YOUNGER TERTIARY— SIWALIK. 83 



overlies a lower band of nummulitic limestone. The upper lime- 

 stone is 150 to 200 feet thick, the sandstone 50 feet and the lower 

 limestone about 100 feet thick. The whole series dips from 5 to 

 20 S. E. Below the lower limestone comes the mottled trap band, 

 which rests on the gneiss. 



Sandy nummulitic limestone, with a low easterly dip, rests on the 

 mottled trap of the Deopani, but it is only seen in one or two places. 

 The last exposure of the nummulitics occurs in the Boro Neoria at 

 Pangso, where a few feet of sandy and light-blue limestones are 

 seen, lying horizontally in the stream bed. 



The total absence of sections, continuous from top of base, of the 

 Summ nummulitic rocks, makes it impossible to do 



more than estimate their composition and thick- 

 ness. The series seems to vary rapidly, sandstone and limestone 

 replacing one another frequently. Northwards, as on the Haria 

 Jan, the nummulitic band reaches some 300 feet in thickness, and 

 is composed of limestone with an intermediate band of sandstone. 

 Near Miji the thickness must be rather greater, probably 200 feet 

 of sandstone overlying about an equal thickness of limestone, with 

 some sandstone partings. Southwards the thickness decreases again 

 to about 200 feet, of nodular limestone overlaid by coarse sandstone. 



No actual junction of the nummulitics with the lower rocks is 

 seen, but they always rest, either horizontally or with gentle dips, 

 on the gneiss, or upon the overlying mottled trap and white chalk- 

 like rock. 



No trace of fossils is met with in any of the sandstone bands ; 

 and the limestones, though frequently made up of nummulites and 

 bivalve shells, do not yield any well-preserved fossils. 



North of the Boro Neoria the nummulitic band is apparently 

 overlapped by the grey clay-shales of the younger tertiary. 

 Younger Tertiary— Siwalik. 



At the two places where contact-sections between the older and 

 younger tertiary beds are seen — on the Haria Janjand Jamuna— 

 G2 ( 83 ) 



