365 



which can be disputed; Van't Hoff's results, however, 

 as to soluble anhydrite have been disproven by W. A. 

 Davis* who showed that it is ordinary anhydrite that 

 forms, and not, as Van't Hofif claimed, an anhydrite with 

 entirely different physical properties. This puts the 

 results as to anhydrite into a rather doubtful light. It is 

 certain that anhydrite is not deposited in water at ordinary 

 temperatures and under such conditions as exist at the 

 present day, and it is not deposited at much greater 

 temperature. 



On the other hand, gypsum is easily dehydrated at low 

 temperatures. It is much more probable that the calcium 

 sulphate deposits were deposited in the form of gypsum, 

 and that the pressure caused by the enormous layers of 

 sediments which were subsequently piled on top of it 

 partly or wholly dehydrated it. The dehydration of the 

 gypsum is observable at the present day. 



ALBERT MINES. 



From the western head of the gypsum quarries, a 

 road leads to the valley of Frederick brook and to the 

 area of the Albert series at Albert Mines. Along this 

 road, on the brow of the slope to the valley of Frederick 

 brook, are exposures of grey limestone dipping eastward at 

 angles of 60° to nearly 90°; in places the strata are con- 

 torted. Presumably the strata are traversed by a fault. 

 Along the road farther south where it parallels the railway 

 traversing Frederick brook valley, is a low cliff of coarse 

 conglomerate dipping to the east at a low angle. A short 

 distance east, the conglomerate is overlain by the grey 

 limestone, above the limestone occurs red sandstones 

 overlain by the grey beds of the Millstone Grit. No 

 gypsum is known to be present and though it may have been 

 cut out by a fault, it is more probable that the gypsum was 

 removed by erosion prior to the deposition of the Millstone 

 Grit. 



The conglomerate exposed in the cliff at the roadside, 

 and in a small cutting along the railway and elsewhere in 

 the neighborhood, is very dark in colour due to the presence 

 of hydro-carbons with which the rock is impregnated. 

 The conglomerate is the ordinary red conglomerate which 



*Jour. Soc. Chem. Ind. Vol. XXVI, 1907, p. 727. 



