1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 289 



At Canniparola, on the west side of the valley of the Magra near 

 Sarzana, coal supposed to be of mioeene age has been worked in several 

 seams, and is associated with many plants of dicotyledonous structure. 

 These works are now abandoned. On exploring the natural out- 

 crop of the mineral, on the sides of the torrent called La Girona, I 

 perceived that the coal seams subordinate to shale with plants, re- 

 posed, in highly inclined strata dipping to the west, on shale with 

 calcareous nodules. The latter passes downwards into a soft macigno 

 or finely micaceous sandstone, and from that into dark-coloured and 

 party-coloured schists and marlstone with conchoidal fracture. Below 

 these there appeared to me to be a transition into true hard and older 

 macigno with white veins, the inclination increasing to verticality with 

 the slope of the mountain sides. These beds being partially dislo- 

 cated, strike both a little to the west and a little to the east of north ; 

 but the main direction is north and by west, and south and by east, 

 or parallel to the chief ridge of the Apuan Alps, from which they 

 are separated by a vast mass of underlying macigno. On the other 

 hand, the coal strata are surmounted by ochreous sandy conglome- 

 rates, which being further removed from the axis of elevation, dip 

 down to the vale of the Massa at a less inclination, and are lost in 

 alluvial accumulations. 



A traverse of the Apennines from Bologna to Florence exhibits, on 

 the flanks of the chain near the former city, blue marl and sand of sub- 

 apennine age, reposing on micaceous sandstone. 



These masses, thus exposed in a low anticlinal on this outer parallel, 

 are better seen on the high road as you pass by Pianura to Lojano, 

 arranged in an elevated trough, near the north-western side of which 

 courses of lignite (1) are surmounted by nodular strata and shelly 

 blue marls, and these by the sands and white marls on which Pianura 

 stands. Above these come other sandy marls with large nodules 

 of dark grey, micaceous, ferruginous marlstone, in which I found 

 many Cardia, Pectunculi, Nuculse and Venericardise. These shelly 

 beds, overlaid by a vast thickness of blue marl (2), and covered by 

 yellow and white conglomerates and sands (3), are clearly the sub- 

 apennine group of Brocchi, which, after dipping for a certain distance 

 to the west, are bent up in a trough. From the summits of the con- 

 glomerate hills near Lojano, the dip being reversed, or to the N.E., 

 the subapennine group is supported on the other side of the basin by 

 nodular strata, together with a system of soft micaceous sandstones and 

 pebbly conglomerates of considerable thickness, which alternate with 

 certain shaly marls and greenish sandstones. These lower, undulating 

 sandstones and conglomerates with marls, &c. most clearly represent 

 the Superga series (A of fig. 36), and are of mioeene age. In the con- 

 struction, therefore, of a detailed geological map, this portion of the 

 east flank of the Apennines might be shown to exhibit two axes or 

 undulations of miocenic sandstones and conglomerates, troughing be- 

 tween them a mass of true subapennine beds, and again throwing off 

 the upper beds towards the low country. iVt Lojano, the second post 

 from Bologna (as it appeared to me in a rapid survey), the mioeene 

 conglomerates are cut off by a longitudinal fault from the macigno, 



