On the Geology of Cutck. 



[Oct. 



Denodur FJill, an extinct. Volcano. — Of the detaclied hills, the eleva- 

 tion of which I conceive to be dae to volcanic influence, the principal is 

 that called Denodur, and is situated near the shores of the Runn. It 

 is the largest and highest hill in the country, and is evidently the re- 

 mains of an extinct volcano, an irregular crater being still visible. In 

 the north side is a large gap, reaching nearly to the foot of the hill, but 

 partially blocked up by a lower ridge, or a kind of traverse. Its western 

 flanks are composed of a series of ridges of laminated clay and loam, 

 interspersed with flat, angular fragments of slaty sandstone and slate- 

 clay. The surface of some of these ridges is smooth, consi;^ting either 

 of thin slabs of slate-clay, or of thicker slabs of a very conipact, cry- 

 stalline, and slightly calcareous stone, the same as that which overlies 

 the laminated series, and forms the walls on the Runn, &c. Near the 

 base of the hill and for more than two-thirds up its side the construc- 

 tion alters, being composed partly of a loose saadstotie, an-l partly of 

 the calcareous grit, containing imbedded, angular fragrnentt; of basalt ; 

 the uppermost part is a p;^rpendicular wall of basalt, which, apparently, 

 continues all round the top. A stream of very compact basalt runs 

 past its north-western flank, and in other places. Numerous small conical 

 hills, composed of horizontal layers of limestone giit, or of basalt, are 

 scattered over its sides, and its base is covered with a thick mould, 

 formed of decayed vegetables, with eirthy matter. Nowhere did I iind 

 any traces of recent disturbance, although the people of the neiglibour- 

 hood, particularly the Jogees, or religious devotees, who inhabit a te;Tiple 

 on its northern flank, asserted that tire issued from it during the earth- 

 quake of 1819. If it did, there would, of course, be some signs of it re- 

 maining ; but I was unable to penetrate into the interior of the hill, 

 owing to the dense Bauble Jungle, or crooked thorn tree with which it 

 is covered. 



Not far from this place, and adjoining the village of Nuckutrana, a 

 hill of some size, called Ungia-soorud, the elevation of which has also 

 been effected by volcanic agency. The flanks and base are composed of 

 a very loose, friable, calcareous sandstone and grit, apparently stratified, 

 but inclined at all angles; and the remainder consists of very compact 

 basalt. The hill is divided into two parts by a narrow, tortuous cleft, 

 the si'les of which are nearly perpendicular, and composed of irregularly 

 triangular prisms of basalt. The cleft is not more than four feet wide at 

 the bottom, though it is somewhat broader ut the top ; and as it passes 

 completely through the hill, we must suppose the whole to be similarly 

 composed. 



