Book Title: Indian Antiquary Vol 58
Author(s): Richard Carnac Temple, Charles E A W Oldham, S Krishnaswami Aiyangar, Devadatta Ramkrishna Bhandarka
Publisher: Swati Publications
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THE INDIAN ANTIQUARY
[ August, 1929
sandstone is the characteristic rock of the neighbourhood and is generally, if not always, non-calcareous. In the Archipelago and over a large area in the Andamans, the islands are formed of soft limestones made of coral and shell sand, soft calcareous sandstones and soft white clays, with occasionally a band of conglomerate. Green and red jaspery beds, similar to those of Manipur and Burma and the Nicobars are found, which may belong to the same scrics as the sandstones and shales. On Entry Island in Port Meadows are beds of probably volcanic origin, perhaps later than the Port Blair sandstones. Intrusive rocks of the serpentine series and a scoriaceous rock rosembling lava occur in the Cinque Islands, Rutland Island. and in spots on the South and Middle Andamans. Hard breccias of volcanic origin are found at Namûnaghar in the Penal Settlement and yield an excellent building stone. Good red clay for bricks is found abundantly in pockets. Lime of the best quality is obtained from old coral, but a workable limestone cxists in limited quantitics. A pretty reddish building marble is also found. Red ochre (koiob) is found in considerable quantities in pockets and used, when mixed with garjan oil, as an excellent covering for shingled roofs. Mica in probably workable quantities has been found about Navy Bay Hill in Port Blair Harbour.
A theory of a still continuing su beidence of the islands was first formed by Kurz (Vegetation of the Andamans, Govt. Report, 1890) on his investigation of the vegetation in 1866 and was confirmed by Oldham in his Report on the Geology of the Andamans of 1884, though with some reluctance owing to the fact that the Arakan Coast to the north and the Nicobars Bhow signs of recont clovation. The subsidence seems to be of recent origin, and signs of its continuance, most markedly on the East Coast, are to be found at several places :-Port Mouat, Ranguchång on the East Coast of the South Andaman near Port Blair, Outram Harbour and Havelock Island in the Archipelago, the northern ends of the Little Andaman, the North Sentinel, and the North Andaman, The extremely interesting islands of Narcondam and Darren Island are volcanoes of the general Sunda group, the extinct volcano of Narcondam belonging apparently to what is known as the Pegu group and the quiescent Barren Island to the Sunda group proper. Barren Island was last in eruption in 1803, but there is still a thin column of steam from a sulphur bed at the top and a variable hot spring at the point where the last outburst of lava flowed into the sea, showing a temperature of 107° Fahr, at the erd of the 19th century.
Although the Andamans lie along, or at any rate are close to, a recognised subterranean line of weakness, earthquakes of great violence have not so far, in the short time of British occupation, been recorded. Recorded dates of earthquakes are August, 1868; February, 1880; and then shocks at times till December 31st, 1881 ; February, 1882; August, 1883; July, 1886; July, 1894 ; October, 1899. The sound of the great seismic disturbance in the Straits of Sunda on August 26, 1883, was heard at Port Blair at 9 P.M. of that day and the extra tidal waves caused thereby were felt at 7 A.M. on the 27th. The great Assam Earth. quake of 1897 was not felt at all. It is possible that the reason for the Andamans escaping violent earthquakes, while the Nicobars are subject to them, is that they are just off the line of greatest weakness, which may run from Sumatra through Great and Car Nicobar, Barren Island, Narcondam to the Arakan Yoma.
The marine fauna of the Andamans is of unusual interest and a projected aquarium on Ross Island would have proved of great scientific value had it been carried out. On examination the marine life goes to show what other physiological facts have proved--the close connection of the Islands with both Burma and Sumatra and the distant alliance with the Indian Peninsula. The land fauna, in several particulars, shows that the Andamans are closely allied zoologically with their neighbours, Arakan and Burma.
The economic zoology of the islands has been thus summarised by Major A.R.S. Anderson I. M. S., Principal Medical Officer of the Islands at the time of the Census. "The coral reefs and dead shells afford an immense field for obtaining a very fine quality of lime, which
