of Derbyshire and Notts Coalfield. 293 



fine-grained light-grey matrix of marl. A fourth bed of siderite, 

 18 inches thick, forms part of the fireclay floor of the Alton Coal, 

 immediately overlying a bed of hard grey Ganister. I have found 

 similar siderites at various horizons in the Nottinghamshire Coalfield : 

 they closely resemble the Staffordshire example recently described by 

 Dr. Teall (5). 



The Ruddington Boring. (Fig. 1, Section V, and Fig. 2, Section V.) — 

 Several references to this important boring have been made (6), and 

 the section has recently been published by the Geological Survey (7). 

 After penetrating 670 feet of Trias the boring proved 440 feet of 

 Lower Coal-measures and 760 feet of Millstone Grit. The following 

 fossils were obtained from an unknown depth by the late James 

 Shipman, F.G.S. (8):— 



Carbonicola acutn. Anthracomya modiolaris. 



C. acuta, var. r/iomboidalis. Acanthodes TFardi. 



G. aquilina. 



Owing to their wide range these fossils yield no assistance in 

 identifying the horizon reached in this boring. 



From a study of a nearly complete series of cores I am able to add 

 the following important details concerning this boring. The published 

 account places the surface of the Coal-measures at a depth of 687 feet ; 

 but it must occur a few feet higher, because I obtained pith -casts of 

 Cahmites sp. at 682 feet. The upper 20 feet of Coal-measures 

 consist of red and grey micaceous sandstone with thin beds of blue 

 marl. As these red measures pass downwards into typical grey 

 sandstones and sandy shales of the Wingfield Flagstones, they must 

 be regarded as Wingfield Flagstones stained by percolation from the 

 overlying Bunter. These beds contain numerous badly preserved 

 plant-remains, including — 



Cahtmites sp., cf. varians, Sternb. 

 Cordaites sp. 

 Cro>isotheca sp. 



At 689 feet and at 698 feet are two thin bands of breccia composed 

 of angular fragments of marl and htematite set in a red sandy matrix. 

 This suggests that erosion has taken place. 



The Coal-measures were entered below the Kilburn Coal. Con- 

 clusive evidence of the horizon reached in this boring is furnished by 

 the coal 3 ft. 4 in. thick at a depth of 1072 ft. 9 in. The dark 

 pyritous roof-shale in contact with the coal is crowded with flattened 

 marine fossils, including — 



Pterinopecten papyracens. 

 Goniatites sp. 

 Schizodus sp. 



The floor of the seam is a hard, grey, compact Ganister passing down- 

 wards into fireclay. This coal must, therefore, be the Alton Coal. 



It has been generally assumed that from Nottingham to Ruddington 

 the Coal-measui-es dip steeply to the north, but an examination of 

 the cores (which have a diameter of 7 inches) does not confirm this 

 opinion ; with the exception of a few feet of false-bedded sandstones 

 belonging to the Wingfield Flagstones, the Coal-measures appear to lie 

 in a horizontal position. After allowing for the faults proved in the 



