THE UPPER SLATE MEMBER. 345 



♦tguizc, tor the grains ot" quartz always remain in tlieir entirety. It may 

 be, and indeed nsually is, the c-ase tliat they have undergone a second growth 

 and have thus become anguhir; })ut generally the original cores are easily 

 discovered. In tlie nearly piu'e feldspar sediments, upon the other hand, 

 when the feldspar has changed to other minerals, it is more dithcult, and, 

 taking a specimen of the most crystalline mica-schist 1)\- itself, impossible 

 to make out the oiijifinal fragmental cliaracter of the rock. 



5. The more crystalline mica-schists are derived from nearly pure 

 arkoses and in all cases the resultant schists are much liner grained than 

 were the oinginal sediments, for from each fragment of feldspar there has 

 been produced several or many individuals of mica and quartz. 



6. The material for the Upper slate has been derived from the Southern 

 Complex, and there is a direct connection between the character of the 

 rocks to the south and those of the slate belt adjacent. The greater 

 part of the belt has received its material in part from the granitic and in 

 part from the schistose areas ; while the part of the belt west of Penokee 

 gap has received nearly all of its material from the syeuitic granite to the 

 south and west. 



