108 Transactions. 



The largest block in the breccia occurs in place, at the foot of the 

 sea-cliff in the first sandy cove south of Rocky Point. It is an included 

 breccia-boulder, partially rounded at the corners and sides, compact,- and 

 intensely hard. It measures some 7-5 ft. by 5-3 ft. by 4-5 ft. Its upper 

 surface is fairly flat, and covered with distinct striae that, as a rule, run 

 parallel with the longer axis of the block. The area of the striated surface 

 is about 10 square feet. Several of the smaller included blocks on the 

 south side of the cove are similarly striated. 



This remarkable rock resembles the typical Te Anau breccia of Sir 

 James Hector. It is underlain, apparently conformably, by the semi- 

 metamorphic Kakanuian rocks of Hector, which everywhere in Otago 

 overlie the mica-schists of Central Otago. There is no internal evidence 

 to fix the age of the Kakanuian rocks. All that can be said is that they 

 underlie the Mount St. Mary series, which is Triassic, and overlie the 

 mica-schists of the interior. The Te Anau series of Hector, as identified 

 by him in Nelson, conformably underlies the Maitai series, which is now 

 known to be Upper Carboniferous or Permo-Carboniferous. I have always 

 found it difficult to separate the Te Anau rocks from the Maitaian, and in 

 1910 grouped them as belonging to the same formation. Hector ascribed 

 the Te Anau series to the Devonian period, the only evidence in favour 

 of this being its inferior and conformable relationship to the Maitaian, 

 which he placed in the Carboniferous. 



In Nelson and Marlborough, the rocks identified by Hector and McKay 

 as belonging to the Te Anau series are underlain by semi-metamorphic 

 rocks of supposed Kakanuian age. 



The Taieri Mouth breccia and overlying greywackes may very well 

 belong to the Te Anau series of Hector, and the underlying grey silky 

 micaceous phyllites to the Kakanuian. If this position can be established, 

 the Taieri Mouth breccia may be placed in the Upper Carboniferous or 

 Permo-Carboniferous. ' 



This is the first discovery of striated boulders in the Palaeozoic 

 formations of New Zealand, and the origin of the striae is certain to give 

 rise to some diversity of opinion. 



The stria tion may be glacial or dynamical. If the striated boulders 

 occurred along the fracture of a shear-plane I should ascribe the striation 

 to shearing. Though crushed and broken, the breccia shows no evidence 

 of shearing along defined planes, and for this reason I am inclined to 

 favour the glacial hypothesis. 



If the glacial view be sustained we are at once confronted with the 

 questions — (a.) What relationship, if any, does the Taieri Mouth breccia 

 bear to the glacial deposits reported in the Upper Palaeozoic formations 

 of India,* Australia, f South Africa, J and Brazil§ ? (6.) Was the glaciation 

 al^pine or secular ? (c.) Did the ancient Gondwana continent extend south- 

 ward to the New Zealand area ? 



* H. B. Medlicott and W. T. Blanford, Manual of the Geology of India, pt. i, 

 p. 110, 1879; and R. D. Oldham, Quart. Jour. Geol. Soc, p. 469, 1894. 



t T. W. Edgeworth David, Geology of the Hunter River Coal-measures, Mem. 

 Geol. Stirv. N.S.W. No. 4, p. 124, 1907. 



J E. T. Mellor, Study of the Glacial Conglomerate in the Transvaal, Quart. Jour. 

 Geol. Soc, vol. 61, p. 682, 1905; W. M. Davis, Bull. Geo. Soc. Am., vol. 17, p. 413, 

 1906 ; and others. 



§ David White, Permo-Carboniferous CUmatic Changes in South America, Am. 

 Jour. Geol, vol. 15, p. 618, 1907. 



