f^28 Transactions. 



did not distinguish between the latter rock and the Weka Pass stone. The 

 succeeding " grey marls " he considered as strongly vmconformable to the 

 underlying groups, and so showed them on his map ; but, as Hutton pointed 

 out in 1877, he failed to recognize the strong fault crossing Boby's Creek, 

 which brings the niiddle Notocene against the older Notocene. Von Haast's 

 map shows three inliers of the pre-Notocene within the Notocene of the 

 Boby's Creek watershed, and these he considered as islands in a large pre- 

 Notocene bay, along the shores and round the small islands of which the 

 lower strata were first deposited in shallow water. His map also shows in 

 approximately correct position a small detached outcrop of calcareous sands 

 (Amuri limestone) in the upper part of Boby's Creek, which has escaped 

 notice by all subsequent observers. In his next account of the district. 

 in 1879, von Haast still adhered to an unconformity between the lower 

 Waipara (Cretaceo-Tertiary) formation and the "grey marls" forming the 

 base of the Oamaru (Upper Eocene) formation. ^ 



Hutton in 1877 referred to the district in a general account of the 

 geology of the north-east part of the South Island, and, as in his later 

 writings, dealt summarily with the beds below the Amuri limestone, but 

 emphasized the importance of the contact* between the Amuri limestone 

 and Weka Pass stone, which in his opinion unconformably separated a 

 lower — Waipara (Upper Cretaceous) — formation from> an upper — Oamaru 

 (Eocene) — formation. He first introduced the term " Amuri limestone," and 

 considered that this rock was consolidated, jointed, and water-worn before 

 the Weka Pass stone was deposited upon it. As already mentioned, Hutton 

 correctly interpreted the fault in Boby's Creek, and described another in 

 the upper part of the Weka Pass. Like Hector and von Haast, he con- 

 sidered that the Notocene rocks were deposited in valleys formed in the 

 pre-Notocene (" Lower Cretaceous "). 



McKay in 1877 (1877a) was successful in finding a saurian in the green- 

 sands between the " saurian beds " and the Amuri limestone. As regards 

 the unconformities believed by Hutton and von Haast to exist, he stated 

 that stratigraphically he could find no conclusive evidence of unconformity 

 between the Weka Pass calcareous greensands (base of the Weka Pass 

 stone) and the Ami|ri limestone ; and " if the Weka Pass calcareous green- ' 

 sands belong to the lower Waipara beds, no unconformity can be conceded 

 as far as the uppermost beds of the Mount Brown series." McKay at this 

 date was therefore in substantial agreement with the position taken later 

 by Park in 1888, and by Marshall, Speight, and Cotton in 1911. 



In the same year (1877b) McKay gave a detailed account of the 

 " reptilian " beds of Amuri Bluff and the Middle Waipara, and discussed 

 the question of the pre-Notocene physiography. He concluded that it was 

 improbable that the outlines of the present configuration of the area within 

 which the Notocene remnants are found was determined in the pre-Notocene, 

 or that the Notocene was deposited in a large bay, with inlets penetrating 

 the mountain-ranges, but that the evidence pointed to the subsidence of a 

 very wide area until deep-sea deposits were formed, and a subsequent 

 upheaval of mountain-chains, between which, and in the folds of which, 

 the younger rocks have been preserved to the present day. The views 

 thus early put forward by McKay, though receiving little attention at the 



* It is customary to term this contact the " junction " between these two rocks ; 

 but a junction is that which unites, whereas in the belief of many writers this surface 

 of contact or touching is rather a surface of separation. The term " junction " has 

 probably been adopted because there is practically a passage-zone and not a surface 

 of separation, the zone consisting partly of Amuri limestone with intercalations of 

 greensand and often with, borings filled with greensand, and partly of greensand con- 

 taining small pieces of Amuri limestone. v 



