. i'KM II i;sKf)i.A. M.-N. K! 



the f^rccnschist lacics. AIiIimiil;!) this is no rare case and the re-cry.stal- 

 li/.ation of such li\(lr;it((l iiiim rals may he f|iiantitatively considerable, they 

 a|)i)eai', hovvtvci', (lisliiiclK- apart t'idiii llic aiiiphibolitization. 



'l"he most c o n s p i c n o ii s altération of the eclogites in 

 Nord fj Old and More is that into the am p h i bf> 1 i t e fades. At 

 its first stai;(_' its pyroxene is r e c ry s t a 11 i z e d, in a curious 

 way, every grain eating itself into some of its neighbours 

 and at the same time separating fxit pi agi o ci ase in symplec- 

 titic intergrowth with the pyroxene. Chemically this change 

 prohahls' means a breaking ii [:> of the aluminous pyroxenes, 

 containing jade i te and 1 i m e-j a d e i t e, into diopside and soda- 

 1 i m e fe 1 d s p a r. 



A n o t h e 1- a 1 1 e rati o n is t li e g r o w t h o f g r e e n ho i" n b 1 e n d e 

 as shells around the garnet and at its expense, the kelyphite. 

 This zone may grow thicker and spread c) u t into the py- 

 r o X e n e m a s s. 



At a final stage all the diopside of the d i o p s i d e-pl agi o- 

 cl ase-s \- m 1)1 eet i tt- is ui-alitized with preserved structure 

 which, however, will gradually altti-, the hornblende tend- 

 ing to d e \' e 1 o p a j) r r s m a t i c habit and the p 1 a g i o c 1 a s e to be 

 granulated. The end product is a granular am phi bol i te, with 

 o r w i t h o u t garnet, in w h i c h g r o u {) s o 1' parallel short pris m s 

 of hoi-nblende are the only reminiscence from its earlier 

 pyroxene and aggregations of green hornblende, often with 

 magnetite, from its garnet. 



There is practically no doubt that this is the same process as that 

 formerly described by Lacroix, Laura Hezner, S. Franchi (feldspar-uralitiza- 

 tion) and others, but the earlier investigators have not followed it through 

 its different stages, viz. the formation of diopside-plagioclase-symplectite, 

 the kelyphitization and the uralitization, nor have they recognized the 

 mutual relations or the petrological importance of these processes. 



Change of Facies during Crystallization. 



Ainpliibolc-ccloi^ilr. 



Among the eclogite minerals we have repeatedly mentioned the 

 occurrence of pale green hornblende that is primary, although it has 

 originated at the expense of the two chief eclogite constituents and appar- 

 ently did not belong to the equilibrium together with them. By exhau- 

 stion of the pyroxene, amphibole-eclogites may result. 



Such rocks have changed facies during their crystallization. 1 have 

 not observed gradual transitions from such amphibole-eclogites into true 

 amphibolites, and it seems as though the former would belong to an inde- 



