



PHYS1 



s 



Cía 



SS 1 





Order 3 



Sal 



> 



1 



1 



Y 5 3 



Q :; 5 



Pers 



alai 



IC 



( !ol uinbare 



Rang , 







Subraug 3 



K,0'+Na t O' : 



GaO . ' 



Peralkalic) 



k.,0 .V 3 . 

 Ñ¡75 3 : 5( Sod, P° tassic ) 



Uaskase 







Vlasl>ose 







isvw's CLASSIFICAT10K 



S =82 .oí) 





n= h 



.96 



A= 6.65 



C = ■>. . 1 7 





a=i4 



• 7 / 



F = . :>. - 





/= 



■ :,( .) 



The rock has a palé reddish-grey colour. It is holocrystallíne, 

 phanerocrystalline and millimeter-grained. 



The essential minerals are discernible with the naked eye. They 

 are : microcline, albita, quartz, muscovite and biotite. 



The accessory minerals are apatite and magnetite. 



More over kaolinite and muscovite occur as secondary constituents. 



\li the minerals show signs of mechanical deformation. It appears 

 however that the deformation is in its first stage. The feldspars are 

 somevvhat bent, the quartz shows a developed undulóse extinction and 

 finally the micas are distorted but I have not observed a sure peri- 

 pherical granulation. There are however accumulations of quartz 

 grains of variable magnitude from sections of i mm. in diameler and 

 more, to those with a diameter below 0,1 mm. which malees one sus- 

 pect that a kincl of granulation has taken place. The quartz grains are 

 quite irregular and not only do they show undulóse extinction but they 

 appear sometimes divided in small fragments in the periphery, the 

 fragments holcling together with the crystal. 



Microcline. — After the quartz, this mineral is the most common in 

 the rock. In thin sections the colour is white. The área of the measured 

 sections of microcline varies generally between 12 mm 2 and 1 mm 2 . 

 The largest sections seem to be those parallel lo (001), then follow 

 those according to (010). The crystals appear to be somewhat elongated 

 in the direction of the edge (001), (010). 



Polysynthetic twinning according to the albite and pericline laws 

 always present. The lamellae are very fine. 



Cleavage (001) good, (no) not so good, (010) distinct but not good. 



The shapes of the crystals are generally anhedral and somewhat 

 prismoid. 



