300 



in great abundance, while about 25 to 50 feet lower down 

 there are many very large oblate spheroidal concretions. 

 This zone has a thickness of 405 feet (123 m.). 



Zone 4. — Grey and greenish grey impure limestones in 

 thick layers all of which are steeply upturned with many 

 of the beds beautifully ripple marked. Near the top they 

 are much disturbed and in some places the bedding has 

 been destroyed and the rocks reduced to breccia. Dal- 

 manella elegantula, Chonetes tenuistriatus and Cleidophorus 

 have been recognized. The estimated thickness of this 

 zone is 70 feet (21 m.). 



Moydart formation. — This formation introduces a change 

 in lithology, the dark shales giving way to impure lime- 

 stones and shales of some shade of grey. The change in 

 facies is paralleled by a change in fauna. The formation 

 ends on the top of the "Red Stratum." 



The fauna is especially characterized by the appearance 

 of Chonetes ftovascoticus and Spirifer suhsulcatus, these 

 two species taking the places of the earlier Chonetes ten- 

 uistriatus and Spirifer crispus. Other characteristic species 

 are Camarotoechia cf . formosa, a rhynchonelloid resembling 

 Eatonia medialis, Homeospira cf. acadica, H. cf. evax, 

 Pterinea emacerata, Grammysia cf. acadica, Diaphorostoma 

 niagarensis, and Homalonotus dawsoni. The thickness is 

 379 feet (115 m.)._ 



Zone I.- — Greenish grey, impure limestone in beds up to 

 four feet in thickness, interstratified with blue and grey 

 sandy shales. As a rule fossils are not common, but in 

 some limestone lenses they are present in great abundance. 

 They consist of large crinoid columns, thick stems of a 

 branching Monticuliporoid, Dalmanella elegantula, Cama- 

 rotoechia cf. formosa, a rhynchonelloid resembling Eatonia 

 medialis, Spirifer suhsulcatus, Homeospira cf. acadica, H. 

 cf. evax, Pterinea emacerata, Grammysia acadica, Cornulites 

 proprius, Serpulites cf. dissolutus, Orthoceras (two species), 

 Diaphorostoma cf. niagarensis, Calymene tuberculata, and 

 Homalonotus dawsoni. The zone ends at the base of the 

 "Red Stratum," and has a thickness of 347 feet (105 m.). 



Zone 2. — The "Red Stratum," consists of a brick red 

 shale of which the major portion has prismatic structure. 

 Little stratification is shown except near the base where 

 27 inches of thin beds of red limestone and shale are transi- 

 tional to the zone below. There is no transition to the 

 overlying green shale. About 20 feet (6 m.) below the 



