1844.] Recent Fossil Fresh-water deposit, fyc. 317 



making successive experiments, that the meteorological conditions be as 

 far as possible similar. The time of the year should be the dry season ; 

 and the time of day, sun-set and sun-rise. 



The plains and valleys of India are often covered with sheets of kun- 

 ker, sometimes upwards of 70 feet deep, overspreading places where 

 it could never have been deposited by rivers or rivulets ; and where 

 now, not a spring or drop of water is to be seen. Along the edges of 

 trap dykes, we occasionally observe mounds of kunker precisely resem- 

 bling those around the mouths of existing kunker-depositing^ springs, 

 but we look in vain for the springs that deposited the former. 



Still these dwindled remains of springs are generally to be found 

 where kunker prevails at no great depth from the surface, deprived 

 of their heat and of the greater part of their mineral character, which 

 renders the water better adapted for the use of man and animals. 

 Most of the native diggers in boring for a well, consider kunker as 

 almost a sure sign of the vicinity of water. If there can be any 

 doubt after what has been said of the certainty of the vast sheets of 

 kunker at present seen covering waterless plains, and the arid summits 

 of hills of S. India having been formed by springs, many of which are 

 now dried up or diverted, it will be removed on an inspection of a 

 vertical section of the rocks which underlie it. These, whether trap, 

 granite, the hypogene schists, sandstone or limestone, will be found 

 invariably to be penetrated by nearly vertical fissures, through which the 

 kunker appears to rise like trap in a dyke and to overflow the surround- 

 ing surface, and like trap, to introduce itself into any horizontal or 

 other seams, imparting the appearance of beds of kunker alternating 

 with gneiss, &c. On a more minute inspection it will be found, that 

 the kunker has in reality been precipitated chemically from the water 

 of springs that now, or formerly, found vent to the surface through 

 these fissures. The thermal waters holding the lime in solution as they 

 cooled in approaching the surface deposited the lime as they ascended. 



I had an opportunity in 1840, of studying the formation of travertine 

 in the old volcanic area around Rome, and found it to assimilate that of 

 the Indian kunker in all the leading facts. The calcareous conglomerates 

 at present forming along the shores of the Red Sea and Mediterranean, 

 are little different from the present kunkrous conglomerates of India. 



It may also be added, that the surface soils of S. India, whether of the 

 red alluvial, or the black regur, are frequently so strongly impregnated 



