Yol. 68.] THE KEUPEE MARLS AROUND CHARNWOOD. 281 



14. The Ketiper Marls around Char:n^wood. By Thomas Owen 

 BoswoRTH, B.A., B.Sc, E.G.S. (Read December 21st, 1910.) 



[Plates XIX-XXVI.] 



Investigation on the Keuper Marls during the past seven years 

 has been the subject of various papers ^ by the author, read before 

 the Leicester Literary & Philosophical Society, the British Association 

 (1907), and finally before the Geological Society (1910). 



xis the complete work is being published in book form, only a 

 brief abstract is given in these pages. 



The area under consideration — about 300 square miles in extent — 

 is situate on the eastern edge of the central plain of England, and 

 the greater part of it is within from 150 to 350 feet of sea-level. 



Eising sharply in this plain are the hills of Charnwood, formed 

 of pre- Cambrian rocks, peeping up through the mantle of Keuper 

 Marls, by which they were doubtless once completely covered. 



The Marls are now found on the flanks of all these hills, and 

 are seen in the quarries at Bardon Hill resting on the old rocks at 

 810 feet above O.D. and in joint-cracks up to within 32 feet of the 

 summit ^ (912 feet above O.D.), which is the highest point in 

 Charnwood. As has been shown by Prof. W. W. Watts,^ denudation 

 of the soft Marl cover is gradually revealing the pre-Triassic land- 

 surface almost intact. 



In this paper are described some of the details of the old rock- 

 surface found beneath Keuper Marl in the quarries. 



Generally, the quarries have been opened in the tops of the 

 buried or almost buried hills ; and as usually the extension of a 

 quarry on each occasion is carried on in the direction where the 

 overburden is at the time least, the outline of a quarry tends to be 

 almost exactly a contour of the buried hill. Consequently, but a 

 dwarfed impression of the irregularity of the rock -surface is 

 presented in the sections, and the steepest slopes are away from 

 the observer at right angles to the quarry-faces. 



Nevertheless, considerable 'humps' and 'hollows' are visible 

 wherever the margin fails to coincide exactly with the contour. 

 (See PL XXI and PL XIX, fig. 1.) The 'hollows' are cross- 

 sections of buried guUies leading down the old hillsides. The 



1 T. O. Bosworth, Trans. Leicester Lit. & Phil. Soc. vol. xii, pt. i (1908) 

 pp. 28-34 ; Gaol. Mag. dec. 5, vol. iv (1907) pp. 460-61, and ibid. vol. v (1908) 

 pp. 853-57. 



2 W. Keay & M. Gimson, ' Eelation of the Keuper Marls to the Oharnian 

 Eocks at Bardon Hill ' Trans. Leicester Lit. & Phil. Soc. vol. xi, pt. i (1907) 

 pp. 52-54. 



3 ' Charnwood Forest : a Buried Triassic Landscape ' Geogr. Journ. vol. xxi 

 (1903) p. 623. 



