106 NEW YORK STATE MUSEUM 



occur in the zone of massive gneiss they also are massive, although 

 the augite is usually granulated as the result of flowage (plate 4, 

 upper figure) ; where they occur in the protoclastic gneiss they are 

 granulated (plate 4, lower figure and plate 5, upper figure); and 

 where they are found in the cataclastic-protoclastic gneiss they are 

 more or less pulverized and have a gneissic character (plate 5, 

 lower figure). 



b In each of the three zones of metamorphism many cases may 

 be observed where the foliation of the inclosing gneiss also crosses 

 the intruding dike. This is particularly noticeable in the case of 

 the pegmatite or granitic veins in all three zones and of the hyperite 

 dikes in the crushed zones. 



c The outer zone of rock must have been partially crushed subse- 

 quently to its complete solidification, as shown by granulation of 

 the quartz. 



d The line of equal crushing or the boundary between protoclastic 

 and cataclastic-protoclastic gneiss is very regular in its trend and 

 passes directly across the banding and hence is independent of any 

 magma tic flowage. 



e On the Lowville quadrangle the planes of foliation alternately 

 pass several times from a low dip (30 ) to a vertical attitude and 

 then back again to 30 , going southwest. Miller reports this pseudo 

 anticlinal and synclinal effect to be repeated on the Port Leyden 

 quadrangle to the south. Where the banding northwest of Croghan 

 is observed in plan, there is a suggestion of a synclinal folded 

 structure. 



/ Miller has raised the objection that, if orogenic forces have 

 acted in this region, the Grenville gneisses should exhibit signs of 

 crushing. On the Lake Bonaparte quadrangle blocks of Grenville 

 which are associated with the syenite-granite gneiss complex are 

 crushed. It is true, however, that elsewhere they are uncrushed, 

 but for the very good reason that they have been entirely recrystal- 

 lized by contact metamorphism, or by the injection of pegmatite 

 veins, or by soaking with granitic juices which permeate them. The 

 granites responsible for this are younger than the syenite-granite 

 complex. 



14 The mere fact of foliation crossing both country rock and 

 associated dikes or pegmatite veins is not accepted as a uniformly 

 valid criterion for the dynamo-metamorphic or dynamic flow and 

 recrystallization origin of gneissic structure. In the broad band of 

 granite gneiss innumerable dikes of coarse pegmatite have been 

 observed which cut across the foliation of the gneiss and are them- 



