[ells] interesting PROBLEMS IN NEW BRUNSWICK GEOLOGY 25 



the river, and these were regarded as representing the basal beds of the 

 Cambrian in this direction. 



This westward extension of the supposed Kingston passed near the 

 village of St. George, and thence, south-westward, extended through 

 Letite peninsula, continuing on and forming most of the group known 

 as the Western isles. The rocks in this extension west of St. George 

 include schist, felsite, diabase, granite, squeezed eruptives, slate and con- 

 glomerate. As a whole, they may be classed as a highly metamorphic 

 series. They are thus in character not unlike much of the typical 

 Kingston of the St. John river. 



For some years it was supposed that the series as a whole belonged 

 to the Upper Silurian system, owing to the presence of fossils of that 

 age in some of the less altered portions. Ultimately, a,t the date of 

 publication of the map of Charlotte count)'', it was decided, chiefly on 

 lithological grounds, to place the whole group provisionally in the pre- 

 Cambrian, and to regard the fossiliferous Silurian as small infolded 

 areas. This decision applied to the rocks of Letite peninsula, as well 

 as to those of Deer and Campobello islands and those found along the 

 east side of Grand Manan. 



The rocks in this group are largely volcanic. They are also of 

 comparatively recent date instead of being pre-Cambrian. They cut 

 and alter limestone and shale, which are filled with Upper Silurian and 

 Devonian fossils. Owing to metamorphism certain jiortions of these 

 sediments are changed to schists of various kinds ; but even in parts of 

 these a careful search will sometimes reveal traces of organisms. iVs a 

 whole, therefore, this part of the Kingston group so-called, as developed 

 in Letite and in the Western isles, must be removed from the pre-Cam- 

 brian as coloured on the geological map, and classed as Upper Silurian 

 in part and in part as volcanic. 



An interesting locality in the Letite area as showing the degree of 

 alteration to which these sediments and volcanics have been subjected, 

 is near the light-house on Letite Head. Here the original Silurian 

 slates have been changed into hard felspathic schist, while the associated 

 masses of disabase have assimied the aspect of chloritic schist. Yet in 

 certain bands of slates associated with the former the traces of fossils 

 can be recognized, and are sometimes abundant, though frequently much 

 distorted. It was only by carefully tracing out the actual relations of 

 the fossil-bearing bands from their highly crystalline condition that 

 their true position as a part of the Upper Silurian was definitely 

 ascertained. 



There is, however, a belt of pre-Cambrian schists and associated 

 rocks in the south-eastern portion of Charlotte county, which extend^ 



