REVIEWS 83 



formities. The Mississippian is represented by the Windsor series and 

 the salt is interbedded with gypsum and shale in this series. The 

 Windsor series has been intensely folded and faulted and is now exposed 

 on the crest of an anticline where the main workings are located. The 

 salt bed is about 75 feet below the surface. A shaft has been sunk to the 

 salt horizon and the salt is removed by mining. One bed of rock salt 

 over 21 feet thick is already being worked. Sylvite (potassium chloride) 

 is present as fairly pure lenses in the halite and probably is a replacement 

 of halite. Chemical analyses of rock salt show from 2 . 5 per cent to 1 1 

 per cent sylvite, and this potassium salt will probably be an important 

 by-product from this deposit. Very little is known concerning the 

 lateral extent of these salt beds, but since they were formed by the 

 evaporation of sea water during the recession of the Mississippian seas 

 in Windsor time, they are likely quite extensive. 



The Windsor series is probably much more extensive than formerly 

 thought, because limestone in Kings County, New Brunswick, formerly 

 correlated with the Albert series, which is unconformable below the 

 Windsor series, was found to contain Windsor fossils. A ntmiber of salt 

 springs occur in the area where these fossils were collected and in other 

 localities in New Brunswick and suggest the presence of salt beds in the 

 Windsor series of this province, although up to the present no development 

 work has been done near any of the springs. 



. J. F. W. 



The Limestone and Phosphate Resources of New Zealand. Part I. 

 Limestone. By P. G. Morgan. Geological Survey Branch, 

 Department of Mines, New Zealand, 1919. 



This is primarily a discussion in detail of the limestone resources of 

 New Zealand, considered particularly in their relation to agriculture, and 

 as such is mainly of local interest. The principal features of general 

 interest are several excellent plates that illustrate remarkable fluted 

 and pinnacled forms developed through erosion by solution. 



As bearing upon the origin of oohtic and pisolitic structures in 

 limestone, relations at Kotuku near Greymouth are of interest. Here 

 several drill holes, sunk in search of oil, discharge in geyser-like fashion 

 salt water highly charged with CO2 and dissolved calcium carbonate. 

 The greater part of the CO2 at once escapes and, in consequence, abun- 

 dant carbonate of lime is deposited wherever the water touches any 

 solid object. As the water flows away it forms numerous Httle balls of 



carbonate of lime, in size and shape resembling marbles. 



E. S. B. 



