1 80 Mr. Rose's Sketch of the Geology of West Norfolk. 



tune to see Mr. Smith at the meeting of the British Association 

 at Cambridge, he so positively assured me of the existence 

 of the gault that I no longer questioned such high authority, 

 and on my return home redoubled my inquiries : fortunately, 

 two wells were sunk soon after my return, near to one of the 

 localities marked on Smith's map, and from them I have as- 

 sured myself that the gault exists as placed in his map and 

 section. Mr. Smith has laid down but a few detached spots, 

 those only where he had seen it; had he extended those patches 

 into one continuous line, he would have correctly traced nearly 

 its whole course : such adherence to ocular demonstration 

 greatly enhances the authority of this veteran in geology. 



A nearly continuous valley, situated between the outcrops 

 of the chalk and lower greensand, extends from Wretton, 

 through West Dereham, Shouldham, Marham, Pentney, 

 Bilney, Gayton, Grimstone, to Congham, and along this valley 

 I have traced the gault the entire distance, with the exception 

 of one spot at Stradsett, where it is hidden by a large accu- 

 mulation of diluvium, which here destroys the continuity of 

 the valley. At West Newton this valley terminates, or, rather, 

 becomes a transverse valley, taking its course westward through 

 the sand hills; from this place to Hunstanton the chalk and 

 lower greensand occupy the same ridge : no valley intervenes, 

 an indication of the absence of a soft stratum between them, 

 as exhibited at Hunstanton Cliff, where the red chalk is inter- 

 posed between the two. Professor Sedgwick says, the red 

 beds of Hunstanton are " exactly in the place of the gault of 

 Cambridge, and contain some of the gault fossils, for ex- 

 ample, the Belemnites Listeria such is the fact, and I fully 

 concur with the distinguished Professor in considering the 

 red beds the equivalent of the gault. 



The two wells before mentioned sunk in the gault at Bilney 

 and Pentney, about a mile apart, and in the direct line of 

 its strike, afford the following section : 



Pentney. Ft. Inch. 



1. Vegetable soil and gravel 4 



2. Rubble chalk, succeeded by stiff blue clay,^ 



containing Belemnites minimus ; the"goltV 10 

 brick-earth" of Smith J 



3. Hard gray limestone, containing Terebratulce"} 



biplicatae resembling those in the red chalk > 6 



of Hunstanton J 



4. Blue clay or gault, very tenacious 2 



5. Black sand 1 



