t e oldest part of the ser1.e s *. Molasse of Switzerland.-If we cross the Alps, and pass from Piedmont to Savoy, we find there, at the northern base of the great chain and throughout the lower country of Switzerland, a soft O'reen sandstone, much resembling some of the beds of the basi~ of the Bormida, above described, and associated in a similar manner with marls and conglomerate. This formation is called, in Switzerland,' molasse,' said to be derived from 'mol,' 'soft,' because the stone is easily cut in the quarry. It is of vast thickness, but shells have so rarely been found in it that they do not supply sufficient data for correctly determining its age. M. Studer, in his treatise on the ' molasse,' enumerates some fossil shells found near Lucerne, agreeing, apparently, with the testacea of the Subapennine hills. The correspondence in mineral character between the green sand of Piedmont and that of Switzerland can in nowise authorise us to infer identity of age, but merely to conclude that both have been derived from the degradation of similar ancient rocks. Until the place of the ' molasse' in the chronological series of tertiary formations has been more rigorously determined, the application of this provincial name to the tertiary groups of other countries must prove a source of ambiguity, and we regret that the term has been so vaguely employed by M. Bom~. Sty ria, Vienna, Hunga·ry, ~c.-Of the various groups which have hitherto been referred to the Miocene era, none are so important in thickness and geographical extent as those which are found at the eastern extremity of the Alps, in what have been termed the basins of Vienna and Styria, and which spread thence into the plains of Hungary. The collection of shells formed by M. Constant Prevost, in the neighbourhood of * We trust that MM. Pareto, Passini, Sismonda, and La Marmora, will devo~e their attention to the relative vosition of the several groups of terti~ry str~ta Ill Piedmont 1 b)' instituting a comparison between their respective orgaruc remams. Ch. XV.] STYR TA-VIENNA-HUNGARY. 213 Vienna, and described by him in 1820 *, were alone sufficient to identify a great part of the formations of that country with the Miocene beds of the Loire, Gironde, and Piedmont. The fossil remains subsequently procured by that indefatigable observer M. Boue have served to show the still greater range of the same beds through Hungary and Transylvania. It appears from the recently published memoirs of Professor Sedgwick and Mr. '.Murchison f, that the formations in Styria may be divided into groups corresponding to those adopted by M. Partsch for the Vienna beds; the basin of Vienna exhibiting nearly the same phenomena as that of Styria. These regions have evidently formed, during the Miocene period, two deep bays of the same sea, separated from each other by a great promontory connected with the central ridge of the eastern Alps. 'fhe English geologists, above mentioned, describe a long succession of marine strata intervening between the Alps and the plains of Hungary, which are divisible into three natural groups, each of vast thickness, and affording a great variety of rocks. All these groups are of marine origin, and lie in nearly horizontal strata, but have a slight prevailing easterly dip, so that, in traversing them from west to east, we commence with the oldest and end with the youngest beds. At their western extremity they fill an irregular trough-shaped depression, through which the waters of the Mur, the Raab, and the Drave, make their way to the lower Danube i· They here consist of conglomerate, sandstone, and marls, some of the marls containing marine shells. :Beds also of lignite occur, showing that wood was drifted down in large quantities into the sea. In parts of the series there are masses of rounded siliceous pebbles resembling the shingle banks which are forming on some of our coasts. The second principal group is characterized by coralline "' Journal de Physique, Novembre, 1820. t Geol. Trans., Second Series, vol. iii. p. 301. t Ibid., p. 382. |