292 



of Aussee and Halstadt between the older Alpine limestone based 

 upon lias, and the newer limestone terminating in the Hippurite rock. 

 He afterwards gives various sections of the Vienna sandstone group, 

 and shows that it is the equivalent of the green-sand and chalk ; and 

 proves, by very elaborate details, chiefly derived from the banks of the 

 Traun, that in the enormous development of the nummulite series one 

 part graduates into the secondary, and another into the tertiary sy- 

 stem of the Eastern Alps ; thus confirming by new and uninterrupted 

 sections the justness of our former classification. 



Among the novel and important observations in this Memoir, the 

 author describes a deposit, at Ortenburg in the valley of the Danube, 

 composed of chalk with flints, supporting tertiary sands and clays, and 

 resting horizontally upon the primary rocks of the Bohemian chain. 

 Arguing from this fact he shows, (agreeably to the system of M. Elie 

 de Beaumont,) that the elevation of the Alpine and Bohemian chains 

 took place at two distinct periods. 



In glancing over the various papers on the structure of the Eastern 

 Alps, it was impossible for me entirely to separate the descriptions 

 of the older and newer systems ; but I now proceed to notice some 

 communications almost exclusively devoted to the phenomena of ter- 

 tiary deposits. 



A paper was laid before the Society by Mr. Murchison and myself, 

 during the past year, on the Tertiary Formations of Lower Styria. 

 In an east and west section, from the Styrian Alps to the confines of 

 Hungary, we describe along succession of marine strata; commencing, 

 as we have endeavoured to prove by the imbedded fossils, with rocks 

 of the Palseotherian period, and ascending through the middle Sub- 

 Apennine system to a large group of strata, apparently containing 

 several species of recent shells, and of the same age with the higher 

 deposits of the Vienna basin. Yet in this most recent group are masses 

 of limestone exhibiting so fine an oolitic structure, that by hand spe- 

 cimens alone we should find it no easy task to separate them from the 

 great oolite of Bath. 



In another section from north to south, we have shown the asso- 

 ciation of the upper tertiary groups with the rugged volcanic rocks 

 which start out from the eastern plains of Styria : and from all the 

 complicated phenomena we conclude, that the volcanic forces were 

 first called into action in this region during the most recent tertiary 

 period, and were probably continued for a long succession of ages, 

 during which the sea was spread over the lower portions of Styria 

 and Hungary ; and that no test can be established whereby we can 

 fix the ages of the different igneous productions : inasmuch as the 

 same groups of strata are in one place covered by basaltic lava, in 

 another by trachyte, in a third by volcanic conglomerate, and in a 

 fourth alternate with volcanic sand and breccia. Lastly, we have in 

 the discontinuous masses of volcanic breccia, and in the rude and 

 interrupted escarpments of trachytic and basaltic rocks, the clearest 

 and most emphatic proofs of enormous degradation, within a period 

 of time bounded by one of the newest regular formations of geology. 



"Before quitting this subject I may add, that Mr. Murchison has, in 



