492 



INDEX. 



Dorsetshire, greensand formation of, 9. 



, Hastings sand on the coast of, 11. 



, . — , Purbeck beds on the coast of, 11. 



., description of inferior oolite in, 30. 



, succession of changes in the coast of, 



45. 



Down Chff, notice of a conglomerate in the infe- 

 rior oolite, formed of fragments of that rock, 

 31. 



Duddon, notice of a fault in valley of the, 51. 



Dufrenoy, M., notice of his memoirs on the beds 

 below the chalk in the South-west of France, 

 330. 



Dukhun, portion of, described by Lieut. -Col. 

 Sykes, 409. 



_, , its boundaries, 409. 



, stratification of, 410. 



, the Ghats of, 411. 



, the valleys of, 412. 



, not produced 



by rivers, 413. 



— , terraces, 413. 



, escarpments of the Ghats in, 



described, 414. 



, columnar basalt a great geo- 

 logical feature in, 414. 



, basaltic and amygdaloidal 



columns in, 415. 



-, places of their occurrence. 



415, 416. 



-, schistose, indurated clay as- 



sociated with basalt, 417. 

 , basalt en boules (or nodular 



basalt) of, 417 ; its localities, ib. 

 , basaltic dykes of, 418 ; their 



localities, ib. 



, prismatic character of, 418. 



, ferruginous clay associated 



with basalt described, 419; its localities, ib. 

 , limestone, three forms of, 



Dukhun, portions of, limestone, specimen of com- 

 pact found by Colonel Sykes in, 421. 



— — ^— , loose basaltic stones occur 



in immense quantities, 421. 



, heaps of rocks and stones 



in the, 421. 



— i , occurrence of sheets of rock 



in the, 422 ; description of them, ib. ; their loca- 

 lities, ib. 



■■ — , structure and mineral com- 



position of the trap rocks of, 422. 

 , a variety of green compact 



basalt found in, 422 ; description of it, 423. 

 , prevalence of amygdaloids 



in certain localities in, 423. 

 , amygdaloid with vermicular 



stilbite, 424. 

 , minerals found In the trap 



rocks of, 424 ; their localities, 425. 

 , natural salts of, 425 ; their 



localities, 425, 426. 



, ores of, 42 G. 



, no organic remains met with 



by Colonel Sykes, 426. 

 , the absence of remarkable, 



427. 



gion in, 428. 



in, 428. 



429. 



-, great extent of the trap re- 



-, absence of volcanic products 



-, age of the trap formation of, 



-, laterite of, 430 ; its loca- 



, granite of, 431. 



, sedimentary rocks of, 431. 



: , mode of determination of 



the elevations of, 432. 

 , explanation of the sections 



lities, ib. 



419. 



its localities, 420. 



-, pulverulent, 419; 



accompanying Col. Sykes's paper on, 432. 

 Dunnose, in the Isle of Wight, its true position, 



191, note. 

 Dunscombe Hill, notice of pits in the chalk of, 

 filled with flints, 6. 



great abundance in certain localities, 420, 430. Dunstable, Bedfordshire, section through, 292. 

 , crystalline of, 421. Dunton, Bucks, quarries of Portland stone at,272. 



-, nodular, 420; its 



