88 TUE BEV. (•'. K. HALL, F.S.A., 



III. — On a Piece of Timber recently encrusted with Carbonate of 

 Lime from a Coal-Pit near Gunnerton, North Ti/nedale, with 

 some Remarks on the Rate of Formation of similar Deposits in 

 Ossiferous Caves in Connection with the Antiquitij of Man. By 

 the Rev. G. Rome Hall, F.S.A. 



A FEW weeks since (December, 1876,) Mr. Armstrong, the lessee 

 of the small land- sale colliery at Gunnerton Hill Head, the pro- 

 perty of the Rev. C. Bii'd, Yicar of Chollcrtou, a member of our 

 Club, brought to my house a piece of Timber which had been 

 used as a cage-girder, or slider for tlie cage in the shaft of a pit 

 recently disused, another shaft closely adjoining ha^dng been 

 sunk by him last year which is being worked at the present 

 time. 



In removing the boards from the disused shaft he observed 

 that many of them had become, as he conceived, ''petrified," or 

 turned into stone. Thinking that I might take some interest in 

 the phenomenon, he kindly placed a board from the lower part 

 of the shaft, but some distance from the bottom, at my disposal, 

 carrying it himself on his shoulders, a very heavy and burden- 

 some present it must have proved, a distance of one mile and a 

 half. 



The district forms a portion of the Carboniferous system, the 

 Mountain Limestone, and is thus described by the late Mr. Geo. 

 Tate, F.G.S., in general terras.* " Xorthward of the Tyne the 

 ^lountain Limestone consists principally of sandstones and shales, 

 with beds of limestones and coal interstratified, and of ironstone 

 nodules and layers among the shales. Tlie general direction of 

 the strata is south-westward, with a rise towards the north-west ; 

 but in their range they arc interrui)ted by many faults, whicli 

 however have the effect of extending the same beds from the 



Tweed to the Tyne A line from the mouth of the Aln 



to tlie Tyne, a little east of Corbridge, nearly marks their eastern, 

 boundary." Tlie site of both the present and the older pit, whence 

 the timber with encrustation of calcaieous spar has been taken, 

 is on the northern slope of the little valley of the Gunnerton Bum, 



* "Nww Flora of Norlliumberlaiid and Durhaui." Nal. Hist Trani., VoL II., p. 7, 



