14 ROYAL SOCIETY OF CANADA 



were accunmlated, were occasionally interrupted by more sudden 

 changes, involving disruption of the beds and more rapid sedimentation. 



At Martin's Head, upon the coast of St. John county, tliirty miles 

 southwest of Hillsborough, gypsum beds of limited extent and less pure 

 than those of the latter locality, but still merchantable, occur, and are 

 remarkable as forming the basal rocks of a synclinal basin, enclosed 

 between parallel bands of old Pre-Cambrian schists, and overlaid 

 directly by brown shales, gray calcareous sandstones holding nodules 

 of gypsum, and yellowish gray very ochreous sandstones, all dipping 

 at an angle of 45°. The marly beds have veins of fibrous gypsum, 

 and in places completely enclose, within greatly contorted laminœ, irre- 

 gular masses of gypsum from two to four feet thick. 



From the distribution of the gypsiferous strata around the Bay of 

 Fundy trough, at Martin's Head, Eiverside, Demoiselle Creek, Hills- 

 borough, Cape Demoiselle, Windsor, etc., it would follow that the con- 

 ditions originating such deposits, as discussed above, must have been 

 very general in this district near the close of the Lower Carboniferous 

 era. It is also quite possible that these conditions were not quite 

 the same at all points and that among the beds described several of 

 the modes of deposition or origination discussed above may find illus- 

 tration. 



