130 

 DETAILED DESCRIPTION OF SECTIONS. 



For a general description of the geology along the 

 line of the railway between Toronto and Hamilton see 

 the guide book for Excursion A 12. 



From Hamilton to Grimsby, the railway traverses 

 a fertile plain underlain by the red shales of the Queenston 

 formation (Ordovician). This region forms part of a 

 celebrated belt of fruit lands extending from the Niagara 

 river to Hamilton. 



Section at Grimsby. 



The valley of Forty Mile creek at Grimsby presents 

 one of the best sections to be seen along the face of the 

 cuesta. 



The following table indicates in descending order the 

 thickness of the various layers: — 



1 — Lockport dolomite 



2 — Rochester shale 



3 — Clinton thick bed 



4 — Clinton thin beds with 

 „5 — Pentamerus zone at the base 



~"^-i_6— Medina grey band 



_ i l 7 — Medina mottled sandstone 



and shale 



r~8 — Cataract shale and lime- 



( stone 



Thickness. 

 Feet. Metres. 



Elevation. 

 Feet. Metres. 



12 3-6 

 45 13-7 



4 1-2 



10 3-0 



576 

 564 

 519 

 515 



175 

 171-4 



x 57-7 

 !56-5 



5 i-5 



505 



153-5 



20 6-o 



500 



152-0 



74 22-6 



6 1-8 



480 

 406 

 400 

 287 



146-0 

 123-4 



I2I-6 



87-2 



9 — Basal Cataract sandstone . . 

 10 — Red Richmond shales.... 

 Grimsby station... 



I. Lockport Dolomite. — The Lockport dolomite, as 

 exposed near the head of the ravine at Grimsby, consists 

 of heavy-bedded stone; but on the sides of the ravine, 

 nearer the face of the cuesta, a thin-bedded transition zone 

 of about eight feet (2-4 m.) occurs between it and the 

 Rochester shale. The dolomite is not highly fossiliferous 

 at this point but it nevertheless yields some characteristic 

 Niagara species. Brachiopods are by far the most abundant 

 organisms: the following species may be obtained: — 



Atrypa reticularis (Linn.) 



Atrypa nodostriata Hall 



Camarotoechia neglecta (Hall) 



