Uttlet. — Geology of the Neighbourhood of Kakanui. 21 



The breccia dips S. 60^ W. at an angle of 8"^, but the upper beds 

 gradually flatten and the blue clay becomes almost horizontal. 



The limestone is rather fine in texture, and contains cleavage fragments 

 of minerals similar to those in the underlying breccia, but the junction 

 appears quite conformable. In its upper portion' the limestone becomes 

 glauconitic, and gradually assumes the character of bed c. The fossils 

 obtained from the base of the limestone were : Aetheia gauUeri (Morris), 

 Hemiihyris cf. H. squamosa (Hutt.), Terebratulina suessi (Hutt.), Epitonium 

 rugulosum lyratum (Zittel). Sharks' teeth occur in abundance at the base. 



The concretionary greensand (c) marks the change of conditions on 

 the sea-bottom which brought about the deposition of the more glauconitic 

 beds above. It is essentially a mixture of limestone and greensand, and 

 where it forms the present sea-beach the waves have removed the looser 

 sands and the surface is irregular and nodular. Minerals that occur in the 

 breccia are still present here, though sparingly. Fossils are abundant, 

 but, unfortunately, mainly as casts, and this has rendered specific identifi- 

 cation difficult. The following were obtained here : *Turbo sp., *Struthio- 

 laria sp., *Polinices ovatus (Hutt.) ?, *Cypraea ovulatella Tate 1, Epitonium 

 rugulosum lyratum (Zittel), *Siphonalia sp. nov., *Lapparia corrugata (Hutt.) ?, 

 *Etithria media (Hutt.), Pecten jwlymorphoides Zittel, Limalima (L.), Aetheia 

 gaulteri (Morris), *Hemithyris cf. H. squamosa (Hutt.), Terebratulina suessi 

 (Hutt.), Terebratula oamarutica Boehm, "^Terebratula sp. nov. 



Beds d and e are glauconitic greensands 10 ft. thick, but they have 

 been separated, as the upper band (e) is very much indurated, and does 

 not contain the same variety of fossils as bed d. I obtained the follow- 

 ing fossils from the lower greensand : Epitonium browni (Zittel), Aetheia 

 gaulteri (Morris), *Hemithyris cf. H. squamosa (Hutt.), Terebratula sp. 



Two forms which are verv abundant both in the concretionarv green- 



^ I/O 



sand and in the lower portion of the greensand {d) are Mopsea hamiltoni 

 (Thomson) and I sis dactyla Ten. -Woods. 



The hardened band (e) contains Pachymagas parki (Hutt.). 



The blue clay (f) is not very fossiliferous in its lower portions, but higher 

 in the section a number of fossils were obtained which would seem to 

 correlate the bed with the Awamoa horizon. Although the change from 

 the greensands below is very gradual, the exposure of / farther along the 

 beach clearly shows that the bed is lithologically similar to the blue clav 

 of the Awamoa Creek deposits. A list of fossils from bed / collected bv 

 Professor Marshall and myself has been published by Professor Marshall 

 in the last volume of the " Transactions of the New Zealand Institute " 

 (vol. 47, p. 384). 



It will be seen from the above description that there is a gradual tran- 

 sition from the limestone through greensands to the typical Awamoa blue 

 clay, and that the beds are conformable throughout. The horizons b. 

 c, d, e, and / are clearly recognizable in many other parts of the district. 

 The limestone is probably only the upper portion of the Ototara limestone, 

 the continuous deposition of which was interrupted by volcanic action 

 which resulted in the accumulation of the mineral breccias at Kakanui, 

 the volcanic rocks of Oamaru Creek, and much of Oamani Cape. 



(2.) Kakanui River {Right Bank). 



Thomson (1906, pp. 485, 486, fig. 2) has given a section of the beds exposed 

 here. In the bed of the river at very low water a small isolated outcrop 



