PART 3 .] 
Ho<)hts letter, Geology of Nicobars. 
59 
The occurrence hove of the persistent and well-marked band of laterite and its associ¬ 
ated white clay or steatitic breccia, passing conformably upwards into the Tertiary beds, and 
less regularly, but still with an appearance of transition, into some of the bedded traps 
below, though differing from certain of the facts observed in the country north-cast of Surat, 
may possibly modify some of the conclusions with regard to the moi'e obscure occurrence 
of the same three groups, i. the bedded traps, latcritic beds, and Tertiary rocks of 
Guzerat, or may, at least, confirm the impression of the volcanic activity which produced 
the bedded traps dating from early Tertiary times. 
If, in the absence of fossils, lithological similarity be admitted as evidence, it may be 
possible that some of the white felspathlc sandstones, considered as Upper Jurassic, overlying 
the Zamia-beds of Kutcb, may represent some of' the frequently similar looking Mahadeva 
or Bagh bods of Central India and the Nerbudda Valley. 
The evidence for a Jurassic age comes chielly from the lower part of the series, which 
is certainly marine so far, and the occurrence therein of a band of shale containing Zamm 
may bear the explanation before suggested, but at present the discussion of these points is 
almost premature. 
April, 1869. 
Much interest having been excited in the history of the Nicobar Islands, which have 
recently been taken possession of in the name of Her Majesty the Queen of England, I have 
thought it desirable to print here a brief summary of all tiiat is known regarding their 
geological structure. This could most effectively be done, by giving a translation of the 
reports of Dr. F. v. Hochstetter, who accompanied the Austrian ‘ Novara expedition as 
geologist. Dr. Stoliczka, long a colleague and friend of Hochstetter’s, has translated this 
report. The geological portion is given nearly at lull. The part relating to the vegetation 
and its connection with the soils, however interesting to those who have never seen a tropical 
vegetation, contains little that would be new to residents in this country; aud only a few 
extracts are given. A few remarks on springs and temperature conclude the paper. 
The geology of the Nicobars has many points of the highest interest to the Indian geo¬ 
logist, as bearing on the structure of the adjoining- Andamans, and the continuation of the 
same features into Burmah and northwards, on which connection some information will he 
given in future numbers. T. 0. 
Contributions to the Geology and Physical Geography of the Nicobar Islands, 
by Dr. F. von Hochstetter, (translated by Dr. F. Stoliczka, from the “ Voyage 
of the Austrian Frigate Novara round the world in 1857-1869." Geological part, 
2nd vol,, pp, 83-112. Vienna, 1866). 
The Nicobar islands (Pi. 3.) belong to an area of elevation which can be traced from tho 
Bay of Bengal far into the southern seas. Beginning under the 18th degree north latitude in 
the group of the Choduba and Regnain islands on tho coast of Arracan, passing through the 
Andamans and Nicobars, then continuing through Java, Sumatra, and tho south-western 
group of the Sunda islands, this line of elevation bends in an oblique S-forrn through 
New Guinea, to the north of the Australian continent, and forms in New Ireland, the 
Solomon Islands, New Hebrides mid New Zealand a curve, concave towards the west, the small 
group of the Macquarie islands being possibly considered as the extreme southern end of 
this curve. Winding from the northern into the southern hemisphere through 70 degrees "I 
latitude, this lino, or area, is characterized as one of elevation by two phenomena, totally 
different in Iheir nature, but nevertheless equally grand, and in certain respects related to each 
other. These phenomena are, first, tho activity of the interior of the earth, showing ilsell' in 
the volcanic action ; and secondly, the activity of the coralline animals, disclosing itsoll in the 
formation of that kind of coral reel's which Darwin has distinguished from the barrier or 
lagoon reefs under the name of fringing or coast reefs. 
Both phenomena, the volcanic action with its elevaLory power, and the formation of 
coast reel's, are, in certain respects, related In each other, as lias been placed beyond a doubt 
by Darwin's observations, although both do not appear together along all parts of this area- 
