82 CRETACEOUS ROCKS OF S. INDIA. [pART II. § 1. 



exhibit gaping cracks in every direction, resembling a half shattered piece of Mosaic work. 

 These cracks, unlike those of ordinary Septaria, are almost confined to the exterior, and 

 appear to be due to the crystallization of the cementing carbonates. Fragments of these 

 concretions closely resemble those of the " zig-zag" shales ; they occur both in the upper 

 part of the Ootatoor Group, around Sei-valuppoor and Alundanapuram, and in the Trichi- 

 nopoly beds, to the South-east of the latter place. 



Between Agaram and Paroovalapoor, unfossiliferous gypseous clays constitute almost the 

 entire mass of the Ootatoor beds. They are usually laminated, 



Beds S. E. of Agaram. ^^^ ^^ various colors, tints of yellow, grey, red, and olive-green, 



each predominating in turn. To the South-west of Agaram these are seen resting on the 

 gneiss without the intervention of any conglomerate or boulder-bed, but on their Southern 

 boundary a boulder-bed or mass of gneiss blocks extends for about half a mile along their base 

 between the Muddam outlier of the Trichinopoly beds and the nullah which drains the area 

 above described. 



Beyond this nullah but little of the Ootatoor beds is seen, the surface being evenly covered 



with cotton soil, except where the latter is cut through by one or 

 Beds North of Paroovalapoor. n , • -r • n .i, j j i x ^ xi, 



two little nullahs, m which the sands and conglomerates oi the 



Trichinopoly beds are for the most part the only beds exposed ; but on the boundary about a mile 

 to the North-west of Paroovalapoor some laminated clays or rather shales are exposed, which 

 have all the characters of the Ootatoor beds, and which are twisted 

 ^^ ' and broken in such a manner as to induce the belief that they 



are here faulted against the gneiss. Very little of them is, however, seen, and I could not satis- 

 factorily establish the existence of a fault. Similar beds, characterised as usual by intercalated 

 layers of Gypsum are seen also along the Northern edge of the Trichinopoly beds, and at one 



place I found a band of blue limestone containing a few fossils. 

 Dip of beds. ^ ° 



The dip of all these beds, except in the instance above noted, is 



very gentle, rarely exceeding 6° or 8°, and is generally towards the North-east or away from 

 the gneiss. 



In the country between Paroovalapoor and Ootatoor but little of the rocks is exposed, except 

 along the "Western boundary, where they rest on the gneiss or the plant-beds ; and at a few 

 points to the Eastward between Paroovalapoor and Servaluppoor, near the overlap of the Tri- 

 chinopoly Group. The former are soft brown argillaceous silts, with Gypsum and occasionally 

 ferruginous nodules, which appear to have been formerly collected and smelted for iron, 

 as lumps of old slags are not unfrequently met with in the vicinity. These beds are weU 

 seen between Agaram and Naicolum. They are quite imfossiliferous. The latter beds are 

 clays and yellow shales, also gypseous, with occasional bands of Kmestone, all equally 

 unfossiliferous. 



To the East of Ootatoor brown and ochi-eous clay or silt prevails almost to the exclusion of 

 Character of country East of other forms of rock. Looking Eastward from one of the gneiss 

 Ootatoor. mounds that front the village, the eye wanders for miles over a 



low, smooth, undulating tract, unbroken by tree, shi'ub, or rock, thinly covered with tufts of wiry 

 grass, and seamed here and there with broad muddy nullahs. Far to the Eastward the view is 

 bounded by a prominent ridge of limestone, hereafter to be described, which marks the base 

 of the Trichinopoly Group, while to the North, on the flank of the low ridge which forms the 

 watershed of the Mm-dayaui', a mass of low rounded mounds simulating as remarked by 



