1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 221 



with the submarine deposits, — a class of strata now too well known 

 to require further illustration f. At the same time I know that this 

 region also abounds in igneous rocks of a truly erui)tive character 

 which have penetrated and cut through the whole of the stratified 

 masses. Examples of both these classes of former volcanic or plu- 

 tonic action are sometimes to be seen in the same hill, as exhibited in 

 the above woodcut. The chief masses or ledges of nummulitic lime- 

 stone which thus surmount the scaglia, dip on the whole southwards 

 to pass under the marls, tuffs, sands and limestone of the undulating 

 hills of the Vicentine, and thus the nummulitic limestone is fairly 

 seen to constitute the base of that shelly group, even in a tract much 

 traversed by basaltic matter. But in proceeding to the west and 

 south-west of Schio, the igneous rocks so abound, that a regular 

 sequence, I repeat, is not traceable for any considerable distance. To 

 the north of St. Orso near Schio, indeed, the effects of the intrusion 

 of a great mass of porphyry have been such as completely to invert 

 the strata and to fold back the cretaceous rocks and make them over- 

 lie first the nummulitic and then the other and younger tertiary 

 rocks ;|:, as expressed in the diagram (fig. 26). This point will be 



Fig. 26. 

 N.N.w. Inverted Strata. S.S.E. 



p a b c d* d e f f g 



p. Porphyry. fd. WTiite scaglia. g. Sandy limestone C.voungest beds). 



d*. Red scaglia. /. ? Blue marls. 



Cretaceous. 



j c. Grey scaglia. /. Sand and clay. > Eocene. 



La & A. Neocomian. e. Shelly tuff and bone-beds . J 



reverted to when the dislocations and inversions in the Alps are con- 

 sidered, and I now proceed very briefly to direct attention to the clear 

 and unambiguous sections of Bassano and Asolo (figs. 22 & 23), which 

 have, in fact, proved to be, what I ventured to suggest so many years 

 ago, the best expositions of the true normal succession from the cre- 

 taceous to the tertiary rocks which have anjnvhere been observed on 

 the flanks of the Alps. (See back, pp. 218, 219.) 



On the right bank of the Brenta at Campese, a little above Bassano, 

 the neocomian and scaglia, which range in great undulating terraces 



t M. Brongniart has described in some detail these rocks, which he has called 

 " calcareo-trappeens." I only differ from my lamented friend in considering some 

 of his " brecciole " as being contemporaneous with the deposits. 



^ In common with all the members of the Geological Section from Venice, I 

 was exceedingly obliged to my able friend, M. Pasini, for the pains he took to 

 make me better acquainted with the interesting tract around Schio, Recoaro, and 

 the Setti Communi, with which he has been so long conversant. The tract which 

 has given birth to Arduini, Brocchi, Fortis, Mazzari Pencati, Maraschini, and 

 Pasini, may well be considered classical in geology. In this region every variety 

 of dislocation is to be seen w'ith much metamorphism of mineral structure ; and 

 yet it is here that the best development of the trias is displayed, as well as 

 a copious series of Jurassic, cretaceous and tertiary deposits. 



VOL. V. PART I. R 



