CHAP. 6.] THE STRATIFIED TRAPS. 63 



Under the supposition that both elevation and depression, to the 

 extent of submergence, accompanied the volcanic activity of the 

 region, all its features can be explained : cones having been thrown up 

 in shallow water or on land during submergence, it is conceivable 

 that many of them would be swept away by wave action, and thus 

 the earliest traces of the sources of the igneous materials might be 

 destroyed. Subsequent eruptions in the sea may not have formed 

 cones, and later still elevation mi'ght occur, or the accumulating flows 

 at last raise themselves above water when lacustrine deposits could be 

 formed. 



The high temperature of the water and unsuitable nature of the 



land might have prevented the existence of organic 

 Temperature. 



life throughout most of the period; while the 



breadth and evenness of the slightly elevated tracts would tend to 



conceal the limits of those localities which may have been sub-aerial, 



subaqueous, or submarine, except where fossils could be found, 



there being nothing sufficiently marked in the general characters of 



the flows to distinguish one set of conditions from the other, any more 



than there is to show how far the eruptions of the period may have been 



strictly contemporaneous.* 



There being nothing impossible in the idea that these Kvitch traps or 

 lavas may have spread themselves out partly on 



Conclusion. 



land but mostly under water, the materials having 

 risen through outlets possibly as numerous beneath the whole area as 



* It would be interesting to compare with the Deccan traps the features of the 

 smaller basaltic tracts of Scotland and the north of Ireland. The latter, with an area of 

 1,200 square miles and thickness of 900 feet, is similarly of supra-cretaceous position, has 

 no volcanic cones, is composed of a variety of amygdaloidal and columnar layers with beds 

 of ashy, ochreous or earthy nature interstratified. It has yielded fossils of tertiary age, 

 and is stated by the late Professor Jukes " to have been probably of submarine formation." 

 — (Jukes' Manual of Qeologi/, p. 331.) 



( 63 ) 



