38 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



calcite or quartz are seen to have been drawn out into lenticular 

 ' eyes ' in a rock mass that has been subjected to great pressure and 

 torsion. The presence of the narrow bands of gneiss in the limestone, 

 described by Mr. Barrington Brown, 1 seems also to me to militate 

 strongly against the acceptance of Professor Judd's theory, for it is 

 not easy to see how these bands could have escaped the alteration 

 which, according to that theory, has entirely destroyed the gneiss 

 on both sides of them. It is true that Professor Judd does not assert 

 that the calcite has been entirely crystallised in situ, for he adds to 

 his explanation of the process by which the original felspars of the 

 basic gneisses have been transformed into scapolite, by ' Werner - 

 itisation,' and from that to calcite by ordinary decomposition, the 

 words 2 : — 



" If this be the case, it is, of course, necessary to suppose that the 

 calcium carbonate has been often transported to new localities in solution, while 

 the basic aluminium and other silicates have in some cases been broken up, 

 so as to give rise to tlie formation of corundum, spinel, and the various 

 other minerals occurring in the limestone or in the rocks so closely associated 

 with it." 



If such a transference of the carbonate of lime has taken place, 

 and if this re-distribution of that mineral is supposed to account 

 for the thick bands of practically pure calcite now to be seen, 

 the theory would seem to require that the anhydrous alumina should 

 have been transported in the same way by solution and re-deposition. 

 Otherwise the gems would not now be found in the body of the 

 limestone. Surely these minerals would have been left behind, 

 and should now be found in the gneiss bordering on the lime- 

 stone, where, it is quite certain, they do not occur at all. 



The cipolins of Ceylon, which are also associated with pyroxenic 

 Crystalline limestones gneisses, have been described by M. Al. 

 of Ceylon. Lacroix,3 but no complete account is given of 



the genesis of the limestones. M. Lacroix remarks (Records, p. 195) 

 that at Cornigal (Kornegalle) elliptical masses occur in the cipolins 

 made up of a mixture of different minerals and presenting a composition 

 closely comparable to that of the pyroxenic gneisses of the same region, 

 and infers that they have been derived from the cipolins. In this case 



1 Loc. cit., p. 175. 



2 Loc. cit., p. 215. 



3 Gneissose rocks of Salem and Ceylon ; Bull, dc la Soc. Franc, dc M inerdlogie, XII 

 (1880) ; translated by Mr. F. R. Mallet in Records, Ottol. Surv. Ind., Vol. XXIV, Pt. 3 

 (1891). 



