30 MIDDLEMISS: PHYSICAL GEOLOGY OF SUB-HIMALaYA. 



Although, for reasons given above, the detailed description of the 

 Sirmur series, num- nummulitics will be left until the Himalayan 

 mulmc stage. group of formations can be taken in hand, I 



may make a few remarks about their petrology here for the sake of 

 uniformity. They are characterised by being thinner bedded and 

 less massive than any of the previously described formations. A piso- 

 litic iron ore bed is found at the bottom of the series in some places, 

 just as in the area examined by Mr. Medlicott. This passes upwards 

 into grey, and sometimes slightly purple, shales and sandy beds ; with 

 earthy calcareous nodular beds, and other thin strings of purer dark 

 blue-grey limestone, containing nummulites and other foraminifera, 

 besides mollusca and fragmental vertebrate remains. Still higher in 

 the stage, the rock becomes marked by more shales, the limestone 

 dies out, and sombre purple, grey, and greenish-grey coloured shales 

 take their place. Some few purple, gritty bands next come in, and 

 suggest a beginning of the Dagshai stage in this locality. The whole 

 of the Sirmur series here exposed is very thin, becoming thinner 

 as we travel east of the Ganges. A few hundred feet is the maximum 

 attained. 



CHAPTER IV. 



DISTRIBUTION AND STRATIGRAPHY. 



In describing the distribution of the different rock stages, it will 

 be well to take separate portions of the Sub-Himalayan zone, bound- 

 ed in a more or less natural way, and detail the geology of each. 

 Certain considerations also make it advisable to begin in the middle 

 of the region where the stratigraphical relations are the simplest, 

 namely, the Kotah dun, and to travel in imagination west-north- 

 west ; taking up one after the other of the minor duns and the 

 intervening country until Hardwa*r is reached. After this the rest of 

 the Sub-Himalayan country of East Kumaun will be gone over in the 

 opposite direction as far as the Sa*rda R. 

 ( 88 ) 



