64 Harris and Crawford : 



an eight or nine inch band of grit, then two feet of shale, and 

 finally massive grits. 



The section is inconclusive on account of the absence of typi- 

 cal beds immediately to the east. The shales of this cliff are 

 certainly Upper Ordovician. It is our opinion that all the rocks 

 exposed belong to the Riddell Grits. If this be so, the Riddell 

 Grits would appear to be Upper Ordovician also, nor would the 

 position be altered if it should later be proved possible to separate 

 the shales from the Grit series. As to what lies above the Grits 

 we have here no evidence. 



Further up the creek, Dicranograptus shales form a steep bluff, 

 and after another break, we again find Grits interbedded with 

 rubbly shales, with an occasional Diplograptus. Sandstones along 

 this part of the creek also seem to belong to the Grits. 



As this is perhaps the most accessible, and one of the most 

 critical localities for the relations of Grits and Upper Ordovi- 

 cian shales the following references to QS. 6 SE. are given: — 



The " arenaceous and micaceous light coloured shales and 

 thin-bedded sandstones, 65-70°W, 25°S.," near the mouth of a 

 small eastern tributary are Dicranograptus shales. 



The bed rock across which this note is printed on the Quarter 

 Sheet is Riddell Grit. 



The " shales 80°W., 10°S." are Upper Ordovician, as are also^ 

 the " cream-coloured and bluish-grey thin laminated shales and 

 sandstones," further north. 



The " bluish-grey and light coloured shales, middle bed sand- 

 stone, 75°E., 15°N.," are those just described in detail. The 

 middle bed is Grit, and the eastern Grit band should be shown 

 above the first letters of " sandstone." 



The " bluish-grey shales 50°E., 5°N." are Dicranograptus- 

 shales. 



The " coarse, quartzose grit, E. 30°N. and E. 40°N.," are the 

 Grits referred to as interbedded with rubbly Diplograptus shales. 



Grits occur also near the western limit of the bed rock area. 

 shown. The section is not continuous, as would be inferred 

 from the Quarter Sheet, for between the various outcrops the 

 bed rock is obscured by basalt or the wash from it. 



The " white sandstone E. 65°S." is interstratified with car- 

 bonaceous shales, which yielded — 



Diplograptus, sp. % 



Climacograptus bicornis, J. Hall. 





