RHOETIC BEDS AT LINCOLN. 



F. M. BURTON, F.L.S., F.O.S., 

 (ill insbo fo tiah . 



That the Rhoetic beds would be encountered in the new boring- 

 for water at Lincohi, which is intended to reach the Bunter, was 

 a foreg-one conclusion. 



On the 7th Aug"ust I had the pleasure of examining", with 

 Mr. J. H. Teag-ue, the eng^ineer in charg-e, the cores which had 

 been brougfht up in executing- the work, and the following- is 

 a short summary of the Rhretic portion. 



Unfortunately only those cores are preserved which appeared 

 to show decided changfes in character, and the intervening- beds 

 can only be conjectured, so that a detailed description ctf the 

 beds is impossible. 



After passing- throug-h 640 ft. of the Lower Lias, including- 

 20 ft. of the plinioi'bis zone, with its characteristic fossil, at the 

 base (in itself a matter of considerable interest, as the members 

 of this zone are very little in evidence in this part of the count}-), 

 a smooth, pale-blue, laminated stone, without fossils, was met 

 with, in all probability of Rhoetic formation ; but whether it can 

 be classed as the hig;hest of the Rhoetic beds in this area, or 

 whether it forms a narrow band at the base of the Lower Lias, 

 the beds succeeding- it must have represented the sandstones 

 and shales of the L'pper Rhcetic strata, for, 14 ft. below it — at 

 a depth of 654 ft. — the next core, preserved, is a narrow block, 

 barely 2 in. thick, of the usual 'black shales' of the Rhoetic 

 beds, crowded with characteristic fossils, and freely speckled 

 throughout with large mica-scales. 



These black shales, wfth the other Rhoetic deposits below 

 them, carried the bore down 22 ft. further, to the depth of 

 676 ft., when, as the next preserved core showed, the gfrey beds, 

 which are now classed by some g-eologists as Rhoetic, appeared, 

 continuing- down, for 23 ft. further, to the red marls of the 

 Keuper, which were reached at a total depth of 699 ft. 



No trace of the bone beds, nor of the pyrites, so abundant 

 in the Lea cutting-, could be seen. 



It is much to be regretted that so little has been preserved 

 in sinking this shaft, but, from the evidence we have, we are 

 justified in putting the total thickness of the Rhcetic beds in the 

 neighbourhood of Lincoln (including- the grey beds) as about 

 59 ft. 



I9P_-; September i. 



