CHAP. 6.] THE STRATIFIED TRAPS. 61 



attention to the frequent occurrence of scoriaeeous volcanic asli^ but this is 

 certainly very different from the well stratified materials of some of the 

 aqueous iutertrappean beds. 



These beds of volcanic ash^ so common in the formation, however, 



may represent the material that would have formed cones if the eruption 



of the traps had not been sub-aqueous, or sub- 

 Volcanic ash. 



jected to conditions which prevented either their 



formation or preservation ; and the occurrence of the ash in thick beds 



instead of thin laminse may be merely the form of their distribution 



underneath water in contradistinction to that which they would have 



assumed from falling in showers through it, or from having been 



brought down by intermittent streams. 



The absence of the remains of old cones and littoral tufaceous rocks 



may indicate perhaps that the mass of the traps was accumiJated at 



great depths, or that they found their way to the 

 Absence of Tufa, &c. 



bottom of the sea through dyke-fissures or other 



vents than craters. Otherwise it seems extraordinary that some 



remnants of the cones and craters have not been discovered in position. 



It has been suggested (by whom is uncertain) that the sources of 

 Vents in tlie sea and the traps were a line of volcanic vents once exist- 

 ing where the sea is now to the westward of their 

 area; and a line of vents has also been said to occur parallel to, and beneath, 

 the Western Ghats in the Konkan (Kokan) ;* but from neither of these 

 sources can be imagined sub-aerial flows reaching some 500 miles to the 

 east ; while better evidence for their origin is aflPorded by the numerous 

 sources of igneous protrusion found within, or in the vicinity of, the 

 traps or the country from which they may have been removed. 



* Eemarks upon tlie basalt dykes of tlie mainland of India opposite to the Islands 

 of Bombay and Salsette, by Geo. T. Clark, Esq., ¥. &. s., Quarterly Journal, Oeol. Soc, 

 London, Vol. XXV, Pt. 2 (No. 98, p. 164). 



( 61 ) 



