ARAVALLI SYSTEM. 41 



with allanite prominent, are about G inches to 1 foot thick, following 

 a rougli parallelism in the veins. 



3 V 5 2 (12147), is the calc-gneiss associated with the above. 

 Allanite has been discovered before in coarse pegmatites in India* 

 (see specimens found by Sir Thomas Holland and myself near 

 Andiguppanur, Salem district, Madras Presidency (see General 

 Report, Geological Survey of India, 1897—1898. p. 19). and analysed 

 later by Mr. F. R. Mallet, but only as isolated lumps). This is the 

 first instance, so far as I know, of it constituting almost the sole 

 ferro-magnesian mineral in a rock of medium grain, and not as a 

 mere accessory, with the exception perhaps of the Nellore pegmatite 

 described by Mr. Tipper, 1 which also contains samarskite. It is of 

 interest to note, however, that gadolinito. which often accompanies 

 allanite and other minerals of the rare earths in pegmatites, has 

 been recorded by Babu Baidyanath Sana in the neighbouring state 

 of Palanpur in a tourmaline pegmatite, together with distinct, large 

 crystals of cassiterite. 2 



It will have been noticed in the preceding descriptions of these 

 various aplites that micropegmatite and also coarse graphic struc- 

 ture in the quartz-felspar have seldom been referred to. Such 

 structure is more common where the accompanying dark minerals 

 disappear nearly or altogether, although even then it is not uni- 

 versal. At the following places, these more purely quartz-felspar 

 varieties have been observed, but the list is not exhaustive : the 

 858 ft. hill near Damavas ( 4 2 8 5 R ) near Medh (^) and ( 4 ? 8 3 6 ) being 

 the same locality as ££- 6 already described, p. 37, south of 

 Vivau and 3 miles N. by E. of Vadali ( 4 2 8 \) and from near Khedwa 

 (3V9) tne last ' being a beautiful, coarsely graphic granite with no 

 dark minerals. 



There does not seem to be much analogy between the aplites 

 - _ . °f Ida 1 State and the granites and pegmatites 



Other analogous vein r rn i • 3 i , , , .. ., « — ,. 



granite. of Chhmdwara lately described by L. L. 



Fermor in connection with his description of 

 the calc-gneiss and other associated rocks in the Central Provinces 

 (see footnote, p. 21). In Ceylon, however, the granites and 

 pegmatites of the Balangoda group described by A. K. Coomara- 



* It also occurs in largo quantity in a coarse pegmatite associated with megnotitc, 

 at Karadikuttam Pattiamhodikutru in Madras District. 



1 Bee, OeoL Surr. India. Vol. XU, pf. 2, p. 



* Misc. Note by T. H. Holland, in Bee, 0. 8, I., Vol., XXXT, pt. 1, p. r.\ (1904). 



