CHAP. 7.] ROCK FORMATIONS. — ALLUVIUM. 81 



times nodular and kunkury, with large fossil oysters (0. lingwla ?) not 

 unlike some of those now living on the coast of Kutch. As these beds 

 are by no means constant, their further description will be better 

 reserved for the part of this report dealing with local details. 



Alluvium. 

 The alluvium of this country is the result of degradation of the 

 local rocks. As most of it overlies the tertiary beds, which must have 

 been heavily eroded to form the plains, it consists largely of materials 

 derived therefrom, frequently mingled with travelled fragments brought 

 by rivers from the hills. Much of it is a kunkury deposit or mottled 

 clay with red blotches and quartz grains, resembling a newer tertiary 

 stratum, and thought by Mr. Fedden to belong to an older period than 

 the rich brown loamy alluvium, which sometimes approaches to the 

 character of ' regur.' 



Very generally distributed over the hilly country, is the sub-recent 

 calcareous deposit already alluded to. The white sandstones of which 

 it consists are sometimes sufficiently coherent to be used for building, 

 and it is very commonly burned for lime all over the province. No 

 fossils have ever been found in it, but on some slabs, from the deposit in 

 Western Kutch, tracks of Crustacea or of annelids have been observed. It 

 is not limited to a uniform level in its various situations, having been 

 met with in the low ground at the foot of hills bordering the Runn, as 

 well as high in their glens. Its aspect is always very much the same, 

 though its texture is varied, being sometimes conglomeratic or finely 

 oolitic, and generally it presents much oblique lamination.* 



• Possibly this may be the rock alluded to by Carter in the ' Summary', Geological 

 Papers, Western, India, ^. 5Qi?i, as raeni\onei by Colonel Sykes, Geological Society Transac- 

 tions, Vol. V, p. 716, under the name of Oolite, and considered by Dr. Carter to represent 

 the 'Miliolitic formation" of the Arabian Coast. If so, it does not contain organisms in 

 Kutch so far as microscopic examination goes, 



I ( 81 ) 



