I'age 

 Kciuiiniits (if prelniite u'rouiis in st ilMte I."." 



l'relniit(,» cut by vein of npoijliyllite l.'r, 



Masses of peetolite needles and isolated reiiniauts of same in tlie midst of 



apopliyllite los 



INnous. decomposed nnalcite. penetrated by needles of natrolite I6r> 



Keplaceuient of cliabazite by lienlandite 108 



Iteplaeement of cliabazite by stilbite and of both by natvolite ]<;;"• 



Phantom crystals of some replaced mineral found as inclusions in stilbite. ]Ti» 



Needles of natrolite which have penetrated areas of stilbite 171 



Renniants of scolecite needles in the midst of natrolite 1T:I 



Chart showing order of deposition and periods of stability of llie various 



primary and secondary minerals 171» 



^[ap of the coal basin of Decazeville 24*; 



vn 



