Tnoiisox. — Geology of Middle Waipara and Weka Pass District. 335 



GENERAL ACCOUNT OF THE GEOLOGY AND PHYSIOGRAPHY. 



As in all districts where any development of the Notocene is present, 

 there are three main classes of rocks, viz. :— 



(1.) Pre-Notocene : in this case greywackes and argiUites, strongly 



folded, indurated, and jointed, and truncated by an erosion 



surface, on which rests unconformably — 

 (2.) Notocene (as in Table III below) : the rocks are only moderately 



indurated, and then well jointed, but are not in all cases cemented ; 



they are for the most part strongly tilted, only locally folded, 



and are often faulted. 

 (3.) Notopleistocene : horizontal, for the most part unconsolidated, 



terrace and river silts and gravels. 

 The main subdivisions of the Notocene are shown in Table III. 



Table III. — General Classification of the Notocene Rocks of the District. 



Oamaruian 



Mount Brown beds 



Rubbly impure Mmestones and< calcareous 

 sandstones, interbedded with sands. 



Grev marls " . 



Grey calcareous and sandy mudstones, 

 sandstones, and sands. 



Weka Pass stone and Weka 

 Pass greensand 



Limestone and calcareous sandstone, pass- 

 ing dowTi into a calcareous greensand 

 with phosphatic nodules. ♦ 



