ORIGINAL ARTICLES. 



Dolomitization in the Carboniferous Limestone of the 



Midlands.^ 



By L. M. Parsons, M.Sc, D.I.C, F.G.S. 

 (PLATE IV). 

 CONTENTS. 



T. Introduction. 

 II. Note on Classification and Evidences. 



III. The Dolomitic Limestones and Dolomites between Gratton Dale and 



Cromford. 



IV. The Dolomitic Limestones of Gratton and Long Dale. 

 V. The Dolomites between Parwich ]\Ioor and Wirksworth. 



VI. Summary ot" Conclusions and Comparison with the Leicestershire 

 Dolomites. 



I. Introduction. 

 rFHE contents of this paper record the results of a detailed 

 -*- examination of certain extensive areas of dolomitization in the 

 Carboniferous Limestone of the Midlands. During the period 1912 

 to 1914 the faunal succession in the Carboniferous Limestone 

 bordering the Leicestershire Coalfield chiefly claimed my attention,^ 

 but many problems associated with dolomitization arose in connexion 

 with that work and have been discussed in a previous paper. ^ Being 

 thus introduced to a study of metasomatism which yielded interesting 

 results in Leicestershire, I turned my attention to the larger 

 Carboniferous Limestone outcrop in Central Derbyshire, where a 

 considerable thickness of dolomitized beds awaited description. 

 The question as to whether the dolomitization in Derbyshire affected 

 material on similar horizons or exhibited other features analogous 

 to those of the dolomitization of the Leicestershire outcrops afforded 

 considerable scope for investigation. Additional incentive to this 

 particular study lay in the fact that dolomitization in the 

 Carboniferous Limestone of this country had not been treated as a 

 principal theme, but had been briefly described in notes occurring 

 in papers by various authors, whose main object was the elucidation 

 of other joroblems such as faunal succession.^ 



The widespread dolomitization which this paper attempts to 

 describe occurs in the Gratton, Winster, Matlock, and Brassington 

 districts of Derbyshire. At other localities in the same county 

 smaller local develojmients of dolomitic material, obviously of sub- 

 sequent origin, occur, but these are not comparable with the massive 

 apparently bedded material of the districts mentioned above, and no 

 description of them is given. 



^ Part II of Thesis approved for the Degree of Doctor of Science in the 

 University of London. 



- Described in Quart. Jouni. Geol. Soc, vol. Ixxiii, 1917, p. 84. 



3 " Dolomitization and the Leicestershire Dolomites " : Geol. Mag., 

 1918, pp. 246-58. 



* e.g. Sibly, Q.J.G.S., vol. 1908, p. 54. 



