260 GEOLOGICAL SURVEY OF INDIA. 



Of the work achieved during 1883 Mr. Griesbach's was probably 

 the most interesting, dealing as it did with the main Himalayan 

 range and its grand formations. He completed the survey of the 

 Hundes basin to its western limit on the flanks of the gneissic mass 

 of the Porgyal mountain which separates Hundes from Spiti. For 

 some important horizons he satisfied himself of the identity of the 

 sections in Spiti (as partly determined by Dr. Stoliczka) and those 

 in Hundes. From this region Mr, Griesbach had to hurry late in 

 October to join the expedition to the Takht-i-Suliman, on the 

 North-West frontier.* This remarkable peak consists of the 

 cretaceous sandstones with limestones described by Mr. Blanford 

 as forming the crest of the range 80 miles to the south. f 



In Jaunsar, in the Lower Himalayas, Mr. Oldham succeeded in 

 introducing two unconformable and almost wholly detached groups 

 above the Deoban limestone where a great gap had always existed 

 between the tertiaries in the Simla section and the Krol group, for 

 which no age later than the trias had been conjectured. Further 

 researches into the character of the granitoid gneiss of the 

 Himalayas were made by Colonel McMahon, leading to the con- 

 clusion that much of it is intrusive and must properly be called 

 gneissose granite. 



An important contribution to the literature of the year was 

 Mr. Lydekker s volume on the north-west Himalayas (" Memoirs," 

 Vol. XXIL), the researches in the field for which had been concluded 

 two years previously. 



Mr. La Touche was to have taken up the examination of the coal 

 field in the G-aro hills, his preliminary visit to which was described 

 in the " Records," Vol. XVI., page 164, but instead he was deputed 

 to accompany Colonel Woodthorpe's party in the exploration of the 

 Dehing basin, a region of much interest, as it probably reaches 

 beyond the zone of tertiary rocks fringing the Upper Assam valley 

 and beyond the range of the Arakan-Manipur axis. Unfortunately 

 this plan was interrupted by the Aka raid, the party being diverted 

 into that territory and Mr. La Touche with it. The ground is 

 Himalayan ground proper not far to the west of the Daphla 

 district, visited by Colonel Godwin- Austen in 1865, and probably 

 like it in structure. 



The eastern parts of the Madura and Timievelli districts were 

 examined by Mr. Foote, and a sketch of the geological features of 



* See above, p. 147. j " Memoirs," Vol. XX., Part 2. 



