ARAVALLI— ARYAN. 19 



than some of the Dharwars. This view is adopted by L. L. 

 Fermor (Mem., Geol. Surv., hid,, XXXVII, 236, 1909), and 

 is substantially similar to that finally adopted by J. D. Dana 

 himself in the 4th Edition of his Text-Book published in 1875, 

 where he includes gneisses of all kinds and infolded metamor- 

 phosed elastics. Van Hise also afterwards adopted this meaning 

 for the Archaean, including, with the gneissose granites and 

 schists, the iron-bearing formations of Vermilion, Marquette, 

 etc. (21st Ann. Kept., U. S. Geol. Surv., Part III, 19.01, 305 

 — 434). E. Vredenburg (Summary of the Geol. of India, 

 Calcutta, 1907, p. 4) restricts the term in a novel way to rocks 

 " underlying the oldest imdoubted sediments " among which 

 are gneisses representing " in part, at least, the original crust 

 of the globe, when the surface of the originally molten mass 

 first began to solidify." He thus excludes the Dharwars, but 

 includes the Khondalites of Walker, which are altered sedi- 

 ments, with the Hosur gneissose granite which is young enough 

 to have picked up fragments of the Dharwars. 



Archipelago series Name applied by R. D. Oldham (Rec, Geol. 



Surv., Ind,, XVIII, 138, 1885) to rocks occurring in the 

 Ritchie Archipelago and mainland of the Andamans. Shown 

 by G. H. Tipper (Mem,, Geol. Surv., Ind,, XXXV, 5, 7, 1910) to 

 be composite in character. 



Ariyalur Stage. — A stage in the Cretaceous deposits of the Trichi- 

 nopoly, Viruddhachalam, and Pondicherry areas distinguished by 

 H. F. Blanford (Mem., Geol. Surv., Ind., IV, 23, 125, 1862). 

 Age, about Upper Senonian ; divided in the Pondicherry area 

 into a lower horizon known as the Anisoceras, or Valudayur, 

 beds, and an upper, distinguished as the Trigonoarca beds 

 (F. Kossmat, Rec, Geol. Surv., Ind,, XXX, 58, 67, 81 and 

 82, 1897) . The Ninniyur beds of Danian age were formerly 

 regarded as part of the Ariyalur stage and form part of a 

 continuous series of beds. Ariyalur, from a village in the Trichi- 

 nopoly district (11° 8'; 79° 8'). E. Vredenburg (Rec, Geol. 

 Surv., Ind., XXXVI, 195, 211, 1908) correlates the Ariyalur 

 with the Hemipneustes beds of Baluchistan, which he regards 

 as Campanian in the lower part (Valudayur beds; and Maestrichtian 

 above (Trigonoarca beds). 



Aryan group and era.— Name proposed by T. H. Holland (Trans, 

 Min. Geol. Inst., Ind., I, 49, 1906 ; Imperial Gazetteer of India, 



Q % 



