Cretaceo- Tertiary of New Zealand. 496 



geologists as Sir James Hector, Mr. Alexander McKay, Sir Julius 

 von Haast, and Professor Cox had no misgivings on this point when 

 mapping the Shag Point district. 



In his reference to tlie Kaitangata district in South Otago 

 Dr. Marshall' says that since no actual contact of the Lower Tertiary 

 and Cretaceous formations are seen, " obviously this unconformity 

 is a matter of inference." But the unconformity cannot be so lightly 

 disposed of as this. When dealing with the Shag Point section he 

 has also, as we have seen, laid great stress on this contention that 

 there is no visible contact. He fails to realize (a) that visible 

 contacts between different formations are not the rule, but the 

 exception ; and (h) that a field-geologist has no difficulty in 

 delineating the distribution of two formations that are petro- 

 graphically and palseontologically different, more especially when 

 the general arrangement of the strata comprising the formations lends 

 its powerful assistance. The Kaitangata and Tertiary coal-bearing 

 formations differ as widely as the proverbial chalk and cheese, as 

 may be seen by a perusal of the following tabulated statement : — 

 Tertiary Formation. Kaitangata (Cretaceous) Series. 



(a) Limestone (glauconitic) . (a) Compact sandstones and shales. 



(6) Hard limestone. ' (6) Hard greywacke conglomerates with 



numerous seams of superior bright- 

 brown coal, 

 (c) Glauconitic sands. (c) Brown sandstones with calcareous 



horizon containing marine shells. 

 {d) Quartzose sands and con- {d) Thick bands of quartzose conglomerate 

 glomerate with lignite seam. and quartzose sands with seam of 



lignite. 



The Kaitangata Series, which is bent into folds, rests directly on 

 a highly eroded surface of the altered greywacke and slaty shales of 

 the Kakanuian (Older Palaeozoic) and mica-schists of the Maniototian ; 

 while the Tertiary Series, which is horizontal, lies in some places 

 on the Kakanuian, in others wraps round the boundaries of the 

 Kaitangata Beds in a way that clearly indicates unconformity, not- 

 withstanding that the actual junction is obscured by glacial drifts 

 and clays. 



The Cretaceous Series contains two coal horizons, namely, a lower 

 consisting of quartzose conglomerates and sands with one seam of 

 lignite, and an upper consisting of massive bands of greywacke 

 conglomerate containing many seams of hard bright coal. 



The Tertiary beds contain a rich fauna that is distinctively 

 Oamaruian. The Kaitangata marine horizon, which lies between the 

 two terrestrial stages, contains Concliothyra parasitica^ a peculiarly 

 distinctive Cretaceous form, a new Turritella {T. semiconcava), 

 Belemnites lindsayi, and a rich assemblage of undescribed mollusca 

 that possess a facies resembling the fauna underlying the hydraulic 

 (Amuri) limestone and overlying the coal at Kawa-Kawa in North 

 Auckland. The point at issue is not so much one of conformity 

 or unconformity as the more immediate one that if the overlap 

 hypothesis be true the Cretaceous fauna ought not to exist in Otago. 



' Geol. Mag., July, 1912, p. 318. 



