1840.] 



of the Great Basaltic District of India. 



81 



being concealed by basaltic soil, mixed with calcedonies, fragments of 

 that rock, schist, and of a coarse puddingstone, which I did not find in 

 situ. The hill of Won is composed of sandstone, dipping in all directions 

 from the apet, and varying in colour from white to red and yellow. It 

 contains also feiruginous grains or scales, either in seams or disseminat- 

 ed through its substance. In a fragment of this kind much resembling 

 the cement of the Bangnapilly diamond breccia, a fossil was discovered 

 having a compact structure and deep black colour, and it is probably 

 a portion of a hollow, compressed vegetable, the centre of which is 

 filled with the sandstone. It is the only instance that has come to my 

 knowledge of a fossil being found in the sandstone of Southern India ; 

 and as the rock corresponds in geological position and mineralogical 

 characters with the diamond sandstone, the fact is of considerable interest, 

 even if the formations were not found to be continuous, as will be stated- 

 hereafter. The specimen is deposited in the Museum of the Asiatic 

 Society of Bengal. 



Sandstone, argillaceous limestone, and schist constitute the building- 

 stones of the surrounding country, which is much buried under basalt, 

 and a black alluvial soil containing calcedonies, jaspers, &c. A few 

 miles south of Chicknee,* (where the fossils were again met with,) the 

 red schist found above the limestone south of the Urjunah hot- springs 

 and in various places of the diamond districts of the south, reappears, 

 intermixed with protruding masses of basalt, which have altered it in 

 the most singular manner, — the lime of which it is in part composed, 

 being converted into a fine crystalline mineral, in which the red clay 

 is enveloped or diffused, giving the rock and even hand specimens a 

 very striking appearance. Near Chicknee, the schist rises slightly to- 

 wards a basaltic ridge, in which the fossiliferous chert is likewise imbed- 

 ded. The schist is divided into minute rhombs by vertical partings, in 

 which veins of calcareous spar from an eighth to half an inch thick have 

 been formed, and give it a beautiful, reticulated appearance. Lime is 

 ■found in the schist, and portions of the red clay are enveloped in the cry- 

 stalline limestone, which contains no magnesia. 



The fossils occur on the surface, or are imbedded in nodular basalt 

 over several miles, being found in blocks of indurated clay, chert, and 

 ■flinty slite. The appearance of the indurated clay is the same as in some 

 of the specimens from the Sichel Hills, but the clay is harder, full of 

 cavities, and in some cases passes into perfect chert, or has waved lines 

 of quartz or opalized matter diffused through the substance of the mass. 



♦ Fossils were first found at Chicknee bj^ Mr. W. Geddes, May, 18;J9. 



