PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY OF LONDON 



1827—1828. No. 7. 



March 7. — A Paper was read " On the Geological Relations and 

 Internal Structure of the Magnesian Limestone, and the lower por- 

 tions of the New Red Sandstone series, in their range through Not- 

 tinghamshire, Derbyshire, Yorkshire, and Durham." — By the Rev. A. 

 Sedgwick, M.A. V.P.G.S. F.R.S. &c. 



A sketch of the subjects contained in this paper was laid before 

 the Society in 1826 (Nov. 17) : — They were resumed in a more sy- 

 stematic and detailed form during two meetings in 1827 ; and are 

 now terminated by the observations read at the present meeting, 



The contents of the Memoir are presented in the following order : 



Part I. — § 1. Introduction. — The new red sandstone is considered 

 as one great complex formation, interposed between the coal mea- 

 sures and the lias j — with two calcareous formations subordinate to it, 

 one in the lower part of the series (the magnesian limestone), and 

 another in the upper part (the muschel-kalkstein) . The lower of the 

 two calcareous formations is considered in detail ; the upper has not 

 yet been discovered among the British secondary deposits. 



§ 2. External characters of the country through which the Magne- 

 sian Limestone ranges. — The form of the western escarpment is de- 

 scribed, and is supposed to exhibit proofs of great denudations ; and 

 the general character of the soils resting upon the formation is no- 

 ticed. 



§ 3. General distribution of the formation. — The range of the es- 

 carpment is given in great detail ; some errors of the geological maps 

 are corrected ; and in describing the eastern boundary, the enormous 

 masses of diluvium in the county of Durham are briefly noticed. 



§ 4. Outliers. — Sixteen outliers from the western escarpment are 

 described ; the most southern of which is at Conisborough. In addi- 

 tion to these, there are eight detached patches of magnesian lime- 

 stone on the line of bearing, which are not considered as outliers. 

 The most remarkable of these are seen in the range through York- 

 shire. 



§ 5. Relations of the Magnesian Limestone to a succession of Coal 

 Measures, — In a general point of view these formations must be un- 

 conformable, because the overlying beds are extended far beyond the 

 limits of the productive parts of the carboniferous order : and the fact 

 is also proved by actual sections in several parts of Yorkshire and 

 Durham. At the same time there are continuous tracts of country 

 where the want of conformity does not appear, and where the over- 



