INTRODUCTION. 



The remarks contained in the introduction to the 

 guide book for Excursion B3 are equally applicable to the 

 section at Credit Forks. In fact the sections at Hamilton 

 and at the Forks of the Credit are both essential to an 

 understanding of the formations exposed along the face 

 of the Niagara cuesta. For the correlation of these sections 

 and for the necessary general information the reader is 

 referred to the guide book for Excursion B3. 



ANNOTATED GUIDE. 



Iroquois Beach. 



Miles and 

 Kilometres. 



Toronto On leaving the city, the 



o. m. Alt. 254 ft. railway traverses a flat area 



o. km. 77.2 m. covered with post-glacial 



sands showing evidence of 

 wind action. At Lambton, the shore of the 

 post-glacial Lake Iroquois is 

 6.7 m. Lambton visible to the north, where 



10.7 km. Alt. 399 ft. excavations have been made 

 1 2 1. 3m. in the characteristic gravel 

 bars of the ancient beach. 

 On crossing the Humber river, good expo- 

 sures of the Lorraine shales may be seen in 

 the scarped banks of the stream. The 

 Humbervale quarry near here has yielded 

 many excellent examples of the large trilobite, 

 Isotelus maximus, Locke. Further expo- 

 sures of the Lorraine shales occur in the valley 

 of Mimico river a short distance beyond the 

 Humber. 



At this point the railway 

 14.4 m. Cooksville approaches so close to the 

 23 km. Alt. 391 ft. Iroquois beach that expo- 

 11 8. 8 m. sures of the gravel bars may 

 be seen from the train. Just 

 beyond Cooksville, the beach is ascended and 

 a more rolling aspect is presented by the 

 surface of the country owing to less modifi- 

 cation of the glacial accumulations by post- 

 glacial agencies. 



