1871.] HAWKSHAW — PEAT-BEDS, HULL. 237 



of the strata above the places in which these minerals occur, which 

 would probably reveal the conditions under which they had been 

 formed. They were probably produced by the decomposition of sili- 

 cates in the overlying rocks during the percolation of water. This 

 applies also to the Charlton locality. 



Mr. Careutheks mentioned that allophane often fills the inflo- 

 rescence of the Cycads of the Yorkshire Oolite, entirely destroying 

 the vegetable structure, and that it also occurs in clay nodules from 

 the coal-measures. Mr. Carruthers suggested that the decomposi- 

 tion of vegetable matter in clays might aid in the production of the 

 mineral. 



4. Notes on the Peat and Undeelying Beds obseeved in tlie Con- 

 STETTCTioN of the Albert Dock, HtTLL. By J. C. Hawkshaw, 

 Esq., F.G.S. 



[Abridged.] 



The author described the Albert Dock as extending east and west 

 along the foreshore of the Humber at Hull, for a distance of 4000 

 feet. The total area excavated was about 30 acres. AU the exca- 

 vations were carried to a depth of at least 8 feet, and in some in- 

 stances of 27 feet, below the level of low water. 



Before the commencement of the excavations the Hessle Clay, 

 peat, and overlying silt were met with in succession on the fore- 

 shore, the level of the top of the peat-bed at the west end of the 

 area being about 3 feet above the level of low water, and its thick- 

 ness from 3 to 4 feet. Eastward the bed followed the undulations 

 of the clay without much variation in general level for half a mile, 

 when it began to dip, attaining a depth of 12 feet below low-water 

 level at the lock-entrance, and then rising again. From this depres- 

 sion of the peat-bed, and the appearance of the overlying silts, the 

 author thought it probable that this had been an old channel of the 

 river Hull, and that the upper part of the peat had been removed 

 by scour. In support of this view he quoted the statements of 

 antiquarian writers. 



The peat rested directly on the Hessle clay, into which roots pene- 

 trated to a distance of 5 or 6 feet, generally following the direction 

 of vertical joints, which gave the clay a tendency to split into 

 prisms. These joints did not occur in the Purple Clay; and the author 

 suggested that they may have been caused in the Hessle Clay by its 

 drying by exposure before becoming covered with vegetation. The 

 sides of the joints were grey ; and this colour pervaded all the clay 

 that was intermixed with the peat and extended for a distance of 

 from 1 to 2 feet into the overlying beds of sUt. This grey tint pro- 

 bably resulted from the decoloration of the iron, due to deoxidation 

 by the vegetable matter of the peat. 



At its highest level, at the west end of the dock, the peat consisted 

 almost entirely of vegetable matters, including large accumulations 

 of moss, leaves, and masses of brushwood, layers of oak-leaves with 

 acorns, hazel-nuts, and fir-cones, Numerous remains of Coleoptera, 



VOL. XXVn. PAET I. S 



