Vol. 65.] AND MAGNESIAN ROCKS OF NEW ZEALAND. 353 



Relations. — The correlation of these different exposures into a 

 petrographic province the members of which are approximately 

 contemporaneous is, in the present state of our knowledge, some- 

 what premature, although it is generally agreed that the occurrences 

 extendiug from D'Urville Island to the south of Lake Wakatipu 

 comprise such a unit. The exact relations of the Milford Sound 

 group are still sub judice ; while the inclusion with the rest, of the 

 Collingwood and Gibbston occurrences, is purely arbitrary. The 

 evidence for the contemporaneity of all these intrusions will be 

 summed up later. At present it may be pointed out that the case 

 for contemporaueity rests on petrographic similarity ; on the linear 

 distribution of the whole series ; and on the fact that, wherever 

 carefully examined, the rocks are found to be intrusive into 

 Mesozoic and Palaeozoic sedimentaries, although these sedimentaries 

 vary considerably in age. 



Previous Geological Work. 



The first worker on these rocks was Dr. F. von Hochstetter, 

 who, in 1859, examined the rocks of the Dun Mountain district, 

 Nelson [l]. 1 Then followed Sir James Hector, whose explorations 

 in the western Sounds in 1863 made known the locality of 

 bowenite [2]. Since then the peridotites and serpentines in various 

 districts have been located during the reconnaissance-surveys of Prof. 

 James Park in Collingwood County [3] and North- Western Otago [4], 

 of Prof. S. H. Cox in the upper Buller district [5], and of Mr. A. 

 McKay in "Westland [6] ; while E. H. Davis in 1870 described the 

 rocks of the Dun Mountain district [7]. In the last three years 

 Dr. J. M. Bell has greatly increased our knowledge of these rocks in 

 the Hokitika [8] and Collingwood [9] areas, and the monograph 

 of Prof. Sollas on the rocks of the Hauraki goldfields [10] contains 

 also descriptions of rock-specimens from the Hokitika district 

 (pp. 185 et seqq.). Further, short accounts have been published of 

 the deposits of copper [11] and chrome-ores [12] in the serpentines 

 at Nelson. 



Of other than official geologists, G. H. F. Ulrich described the 

 peridotites of the Olivine and Bedhill ranges, and the associated 

 nickel-iron alloy awaruite [13]. F. W. Hutton described some of 

 the Nelson and Western Otago rocks [14]. Lastly, Prof. P. 

 Marshall has given valuable accounts of the rocks from the Cow 

 Saddle [15] and Anita Bay [16], and of the gabbro of Dun Moun- 

 tain [17]. To Dr. F. Berwerth we owe the identification of the 

 bowenite of Anita Bay [18]. 



3 Numerals printed in square brackets refer to the Bibliography, § IV, 

 p. 378. 



