Axdkew. — On the Clarendon Phosphate-deposits. 451 



is in many places quite abundant as minute inclusions in the 

 quartz, mostly as stout prisms, hut also as long narrow crystals. 

 Many of the quartz crystals show by their undulose extinction 

 that the rock has been subjected to great strain ; the folia 

 occasionally are contorted and puckered, but this character is 

 not frequently observed. 



Occurrence. — For a rock of such a great age the schist lies 

 very flat, the average clip being about 10° in a westerly direction 

 (W. 10, N. 10). The difference in the dips between the schists 

 and the overlving limestone affords the only evidence of the 

 unconformity that exists between these formations. Near Kiln 

 Point the schist is traversed bv two sets of approximately vertical 

 joints which strike N. 13° W. and S. 13° E., and W. 22° N. and 

 E. 22° S. respectively. The schist contains no trace of organic 

 remains. The hills on the east of the gorge are composed en- 

 tirely of schist ; on the western side it is found outcropping 

 from beneath the limestone in a few localities, as at the base 

 of Cemetery Hill, between Cemetery Hill and Kiln Point, and 

 near Sutherland's quarry. The schist forms the basement rock 

 of the district, and to the north-west of the Trig. Hill it passes 

 out from beneath the overlying formations and extends west- 

 ward throughout the greater part of Otago. 



Age. — Within the district we get no information as to the 

 age, except that it is older than the limestone ; it forms part, 

 however, of the foliated schists of Otago, which Sir James Hector* 

 in 1875 considered as a Kakanui formation of Upper Silurian 

 age. In 1872 Captain F. W. Huttonf considered them as a 

 Tuamarina formation, but in 18751 he considered them identical 

 with the Upper Silurian Kakanui formation of Hector. In 



1885 Captain Hutton§ classed the Kakanui formation as the 

 lower part of the Takaka system, and thus of Silurian age. In 



1886 Hectorj I considered that they were the result of the meta- 

 morphism of Silurian and even younger rocks. In 1891 Hutton,*[ 

 as the result of a more complete investigation, revised his former 

 opinion and stated that they were of Archaean age. In 1886 

 Hutton repeated his former assertion, that they were Archaean. 

 Professor Park refers the schists to the Silurian. Thus the geo- 

 logical age of the schist is dubious, the authorities on the subject 

 being unable to agree as to whether it belongs to the Archaean 

 or to the Silurian. 



* Hector, Quart. Journ. Geol. Soc. (1865), vol. xxi. p. 128. 



f Hutton, Rep. Geol. Explor. N.Z. (1872-73), p. 31. 



% Hutton, "Geology of Otago" (1875), p. 32. 



§ Hutton, Quart. Journ. Geol. Soc. (1885), vol. xli, pp. 194, 198. 



j| Hector, " Outline of New Zealand Geologv " (1886), p. 83. 



1j Hutton, Trans. N.Z. Inst. (1891), vol. xxiv, p. 358. 



