264 PEOCEEMNGS OP THE GEOLOGICAL SOCIETY. [April 28, 



S. 35° W. Other less strongly-marked striae varied slightly from 

 this common direction. 



On the road from Belleville to ShannonvDIe, on the first conces- 

 sion of Thurlow, between Lots 24 and 25, I have observed the 

 direction of ice-marks on the outcropping Trenton limestone to be 

 E. 85° N. and W. 85° S. 



A careful study of the deposits here grouped together as " drift " 

 would apparently lead to the conclusion that their formation is re- 

 ferable to the action of two distinct agencies — the one a force 

 similar to that of land -ice pushing before it an accumulation of 

 northern rocks, whilst it rounded, polished and grooved the country 

 over which it swept, and the other an action similar to that of ice- 

 bergs scattering their freight of gravel and angular fragments of rock 

 over the bed of the sea. The eastern half of the township of Hun- 

 gerford, and the northern ranges of Huntingdon and Rawdon, are 

 thus covered with scattered angular blocks of limestone removed 

 from the Laurentian area, some of the blocks exhibiting distinct 

 glacial markings. Between the period of glacier ice and that of 

 floating ice the stratified sands and clays appear to have been depo- 

 sited in comparatively tranquil water. 



3. Lower Silurian. — In the South Riding of Hastings is an ex- 

 tensive development of that division of the Lower Silurian formation 

 distinguished as the Trenton group, including under that name not 

 only the Trenton Limestone proper, but also the Bird's-eye and 

 Black-River Limestones. The upper portion of the Trenton group 

 consists of a series of thin-bedded shaly limestones, occasionally in- 

 terstratified with beds of calcareous clay, and highly charged with 

 the characteristic fossils of the Trenton Limestone. These rocks 

 generally strike in an east and west direction, and are for the most 

 part horizontally bedded, or have only a gentle dip to the south-west, 

 with occasional evidence of a slight upheaval. In the shallow 

 valleys of denudation which in many places intersect the county, 

 sections of these limestones are occasionally exposed ; but as a rule 

 they are almost completely obscured by a covering of drift. 



The thin -bedded fossiliferous Trenton Limestones rest conformably 

 upon a thick-bedded limestone almost destitute of fossils, only three^ 

 species having hitherto been detected. Probably this thick-bedded 

 limestone represents the Bird's-eye and Black-River series. Sections 

 are exposed along an escarpment, varying from 50 to 100 feet in 

 height, which forms the junction of the Trenton beds with the un- 

 derlying Laurentian rocks. This escarpment gives direction to the 

 drainage from the Laurentian watershed of this part of Canada. 



The total thickness of the Trenton Limestone at Belleville may be 

 estimated at about 800 feet. A boring to the depth of 600 feet was 

 sunk about 15 miles S. W. of Belleville, in the County of Prince 

 Edward, without reaching the base of the series ; and another 

 boring, 7 miles north of Belleville, 500 feet deep, was attended with 

 a similar result. 



Whilst the Trenton group of rocks is almost confined to the 

 southern part of the county, it is notable that two large outliers of 



