Speight. — Lower Waipara Gorge. 227 



the highest members of the sequence recorded above ; the other beds are, 

 however, in close proximity to the river on its eastern side. The former 

 will be referred to hereafter as the Pareora series, seeing that their fossil 

 fauna shows a close relationship to that of the typical Pareora locality. 



Structure and Arrangement op the Beds in the Gorge. 



(See map and section). 



At the junction of the Omihi Creek with the Waipara River the beds 

 consist of sands, sandy clays with concretionary bands, and conglomerates 

 with shells. The strike is N. 5° W., with a westerly dip of about 22 £°. 

 A good exposure is to be seen where a recent flood has removed the 

 surface covering of shingle, and laid bare the solid bank just opposite 

 the mouth of the Omihi Creek. In the Omihi itself, just above the 

 junction, the beds strike north-east and dip to the north-west at 45°. 

 It is evident that the strike here swings round somewhat, a feature which 

 will be readily understood when the general structural features of the 

 locality are considered later, this small movement being only a part of 

 one of wide extent. 



On following the river down from the junction, the high banks on 

 the east are found to be obscured by soil and slip-material, but after 

 going about 300 yards the dip observed at the junction changes to 

 the south-east, with the same strike as before. The structure is thus 

 anticlinal, and the same anticline can be distinctly traced for over a 



S 

 j» 





Pareora Series. Grey Marls. Pareora Series. Grey Marls. 



Fig. 2. — Section from Omihi Creek through Bill's Hill to Sea (Five Miles). 



mile to the north-east along the bank of Limestone Creek, a tributary 

 of the Omihi coming from the northern slopes of Mount Cass, the stream 

 having eroded a deep channel lor some distance along the axis of the 

 anticline. On going still further in that direction the underlying lime- 

 stones are exposed, with what has all the appearance of an anticlinal 

 arrangement. 



Following the banks of the Waipara further down, the south-easterly 

 dip is maintained till the second gully below the Omihi is reached. 

 At the head of this a well-marked syncline is exposed, the western side 

 being chiefly composed of thick beds of fine gravel, but overlying them 

 is a bed of coarse gravel with numerous molluscan remains. These 

 include Fvlguraria arabica, Ostrea nelsoniana, 0. ingens, 0. angasi, 

 Siphonalia dilatata, Paphia curta, Crepidida gregaria, Mactra elongata, 

 Ancilla hebera, Ancilla australis, and Chione intermedia. The syncline 

 here exposed can be traced to the north-east, parallel to the anticline 

 running up Limestone Creek. 



On going still further down-stream the beds dip to the west, and an 

 angle of about 60° is maintained for a distance down the river of about 

 two miles, the strike being between N. 25° E. and N. 35° E. The 

 beds are well exposed in the bluff just below the point where the road 

 from Glasnevin Railway-station meets the river. They consist of sands. 

 8* 



