i88 
Ilecorch of ihe Geological Survey of India, 
[vOL. XI. 
The Mud Volcanoes or Ramri and CHEHunA, hy F. R, Mallet, F.G.S., 
Geological Survey of Tndia. 
During a recent tour througli Ramri and Choduba, the main object of which 
was to examine and report on certain coal-beds said to exist in the islands, I had 
an opportunity of visiting the greater number of the mud volcanoes, tho occur¬ 
rence of which has long been known, and brief allusions to which are to be found 
in many standard works on volcanic phenomena and on general geology. 
The original sources of information referred to in such works consist mainly 
of a “ Report on the Island of Chedooba” by Commander E. P. Halsted,’ which, 
amongst other matter, contains valuable and, with but few exceptions, 
accurate observations both on the volcanoes, and on the elevation of Cheduba and 
tho neighbouring islands which has occurred wuthin tho last two centuries. 
Besides the above, a few notes on the volcanoes of Ramri may be found in Lieute¬ 
nant Foley’s Jouimal of a tour through that island, and in a paper on some coal 
which had recently been found at Kyauk Phyu.® Dr. Spry, also, has briefly 
alluded to one of the volcanoes near tho last named place in his account of 
“ A three weeks’ sail in search of health.”* * Notices by Captain J. Russell of a volca¬ 
nic island which rose from tho sea near Cheduba in 1843 and subsequently disap¬ 
peared ; of a fire at .sea witnessed from Kyauk Phyu in 1846, and conjectured to 
have been volcanic; and by Major Williams of an eruption from one of the 
Kyauk Phyu volcanoes in 1846, have also been published." To all the above 
records I shall subsequently have occasion to refer. 
The allusions to Ramri and Cheduba by systematic writers refer mainly to 
the fact of tho mud volcanoes there being at, or near, the end of that great line 
of volcanic vents which may be traced thence southwards by Narkondam and 
Barren Islands, in the Bay of Bengal, through the entire length of Sumatra, 
Java, and the eastern island.s of the Sunda group. By some, indeed, this line is 
considered only a portion of a still greater one which, sti-etching from Tierra 
del Fuego noidhwards, along tho western fringe of South and North America, 
is continued through tho Aleutian Islands, Kamschatka and .Tapan to tho 
Phillipino and Molucca lsland.s. There it is considered to divide into two, one 
branch running south-east through Papua, tho New Hebrides and New Zealand ; 
the other passing, as before said, through Java and Sumatra, and having its 
furthest limit in Arrakan and Chittagong.* 
’ Jounial As. Soo., Bengal, X, 1841, pp. 319, 419. 
= Ibid., II, 1833, p. 595; IV, 1836, p. 20. 
* .louniiil As. Soc., Bengal, X, 1841, p. 138. 
^ JSiVi!., XII, 1843, p. 1114; XIV, 1845, Proceedings for Pelmiary; XV, 1846, Pi’ocoeilmg.s 
for November. 
, Scropc on volcanoes, p. 12; Lyell's principles, lOtli edition, 11, p. 585. There is a ‘ true’ 
volcano, called Pnppa-doung, about 30 inilos o.ast of tbo Trrawadi, in latitude 21°, but it lias been 
long extinct. It bas been described by Mr. W. T. Blanford, who believes it to be of Mioconx) or 
Pliocene age; more probably tbc latter (Jour. As. Soc, Bengal, XXXI, 315). 
