Professor Hoffmann on the Geology ofMassa Carrara. 119 



substance has also penetrated into the fragments, and fine scaly 

 green talc coatings are often to be observed. This brings to 

 our remembrance Savi's conjecture, that the peculiar marble 

 may owe its origin to a highly ferruginous vein of wacke having 

 penetrated into the limestone, — an occurrence which several ana- 

 logies point out. The red wacke veins of the mischio penetrate 

 like net-work the upper part, which runs in all cases parallel, 

 and consists of a pure white saccharine marble. This is changed 

 to Bardiglio in the superimposed mass, to which dark stripes 

 of mica running through it give a very beautiful watered ap- 

 pearance. Immediately above the quarries, which are carried 

 on to a considerable extent in the Bardiglio, the stripes of mica 

 are more crowded together, and form a stratum of distinct, well 

 characterized mica-slate. This, on the hanging side, becomes a 

 black clay-slate, upon which, in considerable quantity, and with 

 great regularity, a sandstone follows on the hanging side, which 

 is divided into beds of from one to three feet in thicknesS; and 

 often alternates with slaty marl ; and upon this sandstone lies an 

 extensive bed of limestone resembling rauchwacke. Near Staz- 

 zema, the sandstone becomes a fine granular quartz, and its 

 plates of mica become real slaty stripes. It alternates, at last, 

 in various ways with very considerable beds of pure clay-slate, 

 and above the whole series of strata, at a height of 1000 feet 

 above Strazzema, a distinct mica and talc-slate occurs, which 

 proves that we have not ye*^ left the region of the oldest forma- 

 tion of the chain. Similar conglomerated structures occur, in 

 various ways, subordinate to this slate formation ; but in no other 

 place are they so striking, and in such remarkable and peculiar 

 relations. This formation deserves particular attention, on ac- 

 count of its richness in metallic minerals in certain localities. A 

 mass of talc-slate to the south of Buosina is penetrated in all di- 

 rections by fine veins, and containing various sulphurets, vi^ 

 lead- glance, blende, antimony-glance, iron and copper pyrites. 

 This circumstance is a strong argument for the original injection 

 and sublimation of metals in mountsuns. Veins of iron-slance 

 are abundant, and even cross in great numbers the veins of the 

 sulphurets ; large veins of red ironstone, magnetic iron, and iron- 

 glance occur also in the slate, and a vein of this description has 

 branched round the fissures of a bed of true Bardiglio, and has 



