Geology. - 497 



II. Geology. 



1. The Geology of the Queenstown Subdivision ; by James 

 Paek. New Zealand Geological Survey, Ball. No. 1 (new series). 

 Wellington, 1909. — This report of 112 pages, with geological 

 maps and numerous excellent photographs, published under 

 authority of Dr. J. M. Bell, Director of the Survey, treats one of 

 the most interesting districts of southern New Zealand, including 

 Lake Wakatipu, in the heart of the mountains between the plains 

 of the eastern slope and the fiords of the western coast. The 

 mountains, 6,000 to 8,000 feet in height, consist chiefly of Paleozoic 

 mica and other schists, compressed into closed overturned folds, 

 so as to give a general monoclinal dip of moderate or small angle 

 to the west. The chief longitudinal valleys are described as 

 established along over thrust shear-planes in the overturned 

 synclines, leaving the overturned anticlines to be less worn down 

 in the ridges ; but the text and maps do not present the facts in 

 sufficient detail to enable the reader to judge of the certainty of 

 these conclusions. Fossiliferous Miocene sandstones are included 

 in one of the closed synclines ; in one locality these beds may be 

 traced, in apparent conformity with the foliation of the schists, 

 from the bottom of a transverse valley at an altitude of 1,800 ft., 

 obliquely up the mountain side to an altitude of 5,300 ft. "Such 

 profound involvement of a thin band of Miocene strata in a 

 highly altered Paleozoic formation seems highly incredible, but the 

 stratigraphical evidence could not be clearer, even if the Tertiary 

 sandstone were a contemporary bed of coal interbedded in the 

 schist" (p. 63). Pleistocene glaciation is described as having been 

 "perhaps without a parallel outside the polar regions" (p. 25), the 

 polar regions of to-day being presumably referred to. All the 

 valley glaciers were united in a "great continental ice-sheet," the 

 surface of which "formed a vast plateau, through which only the 

 tops of the highest peaks appeared." The longest chapter in the 

 report is devoted to Economic Geology ; the gold-bearing lodes 

 being of most importance. 



The discussion of certain topics is not so discriminating as 

 might be wished. For example, it is stated that "the lower arm 

 of Lake Wakatipu is doubtless to some extent a rift valley, as 

 may be judged by the dislocation of the schists on the two sides 

 of the lake" (p. 20); yet no evidence is presented to show that the 

 present depression of this arm of the lake is directly dependent 

 on the faulting, as ought to be the case in a rift valley; moreover 

 the structural sections clearly suggest that great erosion has taken 

 place since faulting. If the faulting once produced a depressed 

 trough, later erosion seems to have so profoundly modified this 

 initial form as to require another name than 'rift-valley' for the 

 present form. Again, the discussion of glacial erosion is inconclu- 

 sive, partly because the author seems to take Ramsay's views on 

 fchis subject as adequate ; partly because the results reached are 



