4 MIDDLE MISS: THE GEOLOGY OF IDAR STATE. 



In the above sequence of formations it will be seen that 

 immediately below the surface soil, blown sand, alluvium and 

 other river deposits of Recent age, the whole of the Tertiary system 

 of India is conspicuous by its absence, a feature in which the present 

 described area agrees with the rest of Peninsular India to the south 

 (of which it constitutes a sub-marginal part), and is in strong con- 

 trast with all Extra-peninsular regions, including the neighbouring 

 areas of Catch and Kathiawar which lie west and south-west of 

 it. It is possible there may be some slight exception in the bed 

 of the Sabarmati River, where some lateritised shales and sand- 

 stones have been interpreted by Foote (Geology of Baroda, p. 65) 

 as doubtfully Eocene, and also at the locality near Dedhrota which 

 is marked Nummulitic limestone on Kishen Singh's ma]) ; but 

 these occurrences have not been substantiated by later work. 



Although no laterite or Deccan Trap is actually known in the 

 described area, these formations arc plainly developed a little 

 further south in the Meshva and Majham drainage areas on the 

 road from Talod railway station to Modasa. Probably both these 

 formations, that are so characteristic of the neighbouring penin- 

 sular areas to the east and south-east, have here just found one 

 of their limits of extension on the border of Idar State, although 

 they are well represented further west and south-west in Cutch and 

 Kathiawar. 



Of Mesozoic rocks below the Deccan Trap, the sole formation, 

 rather scantily represented, is the Ahmednagar Sandstone of pre- 

 sumed Umia age (Jurassic to Cretaceous). Unfortunately it has 

 yielded no fossil remains, and we can only hazard a guess from 

 its lithological features that it more nearly approaches in character 

 the rocks of Cutch and Kathiawar, of generally marine facies, 

 than those of the uppermost Gondwanas. I do not think Kishen 

 Singh's reference to these as Vindhyan need be seriously enter- 

 tained. 



Below this, again, the Geological Record is entirely unrepresented 

 by any fossiliferous deposits, either marine (of extra-peninsular 

 type) or freshwater (Gondwana or peninsular type) ; and the hiatus 

 in sedimentation is continued by the absence of all the great Vindh- 

 yan formation, both Upper and Lower. Furthermore, the rocks 

 next in order below, which do make their appearance, and which 

 constitute the bulk of the solid geology of the State, are so lacking 

 in data for correlation purposes, that beyond enabling one to place 



