Thomsox. — Geology of Middle Waipara and Weka Pass District. 409 



boundaries of the Oamaruian overlap in North Canterbury, but transgress 

 these bounds in the lower Awatere Valley. Difierential earth-movements 

 during the Notocene must also be invoked to explain the facts of distribution 

 as well as those of the relationships of some of the superposed series of rocks. 



Marshall (1919) has combated my criticisms of his use of the term 

 " Oamaru " for his system, and, as the nomenclature of the younger rock- 

 series as a totality is a matter of considerable importance, it seems advisable 

 to critize further his reasons for wishing to retain the term. 



" 1. Historical : (a.) The locality is the one from which the first col- 

 lections of fossils in New Zealand was made." Actually the first fossils 

 mentioned in geological literature were those collected by Dieffenbach in 

 the Chatham Islands, and at East Cape, Parengarenga, Kawhai, and 

 Whangaroa. These were determined generically by Gray, as mentioned 

 in Diefienbach's Travels. Mantell also observed fossils in the Wanganui 

 district before he visited Oamaru. 



" (b.) Hutton's Oamaru sj'^stem included nearly all the strata in the 

 district, and his Oamaru system includes the majority of the rocks classed 

 in the Oamaru system by me. The retention of the name will serve to keep 

 alive the memory of the man who did so inuch spade-work in the palaeonto- 

 logy and stratigraphy of New Zealand." It is true that Hutton included 

 nearly all the rocks of the Oamaru district in his system, but he excluded 

 the Awamoa beds. His system did not include the Shag Point beds or the 

 Amuri limestone and underlying beds, which are included by Marshall. 

 If the Clarentian is also included by Marshall — and I fail to see how any 

 .consistent grounds can be found for excluding it — then in the Clarence 

 Valley area his Oamaru system will embrace more than seven times the 

 thickness of the beds which in that area correlate with Hutton's Oamaru 

 system.* Hutton's name Avill live for his spade-work in palaeontology and 

 his clear reasoning in stratigraphy without the retention of the Oamaru 

 system, and it is difficult to see how an extension of his system to embrace 

 the Waipara system can be considered otherwise than as a desire to forget 

 his memory, ^gince he spent nearly thirty years of his life in endeavouring to 

 secure recognition for his separation of the two systems. 



"3. In the Oamaru district there is a fuller development of the various 

 strata of a fossil-bearing nature than elsewhere." To establish this Marshall 

 includes in the Oamaru district the whole area between Shag Point and the 

 Waihao River, although it has hitherto included only the area between the 

 Kakanui and Waitaki Rivers. But, granting this, he quotes the Wharekuri, 

 Waihao greensands, and Bortonian as separate horizons, although it is more 

 than probable that they are about the same. The Oamaru district, thus 

 conceived, includes only Piri]3auan, Kaitangatan and Oamaruian rocks, 

 whereas the Waipara district includes all these together with the overhang 

 fossiliferous Greta beds (Waitotaran) and imfossiliferous Kowhai beds 

 (perhaps Castleclifiian), whUe the Clarence Valley possesses a still fuller 

 sequence. No single locality, however, has the complete sequence of the 

 younger rocks. 



Marshall has comitered by suggesting that " Notocene " should mean 

 either that this is the farthest southern point where such rocks have been 

 found or that the formation is common to southern latitudes. In science 

 a term takes the meaning its author gives to it, and my definition of 

 " Notocene " is perfectly explicit. 



* This is admitting the Clarentian as 3,000 ft., the Amuri limestone as 2,000 ft. 

 (both low estimates), and the Weka Pass stone and " grey marls " as 700 ft. (a liigh 

 estimate). 



