THE 



JOURNAL OF GEOLOGY 



APRIL- MAY, 1894. 



THE OIL SHALES OF THE SCOTTISH 

 CARBONIFEROUS SYSTEM. 



The Lower Carboniferous Rocks of the east of Scotland have 

 within the last quarter of a century attained great economic and 

 geological interest from the oil-bearing shales they have been 

 found to contain. The district around Edinburgh is one of 

 great complication, and until the operations of the shale mines 

 began large parts of the ground which is usually deeply covered 

 with glacial drift were geologically but imperfectly explored. It 

 is only recently that the chief oil shale districts have been 

 mapped correctly, and the new edition of the geological map of 

 the Edinburgh district, on which I have been engaged for sev- 

 eral years tracing out the oil shale outcrops, etc., has only been 

 published within the last six months. A detailed account of 

 the structure of this area has not yet been published, and 

 beyond a few short papers by myself and others in various sci- 

 entific journals, nothing of importance has been written on this 

 interesting subject. 



The Carboniferous system of Scotland is broadly divisible 

 into the following groups : 



4. Coal Measures, with the most iinporta?it coals. 



J. Millstone grit, chiefly barren sandstones. 



2. Carboniferous Lijnestone Series, with beds of limestone above' 

 and belozv, and shales, sandstones, etc., interbedded with seams 

 of excellent coal in the center. 



I . Calciferous Sajidstone Series, with sandstones, estuarine lime- 

 stones, jfiarls, seams of oil shale and occasional impure coal, the 



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