478 Revietvs — Geology of New Zealand. 



pressure, as is the case with the lower ' artesian- water sandstone ' 

 at the present day. 



In the articles to which reference has been made, the author dealt 

 with the probable sources of the artesian waters, their saline 

 ingredients, the amount of discharge, etc. In the present work he 

 has amplified the information on the wells and borings, and has 

 given the results of experiments to show the mutual interference of 

 one well or boring on another. The data show that the shutting 

 down of a flowing well or the opening of a closed one may produce 

 a marked effect within an hour, when the distance is more than 

 500 metres. 



The author discusses the drifting of the sands, and the various 

 economic aspects of the Kharga Oasis, adding a few notes on sport 

 and natural history. To geologists, and especially to those interested 

 in the problems of water-supply, the work contains a great deal of 

 important practical as well as scientific information ; while to the 

 general reader the story of the wonderful work achieved in ancient 

 times by means of artesian wells and irrigation in the desert regions 

 of Upper Egypt will be found both fascinating and impressive. 



II. — Geological Suevet of N'ew Zealand. 



" rpHE Geology of the Mikonui Subdivision in North Westland," by 



JL Mr. P. G. Morgan, forms the subject of Bulletin No. 6 (New 

 Series), 1908. The country here described borders the Wanganui 

 Eiver and the Tasman Sea to near Hokitika, on the coast of the 

 Southern Island, north - west of Christchurch. The oldest rocks, 

 comprising schists and grauwackes, form an intensely folded and 

 altered complex of sedimentary and igneous rocks, including serpentine. 

 They are grouped as the Arahura Series, and regarded as probably 

 Palaeozoic. A newer set of rocks, somewhat less altered and perhaps 

 of Carboniferous age, is known as the Greenland Series, and into this 

 bosses of granite have been intruded. A great gap succeeds, for the 

 next group is Eocene-Oligocene, and includes the local coal-bearing 

 strata, followed by some Miocene deposits. Then come the Glacial 

 ■drifts of Pliocene and Pleistocene age, and the Recent fluviatile and 

 marine deposits. The various sedimentary formations and the igueous 

 rocks are described in detail. 



The physiography of the area, the mountains and snowfields, the 

 rivers, lakes, gorges, hanging-valleys, plains, and other features are 

 also described and illustrated. 



The mineral resources appear to be limited; alluvial gold has been 

 obtained in the Totara and Eoss districts, and from black sands on the 

 sea-beach, and some auriferous quartz -mining has been carried on. 

 Eor the most part, however, the metalliferous deposits have not proved 

 to be extensive, the gold placers have largely been worked out, and 

 the coal-mining has not been satisfactory. It is remarked, however, 

 that in respect to water-power Westland is richly gifted. 



The work is illustrated by many excellent pictorial views, as well as 

 by neat colour-printed topographical and geological maps and sections. 



