304 G~. S. Hume — Stratigraphy and Geological Relations 



is found can be taken as about the same stratigraphic 

 height in the two areas, then the lower beds of the Wabi 

 are equivalent to the top part of the Cataract. This 

 means that most of the Cataract of southwestern Ontario 

 is not represented in the Timiskaming area, where 75 feet 

 of deposits occur above the strata containing Zygobolbina 

 williamsi. 



The Wabi formation thus seems to belong to a trans- 

 gression of the sea from the Arctic which spread also over 

 the Hudson Bay district, Manitoba, eastern Saskatche- 

 wan, and south into eastern Wisconsin and northern Mich- 

 igan. It probably united in part with the southern inva- 

 sion of the sea at this time, but the slight intermingling 

 of faunas in the two basins of deposition is opposed to 

 any close connection between the two seas. 



Silurian: Lockport formation. — The Lockport is the 

 most extensive formation of the Lake Timiskaming area, 

 and consists of magnesian limestones about 186 feet thick. 

 It is separated at the base by a slight disconf ormity from 

 the top of the Wabi formation, and although this break 

 does not appear to be a great discordance, yet it repre- 

 sents the time of the Clinton and Rochester of New York. 



The Lockport begins with a layer of sandstone 1-2 feet 

 thick, but which very rapidly changes upwards into thin- 

 bedded magnesian limestones. The top portion is 

 marked by thicker bedded, more resistant strata which are 

 an approach to dolomites in composition. 



The fauna is marked by corals and cephalopods, 

 although brachiopods are also common in parts. Among 

 the more common fossils are: Caninia stokesi, Cyatho- 

 phyllum articulatum, Favosites favosus, F. g othlandicus , 

 F. liispidus, F. niagarensis, Halysites catenularia, H. 

 catenularia microporus, H. catenularia feildeni, H. labrin- 

 tliicus, Heliolites megastoma, Strombodes pentagonus, 

 Syringopora bifurcata, S. dalmani, S. verticellata, Cla- 

 throdictyon vesiculosum, Pentamerus oblongus, Ortliis 

 near davidsoni, Actinoceras backi, A. rotulatum, A. verte- 

 bratum, Discosorus conoideus, D. remotus, Huronia bigs- 

 byi, H. distinct a, H. minuens, H. obliqua, Orthoceras 

 alienum, 0. franldinense, Encrinurus ornatus, Calymene 

 niagarensis. 



These fossils show a striking similarity to those of the 

 Lockport of the Lake Huron district. Many of the corals 

 in the Timiskaming area have been reported by Williams 



