102 Mr. Tate on the Geology and ArchcBology of Beadnell. 



chiefly of cellular tissue, Sigillariae were extremely succulent ; 

 they grew in swamps and marshes, their long and numerous 

 Stigmaria roots and rootlets forming an entangled mass and 

 permeating the mud in all directions, in a manner similar to 

 that of the living water lily in shallow lakes and pools. The 

 roots sometimes exhibited a crucial arrangement, uniting 

 into four main portions, separated from each other by deep 

 channels and forming a dome from the summit of which, the 

 furrowed and scarred stems, clothed in the upper parts with 

 a long, narrow and pendent foliage, rose to the height of 

 nearly 100 feet."* 



Other conditions of the Carboniferous Era are made known 

 by several of the sandstones, which present ripple-marks, 

 oblique lamination, and fossil worms and worm tracks, in- 

 dicating ancient beaches and the action of waves and currents. 

 When deposits are made in water comparatively tranquil, the 

 planes of the several beds are pretty nearly parallel to each 

 other ; but some sandstones exhibiting in mass this ordinary 

 stratification have also included in them, thin layers or 

 stratula, which are inclined sometimes highly to the plane of 

 the principal bed ; this is oblique lamination, or as it is 

 frequently called, false-bedding^ of which there are many 

 examples in the Beadnell sandstones. Both ripple-marks 

 and false bedding result from the action of waves and 

 currents — the former being produced by the gentle motion of 

 waves, and the latter by stronger currents. After the reces- 

 sion of the tide furrows and ridges may be seen on sandy and 

 muddy coasts ; and these are similar in form and arrangement 

 to those left impressed by ancient waves on the Beadnell 

 sandstones ; where they are there beautifully distinct ; some 

 of them are large, measuring 6 inches from one ridge to the 

 other ; and they usually trend from east by south to west by 

 north. As the line in which a current moves is at right angles 

 to the direction of such marks, the ancient currents which 

 rolled over the Beadnell coast must have come either from 

 the north or the south. 



Mr. H. C. Sorby has attempted to determine the direction 

 whence currents came, by observations on the dip of the 

 stratula, as he considers the direction to be the opposite to 

 this dip in relation to the plane of true bedding ; and he con- 

 cludes from a series of observations, that the drifting current 

 which formed the coal sandstone beds on the southern part of 

 the coast of Northumberland came from north 9° east.t The 



* Tate's Fossil Flora of the Mountain Limestone Formation in Dr. Johnston's 

 Botany of the Eastern Borders, p. 299. 



t Proceedings of the Yorkshire Geological Society for 1852, p. 232. 



