410 



QUICKSILVER DErOSITS OF THE PACIFIC SLOPE. 



kind run together and separate again, without, however, diverging at any 

 high angle.^ Plans of such groups of veins are shown in Fig. 19. 



Fig. 19. Linked \ 



horizontal section. 



In all cases these veins are linked together by direct continuations of 

 divergent strike or by small stringers intersecting the layers of rock Avliich 

 intervene between them. It appears to me convenient and natural to call 

 such systems linled veins, to distinguish them from .simple fissure veins and 

 parallel systems of veins on tlie one hand and from netted (or reticidated) 

 veins on the other. 



There are still other less usual groupings of veins which do not need 

 to be christened. No one would hesitate to speak of a system of veins 

 whicli radiated from a central point as radiating veins or of a vein which 

 sends off numerous sti'ingers into the country mck ns a l>ranching vein, 

 and such descriptive terms are clear and precise. 



Chambered veins — A sliglit degree of irregularity in the tenacifv of the 

 rocks or in the cliaracter of tlie rapturing force sutHces to produce linked 

 fissures instead of groups of parallel fissures. Greater variations in the 

 rock or a torsional stress accompanj'ing tlie dislocation will result in crush- 

 ing portions of the country rock adjacent to the main fissure This crush- 



' Either a group of veiii.s occnpyinL' fissiire.s of tlii.s description or .1 .system of par.illtl veins is calletl 

 in German a Gangziig, Imt tliis word, tliongli sliort and expressive, b.as no English eqnivalent and is 

 not readily transl.ited by any concise term. It mi'an.s a procession or a flight of veins. It might be 

 possible to introduce the term a school of veins, as we speak of a school of dsh, but the metaphor does 

 not seem particularly worth preserving. 



