220 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 13, 



and Vicenza on the south, this scaglia is copiously developed, and 

 maybe seen in numerous sections underlying the nummulitic limestones. 

 Near Val d'Agno, to the south of Recoaro, the scaglia with its cha- 

 racteristic fossils is directly overlaid (as expressed in this woodcut) by 



Fig. 24. 

 Relations of Lignite to Scaglia and Nummulite Limestone. 



S. N.B. In this figure the north has been accidentally reversed. N. 



/. Nummulite limestone. 

 e. Lignite coal shale. 



d. Scaglia or chalk. 



seams of coal worked for use in that neighbourhood, which lie in shales 

 that dip away from the older rock, and pass under the adjacent hills of 

 nummulitic limestone. In fact, these coal-beds occupy the same 

 place as those of Entrevernes in Savoy, of the Diableretz, and of the 

 Beattenberg in the canton of Berne (see p. 189). There are, indeed, 

 other localities in this region where the nummulitic rocks are equally 

 characterized by containing lignites or coal, as at Monte Bolca, and 

 at Monte Viale near Vicenza, where it occurs in the escarpment of 

 the well-known coralline limestone of that insulated mount. 



In the tract between Vicenza, Schio and Verona, the various se- 

 dimentary deposits are so penetrated by diflPerent eruptive rocks, 

 whether porphyries, trachytes, greenstones, basalts or serpentines, 

 and peperino, that the dislocations and interruptions are frequent, 

 and the original order of succession with difficulty observed, particu- 

 larly around Ronca, Montecchio Maggiore, and other localities noted 

 for their organic remains. To the west of Schio, however, and above 



c Dykes. 



/. Nummulite limestone. 

 e. Shelly volcanic grit. 



d* 



e f Eruptive rocks. 



rf*. Red scaglia and white. 

 c. Grey scaglia. 



the town of Magra, another instructive section is exposed (fig. 25), 

 the base being composed of the red and white scaglia, in which Ino- 

 cerami, Terebratula incurva, Ananchytes tuberculafus and other 

 fossils occur, whilst the summit is occupied by strong bands of num- 

 mulitic limestone. The beds being only slightly inclined, a perfect 

 conformity is observable, as well as a transition from one group to the 

 other. There are here no coal-seams, but towards its upper limits the 

 red fissile scaglia (c?*) alternates several times with basaltic trap tuff, 

 some of the highest beds of which above the scaglia are just as much 

 loaded with nummulites as the hard grey nummulite limestone (y) 

 which crowns the hill. The manner in which certain bands of these 

 tuffs are thus interlaminated with the nummulitic strata here, and 

 with other shelly strata of this age in the adjacent tracts, induces me 

 to think that they were volcanic dejections formed contemporaneously 



