54 



NUMMULITIC SERIES. 



Formation inconstant in the Punjab. — The nummulitic rocks of 

 this district belonging to one of the groups of the Upper Punjab most 

 liable to local changes — changes which are, nevertheless, insufficient to 

 affect the recognition of the formation in different parts of the country, 

 the formation may be said to present itself under three more or less 

 separate aspects, namely, those of the Salt Range type, the Subathu 

 type, and the hill nummulitic type. 



Here the two former of these types seem to be united so that the 

 local groups may be looked upon as exhibiting an unusually extensive 

 development of the Subathu character blended with some of the features 

 characteristic of the Salt Range nummulitic zone. 



Local inconstancy. — As the general features of the nummulitic rocks 

 of the country are versatile, so, even within the limits of this salt- 

 bearing region, the sections across it vary in different places, from the 

 entire absence of this group by thinning out, to its enhanced thickness 

 by including beds not usually present. Where thinning out of the 

 limestones takes place, the upper portions are always the first to disap- 

 pear ; and the chief additions to the whole group are a mass of shales 

 and sometimes of light coloured sandstones, which locally come in below 

 the main limestone zone. 



General succession. — The inversions of the adjacent strata are most 

 prominently marked by the occurrence of these limestone beds, which, as 

 it were, form a key to the complicated stratigraphy of the hills, being 

 most extensively distributed, while the clays or soft shales and sand- 

 stones are collected into a group by themselves at the base of the series, 

 rather than distributed by alternation through it, though occasional bands 

 of shale do occur also in the latter way. The following may be given 

 as a diagramatic table of all that is certain to belong to the nummulitic 

 limestone group in this district, there being, however, reason to suppose 

 that this eocene series may include all the rocks below the limestone 



( 158 ) 



