290 THE STRUCTURE AND SUCCESSION AT 



Location of field. — The territory covered by the study lies 

 along the nortliAvest side of Sydney harbor. It extends from 

 the month of Leitch's creek on the west, through ISTorth Sydney 

 and Sydney Mines on the east, to Cranberry Head ; thence north- 

 west along the shore of Spanish bay to the entrance of Big pond ; 

 thenoe southwest to Sawmill lake, and to the Intercolonial rail- 

 way track where it crosses. It thus embraces roughly an area 

 ten miles by two. 



General stratigraphy. — The strata belong wholly to the Car- 

 boniferous period ; lying on the northwest side of an anticline of 

 these rocks which runs northeast from the pre-Cambrian of 

 George's river end of the Coxheath hills, and plunges northeast 

 as well. 



This fold dies out in Sydney harbor ; and its strata on the 

 north leg change as one goes eastward, from a normal northeast 

 gradually to an east-west and finally a northwest strike. At 

 the extreme east side of the extension of the fold, there arises 

 an imperfect synclinal basin, containing the coal seams of 

 Sydney Mines, and freeing the strike of the beds from any 

 influence of the anticline. 



From the west end of the field studied, and beyond, east- 

 ward one and one-half miles to Limestone creek, the strata have 

 been considered as belonging to the Lower Carboniferous lime- 

 stone, equivalent to the Windsor series of Fletcher, on the main- 

 land. From Limestone creek to Stubbart point, about six miles, 

 has heretofore been mapped as Millstoane Grit [vide Brown; 

 also Geol. Surv. Can., No. 653, Sydney sheet, 134]. The 

 boundary between this and tlie overlying Coal Measures, which 

 extend thence eastward to the ocean at Cranberry Head, about 

 four miles, is very arbitrary as it has been defined up to tht 

 present. 



Topography. — The surface of the land presents little marked 

 topographic variation. That underlain by the Windsor series 

 is low for tlie most part. W^hile the same series on the 

 peninsula to the south, lying between the two arms of Sydney 



