198 E. A. Daly — Secondary Origin of Certain Granites. 



rim of red rock, identical in all its properties with the kerato- 

 phyre. This suggests that the keratophyre itself may be of con- 

 tact origin." 



Finally : 



" The conclusion reached is that, in all probability, the kera- 

 tophyre is of contact origin — that is, it was produced by the 



PIGEON 



NNV 



v • 



-•- v. 



v ',j.:yj.".:v' 



. . v ... v ... v ... v ... v ... 1/ ■•_•-"-- V V V V V 



v v v"v V v v v'V'Y'W v'v V ~V V~~V~ ~V~~V~-~;;_l--~V~V~~V~~V~ V ~V V V V V V 



V V V V V V Avf V V V V V V V V -V V V V V ~ V V V V V V V V V V V V 



VVVVVVVVVVVVVVVVVVV'VVVVVVVVVVVVVV 



vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv 

 vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv 



vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv 

 vvvvvvvvvvvvvvvvvvvvvvvvvvv'vvvvvv 



V V V V V V V v_v v_vvv_vvvvvvvvv.vvvvvvvvvvv 



LAKE 



SUPER 



R 



SSE 



Fig. 4. Diagrammatic map of part of Pigeon Point, Minnesota, showing 

 general relations among the different rock formations; after Bavley. 



1. Animikie quartzites and slates. 2. Contact zone in the Animikie sedi- 

 mentaries. 3. Olivine gabbro. 4. Intermediate rock. 5. Soda granite and 

 keratophyre. Conventional sign for strike and dip. Scale : nine inches = 

 one mile. 



fusion of the slates and quartzites of the Animikie through the 

 action upon them of the * gabbro.' The magma thus formed 

 then acted in all respects like an intrusive magma. It penetrated 

 the surrounding rocks in the form of dikes, and solidified as a 

 soda-granite under certain circumstances, and under others as a 

 quartz-keratophyre."* 



^•Op. cit., p. 12. 



