24 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 22, 



on, about a furlong and a half beyond a crossing over the rail- 

 way, there is a small sand-pit. Its position may be found on the 

 Ordnance Map on the side of the hill opposite the last hin" Ald- 

 ringham ChurcA." Here we met with an abundance of impressions 

 of shells in the more clayey layers. The most common species was 

 Mytilus edulis. The shells (as well as I can distinguish them) appear 

 to be — 



Mytilus edulis (abundant). Pecten. Cardium. 



Two furlongs further to the north is an old pit overgrown with 

 herbage. It is in brown sand. Near it is another of similar ma- 

 terial with water in it ; and a few yards further to the north the 

 Thorpe " shell-pit " is reached. This has been considered, I beheve 

 rightly, to be an exposure of the Eluvio-marine or Norwich Crag *. 

 Its thickness is very considerable, but owing to the state of the pit 

 it is not possible to estimate it exactly f. It must, however, attain 

 ten or twelve feet in the pit. There is also a trace of the same bed 

 in the bank on the western side at the end of the lane near the n 

 in " Aldringham Common." This must be 30 feet or more above 

 the bottom of the pit, though it does not necessarily foUow that the 

 deposit was that thickness ; nor am I positive that it is in situ. 



At the bottom of the " sheU-pit " is a small pool of water, and 

 digging at its edge I soon reached the bottom of the bed of Crag. 

 In its lowest layer were numerous pebbles of indurated brown 

 micaceous sandy clay, and beneath it the brown sandy clay itself, 

 from which they had evidently been derived. 



A strong spring rose from the junction as I dug, and I have no 

 doubt it is the same spring which supplies the small pond resting on 

 brown sandy loam, already mentioned as being close at hand. 



We were impressed with the opinion that we here had theFluvio- 

 marine, or Norwich Crag, resting upon the Chillesford Clay. Before 

 my second visit to the place it occurred to me that this Crag might 

 be a drifted condition of the Mya-bed, as I believe the fifteen feet of 

 shelly Crag resting on Coralline Crag near Ferry-farm to be. But on 

 examining the evidence again I was confirmed in my former opinion. 



I have mentioned brown sands as covering the Chillesford Clay at 

 both the Aldborough brick-pits, and as appearing again between the 

 marsh (through which flows the Hundred River) and the shell-pit. 

 These sands are, as I have stated, fossiliferous in the latter place. 

 They may be seen, emerging from beneath the Boulder- clay, at 

 Aldringham Green, and they are again capped by it just north of the 



* Woodward, Phil. Mag. 1835, p. 354. Gunn's Geology of Norfolk, p. 12. 

 Wood on Eed Crag. Ann. & Mag. Nat. Hist. March 1864, p. 9. 

 t The species I found here were — 



Buccinum undatum (abundant). Tellina obliqua. 



Purpura lapillus. lata ? 



Litorina litorea (abundant). prsetenuis. 



Conovulus pyramidalis. Mactra solida. 



Cerithium tricinctum. Cardium edule. 



Turritella communis. Cyprina Islandica. 



Pecten opercularis. Mya arenaria ? 



Mytilus edulis. 



