CHAP. 5.] EOCK FORMATIONS. LOTVEE JUEASSIO. 49 



Kattiwar, it may not be too much to presume that metamorphie rocks 

 extend far underneath the Runn and Kutch, supporting the whole 

 of the secondary and newer formations. 



JUKASSIC. 



This is the most largely developed formation in Kutch. Its charac- 

 ters are not^ however^ constant; considerable differences being found 

 in the lateral extension of certain of the beds. It is not easy to give 

 a general description of rocks so varied and yet 

 Difficulty of a general go similar in their general aspect. Over laro-e 



description. o i j, 



spaces the same varieties prevail to a degree which 

 often renders it difficult to believe that they are not repeated; and 

 the transition from one set of characteristics to another is so 

 gradual, and accompanied by such alternate recurrence of slightly 

 peculiar beds, commonly met with among one or the other, that the 

 close determination of definite zones on purely petrological grounds 

 is impossible. 



With all this similarity there is a broadly marked difference between 

 the general character of the lower and the upper portions of the formation 

 which has led to its division into two groups, these being understood to 

 have no rigid line of demarcation between them. 



Lower Jurassic. 



These rocks are chiefly distinguished by the large quantity of 



argillaceous beds which they contain, and which. 

 Lower Jurassic. 



weathering down, give rusty orange tints to 



the (usually hilly) parts of the country formed of them. Among 

 them are also to be found hard blue and gray quartzose layers, some 

 strong cream-colored sandstones, blue, black and gray ; sometimes gyp- 

 seous shales, which wasting leave the ground covered with small red 

 ferruginous nodules ; certain buff orange and bluish or gray close earthy 

 9. ( 49 ) 



