THE PALMER (rNKlSSES. 211 



the otlier componL'iits. Between the fragments of shattered <[uartzes are 

 veins of the same mosaic, and these are often completely changed to 

 sericite and kaolin. Secondary microcline is not so common a constitnent 

 in these granitoid gneisses as it is in the corresponding rocks of the 

 Northern Complex, altiiongli it is present, while secondary albite appears 

 to be more common. 



The microscopic features of the granites of the Southern Complex are 

 thus similar to those of the northern area. Both rocks are composed of 

 the same minerals, and both have become gneissoid in places through 

 the influence of pressure. The southern rocks appear t<.) be jnore altered 

 than the northern ones, but they seem to have been the same originally. 



THE PALMER GNEISSES. 



The Palmer gneisses comprehend a variety of highly schistose rocks 

 of a gray, white, pink, or light-green color, showing little lenticular "eyes" 

 of qiuirtz in a " hy di'omicaceous " groundmass that appears to have been 

 nuich mashed. When the quartz is in excess the rocks resemble squeezed 

 cherts or quartzites, and when the matrix predominates they resemble fine- 

 grained gneisses. 



RELATIONS TO ADJACENT FORMATIONS. 



These rocks have already been mentioned as forming a distinct belt 

 between the granites and the sedimentary beds in the vicinity of Palmer 

 (Atlas Sheet XXXII). They are found also as isolated ledges at intervals 

 as far w^est as Champion, always between well-defined granites to the south 

 of them and undoubted beds of the Marquette series to the north. 



The relations of the gneisses to the surrounding rocks are not always 

 (dear. At no place are the gneisses seen to grade into the granites, although 

 the general similarity of the two rocks in their macroscopic features is strik- 

 ingly noticeable. A small topographic break usually intervenes between 

 these ledges that are nearest to each other, and in this interval it is thought 

 gradation phases may actually exist. 



With respect to the Marquette beds the relations of the gneisses differ. 

 In sees. 34 and 35, T. 47 N., R. 26 W., the schists are unconformably 



