58 WYNNE : TRANS-INDUS SALT REGION, KOHAT DISTRCIT. 



layers having few fossils. These are again overlaid by lumpy, marly, 

 light-coloured bands full of Nnmmulites, Bivalves, a few Gastropods, some 

 Echinoids, and a general assemblage of ill-preserved nummulitic fossils, 

 the whole being succeeded by hard pale-gray or variegated compact 

 Alveolina marble, often of a dull, yellowish colour, and generally forming 

 the highest portion of the nummulitic limestone group. Perhaps the 

 most constantly present beds of the formation are the hard Alveolina 

 bands, but there are others of the more lumpy and earthy-looking light- 

 coloured limestone, apparently lower in the series, also very generally 

 present ; they contain a characteristic Gryphea- shaped fossil. The Num- 

 mulites are of various common kinds, generally present in the Upper 

 Punjab eocene ; many of these are already described ; but no thorough 

 examination of the nummulitic fossils has as yet been made. The size 

 of the Nnmmulites varies from extreme minuteness to nearly an inch in 

 diameter. The Alveolina also vary in size from that of a grain of rice to 

 three or four times the same proportions. 



Characteristics. — The lumpy fossiliferous bands, the generally light 

 colour of the rocks, their containing large sized Bivalves in some places 

 and less commonly large Gastropoda, the occasional occurrence of some 

 carbonaceous layers near the base, as well as the variable character of the 

 whole group, are all points which tend to link the nummulitic group of 

 this region with that of the Salt Range. 



On the other hand, the presence of the greenish weathering clays or 

 shales, the fine earthy or somewhat lithographic appearance of some of 

 the beds, their pale colour, and their containing the large Rotalince so 

 frequent in the Subathu limestone and clay series, unite the formation, as 

 exposed here, with that of the Subathu series from the Indus to Murree, 

 if not further eastwards. 



Conditions. — The circumstances of deposition must with the advent 

 of this series have undergone still further change, the muddy ferrugin- 

 ous waters so general^ distributed becoming locally charged first with 



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