56 



south-eastern portions of the county, where they are ex- 

 posed in ravines and water courses, and uncovered in 

 quarries. 



B. The North Shore Cliffs. 



North of the mouth of Eighteen Mile Creek, there are five 

 sections, which are of sufficient importance to require 

 separate and detailed descriptions. 



THE IDLE WOOD CLIFF. 



Plate XXII. 



This section extends from the mouth of Eighteen Mile 

 Creek northward to the old drift-filled gorge noted above. 

 The cliff is usually steep, but much weathered, and many 

 places are thicklv overgrown by vegetation. The beach at 

 the foot of the cliff is very broad, and the waves ordinarily 

 do not reach the cliff. In consequence, a strong talus 

 has accumulated at the foot of the cliff, thus obscuring 

 many of the lower strata. 



At Idlewood, the cliff has a total height of something over 

 sixtv feet. At the top, six feet of the Moscow shales are 

 exposed, these therefore, including the whole ol the shale 

 bearing the Spirifer consobrinus fauna. If care is taken to 

 collect all the fossils when excavations are made, prepara- 

 torv to the erection of new cottages, a most complete series 

 of specimens of this fauna may be obtained. The natural 

 exposures in this cliff are such, that the Moscow shales can 

 not be readily examined. The Encrinal limestone is exposed 

 in the cliff at Idlewood, its average thickness being one foot 

 and a half. It may be traced for some distance northward, 

 after which it is not seen again until near the northern end 

 of the next section. The ealeareo-argillaceous layer first 

 noticed at the upper end of Section 8 in Eighteen Mile 

 Creek, forms a prominent band on the face of the cliff, ten or 

 twelve feet above the base. About seven feet above it, the 

 Modiomorpha subalata bed is seen, forming a distinct band 

 one inch wide, on the cliff. At the base of the cliff the three 



