TRANSLATIONS AND NOTICES 



GEOLOGICAL MEMOIRS. 



On Me Discovery o/" Jurassic Plants m Me Venetian Alps. 

 By Cav. Achille de Zigno, 



[Leonhard u. Bronn's Jahrb. f. Min. u. s. w. 1854, pp. 31-35 ; 

 with a lithographic plate of sections.] 



In the Venetian Alps, above the series of dark grey Hmestone and 

 reddish sandstone, which are referred to the Trias, and under the 

 white hmestone with Neocomian fossils, reposes a thick series of cal- 

 careous strata, sometimes crystalline, sometimes compact, and fre- 

 quently oolitic in structure, and occupying precisely the place of the 

 Jurassic rocks of the other countries of Europe. 

 Order of the Strata in the Val , A* «?«^! P^^'^^s the lower part of 

 d'Assa (Rotzo), in the Fi- this series is composed of slaty clay. 



centin, and in the Val Tanara 

 (Pernigotti), in the Veronese. 



Neocomian. 



Callovian and Oxfordian. 



Bathonian. 



(with the plant-bed). 



Bajocian. 



Dolomite (Lias). 



Trias (not seen). 



brown or greenish in colour, of 

 sandstone-conglomerates with py- 

 roxenic elements, and of greyish 

 violet limestones with crystalline 

 veins. In the Cadore district, 

 along the valley of the Boite, and 

 in the Agordo district, we easily 

 find the rocks which occupy the 

 place of the Lias, although the 

 absence of fossils prevents us at 

 present from referring them with 

 certainty to a determinate position. 

 In the great valleys of the Piave, 

 Brenta, Astico, Agno, and the 

 Adige,we do not observe the above 



conditions ; but, on the contrary, crystalline limestones in consider- 

 able force here form the base of the .Jura and Lias. 



In the rocks in question fossils are very rare, and the few traces 

 which I met with consisted of some casts, referable perhaps to Trochus 

 and Chemnitzia, and having indeed much resemblance to the liassic 

 species of other countries. The crystalline limestone in the upper part 

 contains some subordinate beds of compact limestone ; and this group, 



VOL. X. — PART II. ■ D 



