36 BLAXF0RD : GEOLOGY OF WESTERN SIND. 



The fossils of the Cardita beaumonti zone require much fuller examin* 

 ation and comparison than they have hitherto received ; but sufficient has 

 been ascertained to show that they have a distinctly cretaceous character, 

 but that nevertheless they have strong tertiary affinities. 



A bed of very similar mineral character, the olive group of Mr. Wynne/ 

 occurs at the base of the tertiary formations in the Punjab Salt Range, 

 and the fossils, amongst which Cardita beaumonti is also found, have for the 

 most part, in Dr. Waagen's opinion, a tertiary facies, but include one 

 Olive group of Pun- species of Ammonite. There is every probability 

 3 that the olive group of the Punjab corresponds 



to the Cardita beaumonti beds of Sind, and although in the preceding 

 table the latter group has been classed as cretaceous, this classification must 

 be understood as only temporary, for the thorough examination of the 

 fossils may show that the preponderance of affinities is really very ancient 

 eocene, or absolutely intermediate between the oldest tertiary and the 

 newest cretaceous formation hitherto known. No corresponding group has 

 hitherto been recognised in Baluchistan or in the Western Punjab south 

 of the Salt Range. 



2. Deccan trap.— Mention has already been made of one bed of basalt 

 intercalated in the sandstones above the hippuritic limestones : a much 

 more important band of the same igneous rock has been traced, resting 

 upon the Cardita beaumonti beds, throughout a distance of 22. miles from 

 Ranikot to Jakhmari, about 17 miles south of Sehwan, wherever the 

 base of the Ranikot group, the lowest tertiary formation, is exposed. 

 Position and thickness Tne thickness of this band of trap is trifling, and 

 of tra P- varies from about 40 to about 90 feet. Ap- 



parently in some places the whole band consists of two lava flows, 

 similar in mineral character, except that the upper is somewhat 

 ashy, and contains scoriaceous fragments; the higher portion of 

 each flow is amygdaloidal, and contains nodules of quartz, chalcedony, and 

 calcite, and in places the nodules are surrounded by green earth, as 



1 Mem. Geol. Sur., India, xiv, p. 103. 



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