CHAPTER XI. 



SUBAERIAL FORMATIONS AND SOILS. 



I. — SuBAERiAL Formations. 



"Within the area treated in this report the suhaerial formations 



which require to be noticed are those which have 

 Principal varieties. 



resulted from the reproductive action of various 

 atmospheric agencies ; such as (a) cong-lomerates formed by the cemen- 

 tation of loose materials by deposition o£ argillaceous and ferruginous 

 cements in a simply mechanical way, or (5) similar deposits cemented 

 together by the chemical precipitation of calcareous matters, and tufas ; 

 or other formations also resulting from the same class of agencies, such 

 as purely pluvial aggregations (<?) and blown sands (d). Yet another 

 class (e) is that of formations greatly changed by the percolation 

 of atmospheric moisture in large quantities as the ' iron clay ' 

 and other lateritoid rocks ; in these the change is both chemical and 

 mechanical. 



The first and last of these five classes of subaerial rocks are most 

 largely represented in the South Mahratta country. Several very re- 

 markable instances of cementation of talus debris will be described in 

 the following pages. Tufas, though not uncommon, are, as a rule, of small 

 importance, and no blown sands of importance were met with anywhere, 

 while the rocks which come under class (e) have already been fully 

 dealt with in Chapter VIII. 



a. — Subaerial Conglomerates and Breccias. — Cases of the cementing 



^ of talus and of debris of quartzites of the Lower 

 Conglomerates formed 



by ferrugino-argillaceous Kaladgi series by the deposition subaerially of fer- 



cement. 



rugino-argillaceous matter were noticed at Sona- 



pur a little south-east of Katharigarh, and three miles further west on 

 ( 244 ) 



