118 Professor Hoffmann on the Geology of Massa Carrara, 



not find it in such unusual connexion. Petrifactions were not 

 met with ; an ooUtic structure is sometimes, though rarely, ob- 

 servable. Usually the limestone is broken up into sharp-cor- 

 nered fragments by innumerable fissures, and when its sandy 

 looking granular structure is clearly exhibited, it looks like an 

 impure dolomite. Stripes occur resembling those of the Ranch- 

 wacke limestone. Farther in the interior of the mountain the 

 more or less considerable limestone and dolomite layer ceases, 

 and at last the beautiful brilliantly white marble commences. 

 The blocks of marble, still having a prismatic form, are always 

 surrounded by more or less considerable stripes of green talc- 

 idate abounding in iron-pyrites, which rock so completely en- 

 eases the niarble on all sides, and is so completely amalgamated 

 with it, that it almost appears as if the pure granular limestone 

 had been separated from the talc-slate in a liquid condition. 

 Where the latter penetrates the limestone, and does not separate 

 itself in distinct layers, impure coloured and striped Bardiglio 

 is generally produced. In the midst of the mass of pure, fully 

 formed marble, we not unfrequently see completely enveloped 

 traces of dark grey nearly compact limestone, having irregular 

 fissures, and so completely amalgamated with the including mass, 

 that we might easily regard them as fragments of the impure 

 limestone layer, upon which the altering action that produced 

 the marble could not complete the chaijge. To the east of both 

 the chief branches of the valley of Senavezza, in the valley of 

 Versiliu, the talc-slate dips at first at a high angle to the south- 

 west ; but where the deep lateral valley of Ruosina commences, 

 this position is changed. No gneiss appears under the slate, 

 and the last dips, in a direction up the valley, to the north-east. 

 At the Polite Stazzemese an impure grey limestone reposes on 

 the slate, and in all its relations reminds one exceedingly of the 

 external layer of Monte Altissimo. Upon it follows, towards the 

 C di Molina regularly superimposed, the peculiar marble, 

 known under the name Mischio d'l Senevezza, This mischio 

 exhibits a great number of sugar-like, granular, white lime- 

 stone fragments, included in a dark, iron red, compact clay- 

 stone basis, in ^vhich not unfrequently fine needles of hornblende 

 occur. At the planes of contact, the red coloiir of the uniting 



