CirAP. VI.] TRICHINOPOLY DISTRICT— OOTATOOR GlU 



oup. 73 



Chapter Yl.—Oofatoor Group.— Ootatoor Beds. 

 The Ootatoor Group is the lowest of the three nicain sub-divisions corn- 

 Extent of Grou prised in the great fossiHferous series of Trichinopoly 

 above the plant-beds. It occupies a strip of country 

 about 30 miles in length, and 3 or 4 miles in average width, in the talooks 

 of Tripatoor and Perambaloor, and extends in a North-east direction from 

 the neighbourhood of the Tehsildaree station* of Tripatoor, to within a 

 few miles of the Yellaur, where it is overlapped by the Arrialoor Group, 

 just before the entire series disappears beneath the great deposits of regur 

 and alluvium which occupy the valley of that river. Along the whole of 



. ,. , , . its western boundary it rests with undisturbed 



btratigrapmcal relations. 



stratification either on the gneiss or on the plant- 

 beds and coral-reef limestone, but on the south, where it abuts against the 

 confines of the Granitic region of Thutchuncoorchy, it is cut off by a system 

 of little parallel faults (briefly alluded to in the foregoing section) and con- 

 cealed beneath the beds of the Trichinopoly Group. That it originally 

 Originally more ex- extended far to the Westward and Southward of its 



present limits seems very probable, when we regard 



the lithologic characters of the existing formation, and the evidences 



of extensive denudation afforded by the abundance of its debris in the 



conglomerates of the higher groups ; no traces of it have, however, been 



found anywhere to the Westward or Southward of its present area, and 



on the North-east, in the District of South A root, it is equally wanting. 



In lithologic character the Ootatoor beds present much variety. Fine 



silts, calcareous shales, and sandy clays frequently 

 Lithological characters. 



concretionary, and more or less tinted with ochre- 



ous matter, predominate throughout the group; and as far North as 



Garoodamangalum and Kauray, constitute almost the entire bulk of the 



* The chief village of the talook or sub-division in which the Tulook Rcvcaue Officer, tlio 

 Tehsildar, resides. 



K 



