ROCK FORMATIONS. — TERTIARY. 



75 



CHAP. 7.] 



submerged. In these upper beds only pebbles of trap^ agate, and sand- 

 stone, have been met with, in conglomeratic layers showing the uncon- 

 formity of that part of the series to the stratified traps, on the denuded 

 surface of which they sometimes rest. 



This unconformity has not been found among the lower beds of the 

 group already mentioned, nor yet between them and the nummulitic sub- 

 division, and is but obscurely traceable amidst the many irregularities 

 which accompanied the deposition of the soft uj)per rocks of Kutch. 

 The equivalents of these upper beds in the western portion of the 

 district may be certain thick conglomerates made up of older tertiary 

 rocks, sometimes wholly of nummulites washed from their original 

 matrix. The friable nature and sub-recent aspect of all these upper beds, 

 and the impossibility of tracing their uncertain stratification for any 

 distance, together with the general absence of organic remains, present 

 great difiieulties in attempting to classify them with accuracy. 



The sub-groups into which the formation has been divided provision- 

 ally are as follow : — 



Descending order. 

 Variable and inconstant deposits, including concrete tedsl Psobable thickitess 

 of great thickness. 



Soft sandstones, shelly, calcareous and quartzose grits, r 200 to 500 ft. 

 gravels and conglomerates mth trap pebbles and agates. 



Brown sands and sandstones with fossil timber. 



(Unconformity.) 

 A great thickness of clays and shales alternating with 

 sandy shales and harder bands of shelly limestone, or marls ; 

 a few nodular clay and conglomeratic beds. 



In the upper part fossils are most abundant, often forming 

 whole beds. 



The lower part is often rusty brown and sandy, with ferru- 

 ginous and lateritio bands and some conglomerates. 



Some of the sands are richly mottled and in parts white, 

 i. Some large bones, &c., in one of the lower conglomerates. 



( 7.5 ) 



800 to 1,200 ft. (?) 



