CHAP. 8.] -, 83 



Chapter VIII. — Summary of the succession op the different forma- 

 tions AND THE conditions ACCOMPANYING THEIR ACCUMULATION. 



It may be advantageous here to recount briefly what may be learn- 

 ed from the formations previously described as to the conditions and 

 order of sequence under which they originated. 



Although no basement-junction of the jurassics has been found, 



it may fairly be inferred that they rest some- 

 Unconformity of lower 

 Jurassic and metamor- where upon the metamorphic rocks of which a 



phic rocks. 



portion is exposed in Nuggur Parkur; for some 

 of the lower beds in the island of Bela and elsewhere have been found 

 to contain a few rolled syeniticj hornstone, quartzite and other me- 

 tamorphic, pebbles, pointing to an unconformity and a period when 

 the metamorphic rocks underwent denudation simultaneously with the 

 deposition of the lower Jurassic beds. The scarcity of these pebbles 

 may also indicate both distance from their source and probably a con- 

 siderable accumulation of the marine Jurassic beds earlier than those 

 in which they have been found. 



The shales and sandstones of this lower Jurassic period of Kutch 

 are proved by their fossils to have been mainly of marine deposition, 

 if not entirely so, the few cases in which terrestrial forms have been 

 found interstratified pointing to the supposition that these land fossils 

 were washed into the seas or estuaries of the time. 



The upper Jurassic beds containing both marine and terrestrial 



fossils present no change of aspect sufficient to in- 

 Upper Jurassic. 



dicate that they were of lacustrine origin or depo- 

 sited mostly in fresh- water, so that the same reasoning with regard to 

 the presence of terrestrial plants may be applied to this group. In its 

 general aspect this part of the formation has less of a deep-sea character, 

 less appearance of tranquil deposition than the lower beds, and its 



{ 83 ) 



