150 The Rev. Maxwell H. Close, 



It is very remarkable that the above-mentioned conglomerates 

 near Rush and near Baldungan contain pebbles of Carboni- 

 ferous limestone. In other places the limestone is thickly 

 interspersed with small, angular fragments of older beds of 

 the same formation ; these are very visible when they are of a 

 different shade of colour from the matrix. These facts seem to 

 imply that there were minor, pretty even, upheavals and sub- 

 sidences during the deposition of the Carboniferous Limestone, 

 and that older beds were uplifted from the sea, and had acquired 

 considerable hardness when later beds were being formed partly 

 from their angular and rolled debris. The phenomenon of lenticu- 

 lar bedding", often to be observed in the Limestone, indicates that 

 there were irregular changes of condition connected with the 

 deposition of the strata. 



Upper Shales. — A remnant strip of this formation extends 

 from Baldungan towards the Naul, as indicated near the northern 

 extremity of the map. Its length is nearly ten miles, its mean 

 width about one and a half. The rocks consist of hard, splintery 

 shales, interstratified, in some places, with thin grits and flag- 

 stones. They used to be called Coal Measures, that term being 

 applied, in a wide sense, to include, not only the Coal Measures 

 proper, but all the strata between them and the top of the Car- 

 boniferous Limestone. They are to be correlated with the 

 Yoredale beds. Only the lower part of the group remains, the 

 thickness being about 500 feet. The overlap above mentioned, 

 still continues into this formation, as can be seen near the Bog 

 of the Ring, where these Upper Shades evidently extend beyond 

 the Limestone, so as to come directly upon the Lower Silurian. 

 Though this formation is properly described as conformable with 

 the Limestone, yet, occasionally, local unconformabilities have 

 been noticed between the contiguous beds of the two series. This 

 is what might have been expected, as the great general subsi 

 dence during the Carboniferous age must have been, not only 

 interrupted, but temporarily reversed at the end of the Limestone 

 period. As already mentioned, a similar temporary reversal 

 seems to have taken place during the deposition of the Limestone 

 itself; this being apparently necessary to explain the presence of 

 fragments of earlier beds in the later beds of that formation. 



The Upper Shales in this district contain a very characteristic 

 assemblage of fossils. There is a very interesting coast section 



