The Upper Khirthar beds of North-West India

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Abstract
I. Introduction The type locality for the Upper Khirthar beds of India is the “Spin tangi” (or “white gorge”), a ravine traversing a prominent ridge in north-eastern Baluchistan; so it may be as well to recall the main facts regarding the Eocene sequence there, which was said by R. D. Oldham (1890b, pp. 94–6; 1892, pp. 21–4) to consist, in ascending order, of Dunghan Limestone, Ghazij Shales and the Spintangi Group. This designation does not seem to be applicable to an Eocene formation. It first appears on a map (Oldham 1890a, facing p. 58), where an area largely composed of Cretaceous outcrops is coloured as “Dunghan Limestone”. Similarly, when first described in the text (1890b, p. 94), this limestone is said to form “the greater portion, if not the whole” of Dunghan Hill, and to be from 1500 to 1800 feet in thickness. Dunghan Hill appears to be entirely composed of Mesozoic rocks; and the “Dunghan Limestone” probably represents the whole Cretaceous sequence following the Neocomian belemnite bed, and may range from the Turonian to the Maestrichtian inclusive. The Geological Survey of India seems to have accepted Dunghan Hill as the type area for this formation ( vide Holland and Tipper 1913–6, p. 46), and referred it to the Cretaceous. Oldham himself stated that the Dunghan Limestone contains “characteristically cretaceous forms” such as “ Crioceras, Baculites and Ammonites ” (1893, p. 291); while the supposed “nummulites” in it, to which Oldham ( loc. cit. ) and Griesbach (1893, p. 115) referred, were afterwards said by

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