10 FOOTE ; GEOLOGY OF MADURA AND TINNEVELLY DISTRICTS. 



Caldwell's paper described the triangular area enclosed between straight 

 lines drawn east and south from Nang-imeri to the sea. I have 

 unfortunately been unable to obtain a copy of this paper, so can 

 only speak of it from memory after reading- it many years since. His 

 paper was accompanied by a sketch map of the country described, on 

 which most of the leading features are laid down very truthfully. 



Some interesting observations on the nature and the rate of move- 

 ment of the teris or red blown sands as dis- 

 tinguished from the white or pale sands of the 

 coast dunes were made and published by Lieutenant- Colonel B. B,. 

 Branfill, Deputy Superintendent, Trigonometrical Survey. 



Some further information of important character ^ on the rate of 

 movement of the teri sands were given by Lieutenant-Colonel B. B. 

 Branfill in the general report of the Great Trigonometrical Survey for 

 1873-74, which will be referred to at length when describing those 

 remarkable seolian formations. 



A few geological notes are given in the District Manual of Tinnevelly 

 by Mr. A. Gr. Stuart, C.S., but they are too brief to convey much 

 information.^ 



CHAPTEB III. 



THE GNEISSIC ROCKS. 



The relations of the various great band of crystalline rocks, which are 

 met with over the tract of country lying westward of the belt of 

 sedimentary rocks lying along the sea-board 'of Madura and Tinnevelly 

 districts, have not yet been worked out fully, nor can they be even 

 approximately settled till the flanks and summits of the Southern Ghats 



^ Notes on the Tinnevelly District by Captaiu B. R. Branfill, Great Trigonometrical 

 Survey of India, Dclira Doon, 1869. 



An important note on the climate of South Tinnevelly by Dr. Caldwell forms au 

 appendix to Captain Branfill's pamphlet. 



2 A Manual of the Tinnevelly District, compiled by A. J. Stuart, M.C.S., Madras, 1879. 



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