SOUTHER^ NEW BRUNSWICK. 23 ]) 



as the overlying Cambrian slates. No attempt has, however, been 

 made to separate them on the map from the other pre-Cambrian rocks, 

 as they are in many places so intimately associated as to render their 

 distinct delineation on so small a scale an impossibility. 



Diorites are found at various points throughout all the formations Diorite. 

 from the Laurentian to the Triassic inclusive. They are abundant in 

 the pre-Cambrian, especially in Division 5, the former Kingston, a 

 large portion of which is made up of apparently interbedded felsite 

 and fine-grained diorite. In some places the diorites are very coarsely 

 granular and contain much magnetic iron in grains, as at the Scotch 

 settlement, in northern Kings county, and on the Pollet River, south 

 of Elgin corner, in Albert county, typical diorites some of which are 

 almost black from the abundance of hornblende, are found at Mechanic 

 settlement post office and westward, while throughout the pre-Cam- 

 brian belt north of Quaco and elsewhere diorite and dioritic ash-rock, 

 with amygdaloid, are very frequent. It has, however, been thought 

 better not to attempt the separation of all the areas of these intrusive 

 rocks on so small a scale, as their exact limits cannot be determined 

 definitely from the unfavourable nature of the country. 



In the Lower Carboniferous also, rocks presumably of intrusive Carboniferous 



' L J and Tnassic 



character are found not only around the southern edge of the central intrusions. 

 Carboniferous basin, but at various scattered points of the basin itself. 

 They often obtrude through the generally flat beds of the Carbonifer- 

 ous in dome-shaped hills or ridges of dolerite, while felsitic ashes and 

 hard crystalline felsite also occur; the most prominent area of these 

 latter rocks is seen in the northern portions of Charlotte county, 

 whence they extend across into Sunbury. These intrusions were 

 probably not later than the middle of the Lower Carboniferous period. 

 In the Triassic also, as at Quaco, intrusions of trap similar to that 

 of the North Mountain range of Nova Scotia are seen breaking- 

 through the Lower Carboniferous limestones of the Head. The area 

 is, however, but small. A general description of the dioritic rocks 

 of the Lower Carboniferous is given in the report of 1872-73. 



ECONOMIC MINERALS. 



A full account of the economic minerals of the southern part of 

 the province was given in the report of 1870-71, in so far as they 

 were known at that time. Since then discoveries of more or less 

 importance have been made, but nothing of any special value has been 

 met with. 



