168 



to the western end of the province, dividing the sedi- 

 mentary series into two parts, an eastern and a western. 

 In the eastern part of the field, some of the batholiths are 

 also quite extensive in area, others assume the form of 

 parallel bands a fraction of a mile wide and several miles 

 long, cutting the sedimentary rocks at slight angles. At 

 Liverpool bay, large granite dykes occur that also have a 

 tendency to follow the stratification planes. 



The composition and texture of the granite vary much 

 with the locality and mode of occurrence. The rock con- 

 sists for the most part of a light-grey or reddish-grey, coarse, 

 porphyritic, biotite-granite, generally studded with large 

 phenocrysts of white or pink-white feldspar. In the west, 

 a light pearl-grey or pinkish-white, fine-grained, muscovite- 

 granite occupies small areas penetrating the biotite-granite 

 as well as the sediments. With the muscovite-granite are 

 associated dykes of coarse pegmatite often passing to 

 quartz, and bearing a large variety of minerals. 



The granite is found everywhere to cut and penetrate 

 the sediments; it cuts also the anticlinal and synclinal folds, 

 and the interbedded quartz veins, without affecting in the 

 least their original structure. In the vicinity of the granite 

 the clastic rocks have been metamorphosed into gneisses 

 and schists, the degree of metamorphism being greatest 

 near the granite. The line of contact is sometimes sharply 

 defined, but generally there is apparently a gradual trans- 

 ition from slate and quartzite to granite which in many 

 cases is such as to suggest the assimilation of the intruded 

 rocks by the large subjacent igneous masses. Within the 

 granite areas are included large and small insular patches 

 of altered sediments whose original structure is apparently 

 not disturbed, and the granite itself often contains numer- 

 ous small inclusions of sedimentary rock partially absorbed. 



The granite intrusion took place during the Devonian 

 period; it affected the Nictaux-Torbrook rocks which are 

 placed at the base of the Devonian and it is on the other 

 hand overlain unconformably by the Horton series which 

 has been referred by some writers to late Devonian and 

 by others to Lower Carboniferous. 



BASIC INTRUSIVES. 



Basic intrusions, taking the forms of dykes and sills, 

 are found cutting the sediments, but they are confined 

 almost wholly to the western part of the field. In Kings 



