PETROGRAPHY. 387 



vclopod in baiulssoiuetiiiies 100 yards across out of an ernptive ij^neous 

 mass during the i)rocess of its conversion into micaceous i;neiss. 



B. Lotti* claims to liave traced the white and veined saccharoidal 

 marbles of Carrara and the adjacent Apennines back into their un- 

 chan <?ed forms containing fossils characteristic of the Upper Trias and 

 jMnschelkalk. This metamorphism is ascribed wholly to the orographic 

 movements accompanying the uplifting of the mountain range. The 

 same agencies transformed the argilo-siliceous beds into mica-chloritic, 

 ottrelitic or other crystalline schists comparable with those of Archaean 

 age. 



MISCELLANY. 



The study of the interesting group of Peridotites assumed an almost 

 sensational aspect early in 1887 through the announcement by the late 

 H. Carvill Lewis t to the ettect that the diamond-bearing rock of the 

 Kimberly, South Africa, mines was a peridotite containing numerous 

 fragments of a highly carbonaceous shale, and that the diamonds were 

 doubtless secondary crystallization products due to the action of the 

 molten rock upon the amorphous carbun contained by them. In view 

 of the fact that Mr. J. 8. Diller| had but recently described a some- 

 what similar peridotite cutting carbonaceous shales in Elliott County, 

 Kentucky, the suggestion offered by Mr. Lewis's paper seemed of suffi- 

 cient promise to warrant the sending of Messrs. Diller and Kunz once 

 more to the latter locality in the hopes of linding contirmatoiy results. 



The fact that no diamonds were here found is ascribed to the paucity 

 of the shale in carbonaceous matter, IMr. Whitfield's analyses showing 

 but 0.081 per cent, of this material against 37.521 i)er cent, in the shale 

 of Kimberly. § 



Close upon the heels of this discovery comes the announcement of 

 the discovery by Professors Latschinof and Jerofeief of diamonds in a 

 meteoric stone found at Krasnosbbodsk, government of Penza, Kussia. 



If more i)roof were needed that serpentine never occurs as an original 

 deposit, but is always a product of the alteration of other minerals, this 

 has been abundantly furnished in two rather striking instances in this 

 country. A heavy dark dull green serpentinous rock occurring in the 

 Onondaga salt group at Syracuse, New York, and which had been in- 

 vestigated by Dr. llunt || and pronounced by him as an undoubted 

 iKiueous de])osit, as typically illustrative and confirmatory of his theory 



' IJnll. Soc. (;^()1. (l(i Fnince, 1888, Srd, 16tli, p. 4U(5. 



t GcoL Mag., .lannary, 1887, p. 22. 



t Bull. U. S. Geol. Survey, No. :58, 1887. 



^ Scienco, 1887, p. 140. It slionld bo iiotod Miat R. Cohen, as long ago as 1884 (Proc. 

 Man. Lit. and Pliiloa. Soc, October 7, 1884, p. ."j), projHJHod tlu^ igneous tiuiory for 

 tlic origin of diamonds, while. Maskelyno .still earlier announced that the diamonds 

 of both Kimberly and Borneo occurred in altered i)eridotic rocks. (Daubree, Ann. 

 des Minos, 1870, ix, p. i:?0.) 



II Am. .Jonr. Sci., xxvi, p. 261? ; al.so Min. Pliysiology and Physiography, i>. 447. 



H, Mis. 142 22 



