2 ME. E. A. NEWELL AKBER ON THE [Feb. I903, 



concerned with the physical and stratigraphical geology of the 

 Cumberland Coalfield, in regard to the horizons from which plant- 

 remains have been obtained, and the evidence which these plants 

 present as to the age of the different beds. 



The succession of Upper Carboniferous rocks in the region in 

 question is apparently twofold: an essentially arenaceous 

 series, overlying argillaceous and carbonaceous deposits. 1 



The arenaceous series, of at present unknown vertical extent, 

 but which is at least 600 feet thick, consists of yellowish-grey, red, 

 or purple, massive sandstones, alternating with beds of shale and 

 fireclay of secondary importance. Thin bands of coa] and haematite 

 also often occur. This series is typically developed in the immediate 

 neighbourhood of Whitehaven, as well as in other parts of the 

 district, and is commonly known as the Whitehaven Sandstone. 

 The term ' Whitehaven Sandstone ' has, however, been applied, on 

 grounds which are not entirely satisfactory, to rocks of somewhat 

 similar lithological composition in other districts. I propose, there- 

 fore, to speak of this series, as developed in this area of the 

 Cumberland Coalfield, as the Sandstone Series. 



The carbonaceous deposits, lying below the Sandstone Series, 

 are at least 1300 feet thick, 2 but here again there is some doubt as 

 to the vertical extent of the series, since the base has not so far 

 been definitely determined. 3 It consists essentially of argillaceous 

 material, containing many seams of coal, often of considerable 

 thickness. These form the productive portion of the Cumberland 

 Coalfield, and are extensively worked in the district in question. 

 Some arenaceous deposits also occur in this series, especially in the 

 lower portions, where this type of rock seems to increase in im- 

 portance in several localities. The whole of these beds below 

 the Sandstone Series are locally known as the Coal-Measure s, or 

 Lower Coal -Measures, but I prefer to speak of them for the 

 present as the Productive Measures, in order to avoid any 

 imputation as to age or horizon ; questions which, so far, have not 

 been established on a satisfactory or definite basis. 



By almost every observer, from Sedgwick onward, the Sand- 

 stone Series has been stated to overlie the Productive Measures 

 unconformably, and this is maintained nowadays by those who 

 are engaged in working the Productive Measures in this district, 4 



1 J. D. Kendall (96) p. 205, etc. ; also id. (83) p. 321. The numerals in 

 parentheses after the authors' names indicate the year of publication of the 

 paper, to which reference will be found in the Bibliography on p. 21. 

 " 2 J. D. Kendall (83) pp. 347-48 & (96) p. 212. 



3 See p. 20. 



4 Special reference to the unconformity will be found in Sedgwick (32) 

 p. 344, Holmes (96) p. 406, & Kendall (96). So far as I am aware this has 

 only been disputed by Mr. Strahan, on the ground that there was no definite 

 base to the Sandstone Series ; see J. D. Kendall (95) Discussion, p. 236, and 

 id. (96) p. 205. Personally, I have had no opportunity of studying the 

 junction of the Sandstone Series and Productive Measures in the field, and 

 can therefore offer no observations on this point. 



