the Horton-Windsor District, N. S. 155 



Particular pleasure was derived, and benefit received, 

 from direct field observations on the rocks and contained 

 faunas of Lower Carboniferous age in the vicinity of Set- 

 tle, Yorkshire, and in Westmoreland, under the able guid- 

 ance of Professor E. J. Garwood, of University College, 

 London, who at the sacrifice of his own pressing affairs 

 cordially exerted himself in the writer ^s behalf. 



Location. — The town of Windsor lies on the estuary of 

 the Avon river some 35 miles in a direct line northwest of 

 Halifax. The district under discussion embraces land 

 with an area! extent of 240 square miles on either side of 

 the estuary and facing north on Minas basin, the south- 

 ernmost prolongation of the headwaters of the Bay of 

 Fundy. Communications are readily effected with Hali- 

 fax, Yarmouth, and St. John by means of the Canadian 

 Pacific Railway. 



General Geological Relations. 



P re-Mis sis sippian history. — The Mississippian rocks in 

 the district form an undulating lowland with elevations of 

 less than 250 feet, margined on the west and south by an 

 upland of older crystalline rocks that is peneplaned at an 

 elevation of about 500 feet. The sediments of the upland 

 are intensely folded and regionally metamorphosed, with 

 a cleavage at a high angle to the south, and are intruded 

 by an unaltered batholithic mass of coarse, porphyritic, 

 biotite granodiorite. The altered strata are chiefly dark 

 green, pyritized, banded slates, belonging to the gold- 

 bearing or Meguma series of Nova Scotia, generally ac- 

 cepted as of late Proterozoic or Algonkian age, associated 

 south of the Gaspereau valley with a marginal strip of 

 slates and argillites of Niagaran age which have yielded 

 Dictyonema retiforme (Hall). The contact between the 

 two slate formations in the Windsor district is the result 

 of pre-Mississippian faulting, with upthrow on the south, 

 but farther to the west in the Kentville district, a larger 

 mass of Silurian rock is said to follow the Precambrian 

 slates without angular discordance. 



The erogenic disturbance, with granitic intrusion as an 

 end phase, that produced the folding and regional meta- 

 morphism of these rocks, affected elsewhere sediments of 

 Oriskany age and represents the outstanding historic 

 event of the whole region. It was named many years ago 



