DOAB SERIES. 



29 



upper part of the series. Conglomerate occurs locally and in one locality 

 a coarse volcanic agglomerate was noticed. 



The age of the series is doubtful, as no conformable junction with 

 underlying rocks has been observed, and it has been found, in upper 

 Saighan, distinctly unconformable to the supposed Fusulina limestone. 

 On the other hand it sometimes appears to be overlain conformably by 

 a plant-bearing series of middle Jurassic age (the Saighan series). 

 How far this appearance may be deceptive I have not been able to 

 determine ; in certain places there is apparently a well-marked uncon- 

 formity between the two series. The Doab series, however, is evidentlv 

 partly of marine and partly of sub-aerial origin, whilst the Saighan 

 series appears to have been deposited in fresh-water ; this would fullv 

 account for the apparently anomalous mutual relations of the two 

 series and there is no conclusive evidence of any serious time-break 

 between them. Consequently the Doab series is probably partly of 

 Jurassic and partly of Triassic age. No fossils have been found in it 

 in any part of the area that I visited, although some of the dark shales 

 seem admirably suited for their preservation ; but it is possible that 

 certain lamellibranchs collected by Mr. Griesbach in Chahil, may have 

 come from it (see infra, p. 31). It is unfortunate that I had no 

 opportunity of ascertaining the relationship of this series to the fossili- 

 ferous beds of the Fusulina limestone ; in several localities which 

 happened to be accessible to me I had hoped to find both series, 

 but they were hidden at the crucial point by the cap of Upper 

 Cretaceous limestone which covers so much of this part of Afghanistan, 

 lying unconformably on, and hiding, all older formations. The most 

 favourable locality would probably be the deep river-gorge between 

 Bamian and Saighan, which I was unable to visit and which is said to 

 be passable only in the winter when the water is at its lowest. 



In connection with the question of the age of the Doab series, it 

 is interesting to note that the late Dr. A. von Krafft, who visited 

 Darwaz in the year 1898, met with a volcanic series of which the lowest 

 beds were interstratified with Fusulina limestone. From the writings, 



