The Grey loch Synclinorium. — Dale. 
scopic plications; (c) the gen- 
eral course of the quartz laminae 
whenever the}' can be clearly 
distinguished from those which 
lie in the cleavage planes. 
III. Cleavage-foliation may 
consist of: (a) planes produced 
b}' or coincident with the faulted 
limbs of the minute plications; 
{h) planes of fracture resem- 
bling joints on a very minute 
scale with or without faulting of 
the plications; (c) a cleavage 
approaching "slat}' cleavage" 
in which the axes of all the par- 
ticles have assumed either the 
direction of the cleavage or one 
forminga very acute angle to it 
and where stratification-foliation 
is no longer visible. 
IV. A secondary' cleavage 
resembling a minute jointing oc- 
curs in scattered localities. 
Y. The degree and direction 
of the pitch of a fold are indi- 
cated by those of the axes of the 
minor plications on its sides. 
"\'I. The strike of tlie stra- 
tification and cleavage-foliations 
often diflfer in the same rock and 
are then regarded as indicating 
a pitching fold. 
VII. Such a correspondence 
exists between the stratification 
and cleavage-foliations of the 
great folds and those of the 
minute plications that even very 
small specimens properl}' orients 
ed give in many cases the ke}- to 
the structure over a large part of 
the side of a great fold. * 
*Tlie full report will contain reproductions of nhotographs of slishtly enlarged 
rock sections, and also sketches and diagrams illustrating these principles. 
