the Eastern Portion of the Basaltic District of India. 655 



as calcareous tuff in the water-courses. Masses of the same substance, several 

 feet in height, project from fissures in the rock, or compose conical eminences 

 of white " Kunkur," which are scattered over the black jjasaltic plains. 



Proceeding a little further towards the Pindee hills, in which the princi- 

 pal of these streams takes its rise, sandstone appears on the south bank of a 

 ravine; and on the opposite side, at a lower level, the "argillaceous lime- 

 stone" so often mentioned, has been raised by some violent forces into irre- 

 gular gothic arches, overlaid by partially broken but horizontal strata. The 

 spaces within the arches are filled with fragments of the same rock forced 

 from below. Hot springs, having a temperature of 87°, rise through the lime- 

 stone, and globules of gas escape from round holes in the debris and mud 

 covering the bottom of the ravine. On endeavouring to collect a quantity of 

 the gas, there were found to be considerable and irregular intervals between 

 each jet of air. A recent calcareous sandstone is formed in the bed of the 

 stream, by the debris derived from the quartzose sandstone of the southern 

 bank being agglutinated by the carbonate of lime of the springs. 



A range of low hills having rounded summits, with conical elevations pro- 

 jecting from their sides, runs in a north-west direction, three quarters of a 

 mile from the hot springs. The cap of these hills, where the Pindee Ghat 

 passes over them, consists of the argillaceous limestone, and the large slabs of 

 which it is composed, are fissured in various directions, slightly convex up- 

 wards ; and when taken in the mass, they have an anticlinal dip. On the sum- 

 mit, the strata are horizontal and in several places are remarkably altered, the 

 argillaceous and siliceous ingredients having arranged themselves into a black 

 chert, and a mixture of calcareous matter with streaks of a white or pale blue 

 enamel resembling calcedony. The central parts of these bands are com- 

 posed of minute quartz crystals ; and irregular drusy cavities, coated with 

 amethystine quartz, occur in the blackened flinty portions. There cannot 

 be a clearer indication of the action of heat on a rock of a mixed character 

 than this, even when seen in hand specimens. The whole of the base of the 

 hill is composed of the usual black concentric basalt, the nuclei of which are 

 exceedingly hard and contain much olivine ; and to its intrusion the altera- 

 tion of the limestone, with its separation from the strata below, is, without 

 donbt, to be ascribed. 



Many hills composed of concentric basalt are scattered over the neigh- 

 bouring country, in insulated masses or long ranges rising in terraces, and 

 having flattened summits. The sides of the hills between the terraces are 

 steep, and their outline is well defined ; the rock also is black and devoid of 

 vegetation. The terraces occur at very different levels in different hills^ rising 



VOL. V. — SECOND SERIES. 4 C 



