Blocks of orbicular Granite discovered in Corsica* ^$ 



Itnt colour, was softer^ and did not receive the brilliant polish 

 of the orbicular granite. M, Rampasse brought to Paris 

 some magnificent specimens of this porphyry with large 

 globules. This variety was not to be found in any cabi* 

 nets. 



It results from these details, that all hopes were given up 

 of other masses of granite similar to that of the plain of 

 Talavo, when a particular circumstance brought to view 

 several other blocks, which are said to exist in their naiiva 

 position, a leage from Talavo, and resting on the same 

 rock which gave birth to them. 



It is to M. Mathieu, captain in the imperial artillery^ 

 and commanding at Ajaccio, that we owe tlie first infor- 

 mation on this discovery, consigned in a manuscript me-» 

 inoir, accompanied with a topographical plan, and a verjs 

 excellent specimen of this granite, which is of precisely 

 the same form with that which was formerly discovered. 



" This superb production,'* says M. Malhieu, " is found 

 in considerable masses on the estate of Sartene, the pro- 

 perty of M. Jean Paul Roccaserra : its present situation is 

 about three fourth parts up a very steep mountain, from 

 which it has been msulated by accident; it is in blocks 

 smoothed (arrondis) i?i consequence of decomposition, which 

 blocks are comprised within a space which does not extend 

 beyond four himdred square metres. The base is a granite 

 composed of semitransparent quartz, of amphibole with 

 large crystals, and of mica in a small quantity : sometimes 

 shades are discovered which give a feeble appearance of the 

 globulous system. The rest of the mountain is, like thosa. 

 adjacent, composed of a granite of quartz, feldspar, and 

 mica." 



M. Mathieu adds, that the lichens and mosses which 

 covered the blocks of this new orbicular granite and con- 

 cealed its characters, did not permit those who visited the 

 same mountain to see that the discovery was owing to tho 

 recent separation of tivo parts of one block* The distance 

 of the position of the ancient block of Talavo from the 

 Rizenare, a river which washes the foot of the mountain oa 

 which the recent discovery has been made, is one myria- 

 metre and a half. M. Mathieu does not think that this 

 liver has ever been capable of transporting this old block 

 of granite to such a distance; and he is perfectly right : but 

 when he presumes that, " in very remote ages, this same 

 block has been discovered in the Rizenare, and thence trans- 

 ferred by the care of an architect to the spot where it was to 

 he cut with the cA/^e/,"— this conjecture does not seem to 



rest 



