THE GEOLOGICAL STRUCTURE OF THE CANONBIE COALFIELD. 837 



Before the survey of that district was completed Mr Jack, who had mapped the greater 

 portion of the area, left for Queensland, and the completion of the work was shared by 

 Mr B. N. Peach. In the course of the survey great difficulty was experienced in 

 correlating the subdivisions of the Carboniferous system as there developed with those 

 of the Midland valley of Scotland, due partly to the variation in some of the groups 

 from the normal Scottish types, and partly to the fact that the mapping of the Carbon- 

 iferous rocks of the north of England had not been completed to the Scottish border. 

 Eventually, the view was adopted and expressed in the Geological Survey map of the 

 district (sheet 11 — one inch) that the Canonbie coalfield belonged to the Calciferous 

 Sandstone series, which represented part of the Carboniferous Limestone series of 

 England. 



The pakeontological evidence, however, did not harmonise with this conclusion. 

 After the mapping was completed Mr Macconochie began the fossil-collecting in that 

 district, and obtained a series of plants from the Canonbie coalfield and from Carbon- 

 iferous strata occupying a lower geological horizon. These plants were named and 

 described by Mr Kidston, the results of his researches being published in the 

 Transactions of this Society.* In his paper a list of the plants from that coalfield 

 was given, but no geological horizon was assigned to them, out of deference to the view 

 then held by the Geological Survey. On the evidence of the plants alone, he was led 

 to the same conclusion as that of Mr Gibsone and Mr Binnev. that the coal-bearing 

 strata of Byre Burn and Rowanburn belong to the Coal-measures. In the course of his 

 work Mr Macconochie incidentally found plants in certain red shales at Jockie's Sike, 

 near Biddings Junction, which suggested to Mr Kidston that these red shales and sand- 

 stones near the border might be the representatives of the Upper Coal-measures of 

 England. This striking confirmation of Mr Binney's sagacious conclusion regarding 

 the age of these sandstones was first announced by Mr Kidston in his presidential 

 address to the Royal Physical Society, Edinburgh, in 1893. 



It may be further noted that Mr Macconochie, while collecting the fossils from 

 the massive limestones of Peterscrook, Harelaw Hill, and Gilnockie, was struck with the 

 resemblance of the facies of organic remains to that found in the lower limestones 

 of the Edge Coal series of the Midland valley of Scotland. This opinion was 

 shared by the late Mr Bennie, who compared the microzoa from the shales of the 

 Gilnockie limestone with those obtained from the horizon of the Hurlet limestone of 

 Fife. 



The subsequent completion of the mapping of the Carboniferous rocks in 

 Northumberland, northwards to Berwick and the Cheviots, threw much light on the 

 sequence and peculiar lithological features of the members of that system in Liddisdale 

 and Eskdale. 



The revision of the Scottish coalfields, now in progress, furnished an opportunity 



* " Report on Fossil Plants collected by the Geological Survey of Scotland in Eskdale and Liddisdale," Trans. 

 Roy. Soc. Edin., vol. xxx. p. 531. 



