378 ME. A. M. PIXLATSOIJ ON THE NEPHEITE [Aug. I9O9, 



evidence of great pressure and shearing. Finally, the fibrous 

 amphiboles of secondary origin, as the uralitized pyroxenes of the 

 Cow Saddle, the altered olivine described above, and the amphibole 

 of contact origin at the Dun Mountain, have not been transformed 

 into true nephrite, apparently owing to the absence of the necessary 

 dynamic stress which is essential to its formation. 



In conclusion, the formation of the N/ew Zealand nephrite is 

 considered to have been accomplished by the formation of fibrous 

 amphibole by one or other of the methods discussed above — followed 

 by the action of great pressure and stress during rock-folding, on 

 the fibrous aggregates. The mechanical factor, as well as the 

 chemical one, has been essential to the production of the different 

 varieties of nephrite which occur. 



I wish here to express my warmest thanks to Mr. P. G. Morgan, 

 of the New Zealand Geological Survey, and Prof. P. Marshall, of 

 Otago University, Dunedin, for specimens of rocks given to me ; 

 and to Prof. W. W. Watts, of the Imperial College of Science 

 & Technology, for advice and suggestions in the preparation of this 

 paper. 



IV. BlBLIOGEAPHY. 



Peridotites. 



1. F. von Hochstettee. Zeitschr. Deutsch. GeoL Gesellsch. vol. xvi (1864) p. 341. 



2. Sir James Hectoe. Ota°;o Provincial Government Gazette, 1863, p. 460. 



3. J. Pabk. Reports Geol. Explorations (N.Z. Geol. Surv.) 1888-89, p. 233. 



4. J. Paek. Ibid. 1886-87, p. 121. 



5. S. H. Cox. Ibid. 1883-84, p. 1. 



6. A. McKay. Report Mines Uept. N.Z. 1893, C-3, p. 132. 



7. E. H. Davis. Reports Geol. Explorations (N.Z. Geol. Surv.) 1870-71, p. 103. 



8. J. M. Bell & C. Peasee. Bull. No. 1 (n. s.) N.Z. Geol. Surv. 1906. 



9. J. M. Bell. Bull. No. 3, ibid. 1907. 



10. W. J. Sollas & A. Maceat. ' Rocks of Cape Colville Peninsula ' (Wellington, 



1906) vol. ii, pp. 185 et seqq., 193. 



11. S. H. Cox. Reports Geol. Explorations (N.Z. Geol. Surv.) 1879-80, p. lj 



1881, p. 10 ; 1883-84, p. 84. 



12. S. H. Cox. Ibid. 1881, p. 3. 



13. G. H. P. Uleich. Quart. Journ. Geol. Soc. vol. xlvi (1890) p. 619. 



14. P. W. Hutton. Journ. & Proc. Roy. Soc. N.S.W. vol. xxiii (1889) p. 112. 



15. P. Maeshall. Trans. N.Z. Inst. vol. xxxviii (1905) p. 560. 



16. P. Maeshall. Ibid. vol. xxxvii (1904) p. 481. 



17. P. Maeshall. Ibid. vol. xl (1907) p. 320. 



18. P. Bebwebth. Sitzungsb. K. Akad. Wissensch. Wien, vol. lxxx (1879) p. 116. 



19. A. McKay. Reports Geol. Explorations (N.Z. Geol. Surv.) 1878-79, p. 97. 



20. J. Pabk. Trans. N.Z. Inst. vol. xxxvi (1903) p. 431. 



21. T. G. Bonnet. Quart. Journ. Geol. Soc. vol. lxiv (1908) p. 160. 



22. C. R. Van Hise. ' Treatise on Metamorphism ' Monogr. 47, U.S. Geol. Surv. 



1904, p. 280. 



23. J. Paek. Bull. No. 5 (n. s.) N.Z. Geol. Surv. 1908, p. 28. 



24. A. M. Pinlatson. Trans. N.Z. Inst. vol. xl (1907) p. 76. 



25. W. Sket. N.Z. Mines Handbook (Wellington, 1906), p. 517. 



26. Amer. Journ. Sci. vol. v (1822) p. 346 (G. T. Bowes), & vol. xv, ser. 2 (1853) 



p. 212 (J. L. Smith & G. J. Beush). 



27. C. A. McMahon. Min. Mag. vol. ix (1890) p. 187. 



28. P. Maeshall. Trans. N.Z. Inst. vol. xl (1907) p. 81. 



