1889.] Address. 91 



The enquiry into the quality and extent of the Manganese deposits 

 in the Jubbulpore District has been completed, with an estimate of 

 over 75,000 tons of available pyrolusite ; the manganese hematite being 

 considered practically unlimited in its extent. The geological inter- 

 est attaching to this enquiry lies in the question of the origin and mode 

 of distribution of the pyrolusite, which also partly occurs in what may 

 be called a manganese laterite, in contrast to the ordinary or ferruginous 

 rock of that name. The distribution of the pyrolusite in this laterite 

 and other superficial deposits, or in the outcrops of the rocks, is attribu- 

 table to a deposition by leaching out of a manganese carbonate from the 

 adjacent manganiferous hematites ; while the occurrence of manganese 

 laterites points to a probably more extended, though local, distribution 

 of manganese ores among the widely distributed laterites in the penin- 

 sular region than has been previously anticipated. 



During the enquiry into the conditions of the Sapphire-bearing 

 rocks of the Zanskar district in Kashmir, a very interesting* confirmation 

 was made of the find of nummulites by Dr. Thompson in 1852 ; more parti- 

 cularly so as this occurrence which had been adopted by MM. d' Archiac 

 and Haime in their classic work on the Numnmlitic fossils of India, had 

 been since questioned by Mr. Lydekker in his " Geology of Kashmir." 



A Memoir on the Physical Geology of the Sub-Himalaya of Garh- 

 wal and Kumaun, following on the surveys of Mr. 0. S. Middlemiss, 

 will shoi'tly be published. The more interesting subjects treated of in 

 the author's general considerations, are: — absence of metamorphism ; no 

 evidence of glacial conditions ; each reversed fault represents an ancient 

 shore-line, or mountain-foot, i. e., a limit of deposition; contrast of the 

 south face of the Himalaya with the eastern aspect of England ; the 

 disturbance of the Sub-Himalayan rocks not representative of that of 

 the older rocks ; abstract theories of mountain-making ; consideration 

 of Mr. T. Mellard Reade's theory and the Rev. 0. Fisher's " Physics of 

 the Earth." 



The oil region of Makum, in Assam, has undergone additional exa- 

 mination by Mr. R. A. Townsend, Superintendent of Petroleum-Works 

 in Baluchistan : his report of the oil-shows and the possibilities of this 

 tract being most favourable. A certain amount of caution must, how- 

 ever, be observed in forming an estimate of the value of the oil, for the 

 present, at least ; because the results obtained in the Geological Survey 

 laboratory, from examination of the sample of oil brought down by 

 Mr. Townsend, agree very closely with that already given by Prof. 

 Bo verton Redwood, (Cantor Lectures on Petroleum and its products) from 

 an assay of petroleum from Assam, where he obtained no percentage 

 of burning oil, 94*2 per cent, being merely lubricating oil. It must be 



