63 



In addition to these relatively fine-grained varieties, 

 there are several fine exposures of nepheline syenite 

 pegmatites holding calcite. 



Annotated Guide — continued. 



Leaving this occurrence of nepheline rocks, 

 the party will continue westward to Hadley, 

 visiting en route a quarry in a fine-grained 

 microcline granite on the line between lots 7 

 and 8, Cons. VII and VIII of the Township of 

 Monmouth, from which paving sets are being 

 taken. 

 351-97 m. Hadley, Alt. 1,120 ft. (341 -4 m.) — The party 

 566-4 km. will again entrain at this railway crossing. 

 Following Burnt river, there are only a few 

 exposures before reaching Gooderham. 

 355-57 m. Gooderham, Alt. 1,023 ft. (342-3 m.)— The 

 573-8 km. railroad first crosses the Grenville limestone 

 with an intrusion of nepheline syenite and then 

 runs close to the contact of the limestone series 

 with the Glamorgan granite batholith to Max- 

 well's Crossing. 

 361 -21 m. Maxwell's Crossing. Alt. 1,023 ft. (34 2- 3 m ) 

 581-4 km. — In the rock cuttings on the railway at this 

 place, certain characteristic contact phenomena 

 of the intrusion of the Grenville limestones by 

 the Glamorgan granite batholith are well seen. 



Contact Phenomena in the Vicinity of Maxwell's 

 Crossing. 



The limestones are part of the south-western extension 

 of the great belt which underlies the north-west corner of 

 Monmouth and the eastern part of Glamorgan townships. 

 The granite belongs to a great batholith which extends 

 northward and westward into Dysart and Snowdon town- 

 ships. The invading granite, in the form of apophyses, 

 wanders through the limestone series in all directions, 

 sometimes cutting across the bedding, but very frequently 

 in the form of narrow dykes forcing its way between the 

 beds of the invaded limestone, changing it into amphibolite 

 and presenting a typical instance of lit-par-lit injection. 

 The granite, furthermore, not only penetrates the series, 



