CONTENTS. 



Page 



Art. 1. — On the Cretaceous and other Roch of the South Arcot 

 and TiiiCHiNOPOLY Districts, Madras, iiy Henry 

 F. Blanford, Geological Survey of India ... ... 1 



Prefatory Notice ... ... Page v. 



Page. 



Part I. Chap. I. General Summary of previous researches ... ... 1 



„ II. General Description of Country ... .,, ... IG 



Part II. § 1. Descriptive details — Trichinojjoly District. 



Chap. III. Trichinopoly District — Crystalline Rocks ... ... 27 



„ IV- „ ,, Plant Beds ... ... ... 39 



„ V. ,) ), Ootatoor Group, 



(a.) Coral Eeef Liiccstoue 52 

 ,, VI. ), t, Ootatoor Group, 



(b.) Ootatoor Beds ... 73 



,, VII. ,, „ Trichinopoly Group ... ... 107 



,, VIII. „ )> Arrialoor Group ... ... 125 



§ 2. Verdachellum and Pondicherry areas. 



Chap. IX. Verdachellum area — Arrialoor Group... ... ... 14-t 



„ X. Pondicherry area — Arrialoor and Valudayur Groups ... 161 



„ XL ('uddalore Sandstones ... ... ., ... 165 



,, XII. Soils and superficial deposits ... ... ... 180 



Part III, Economic Geology ... ... ... ... ... .,, 20O 



( Issued, June, 1862. ) 



Art. 2. — Oil the Geological structure of jjarts of the Districts of 

 Salem, Trichinopoly, Tanjore, and South Arcot, in 

 Madras Presidency, (being the area incUuled on Sheet 79 

 of the Indian Atlas). By William King, Junr., Esq., 

 and E.. Bruce Foote, Esq,., Geological Stirvey of India ... 223 



Prefatory Notice ... ... Pf^ge v. 



JPage. 



Chap. I. Introductory — Genei'al description of area ... ... 223 



„ II. Alluvium— Blown Sands ... ... ... ... 247 



,, III. Post-cretaceous rocks ... ... ... ... 256 



„ IV. Metamorphic rocks ... ... ,,. ... 269 



1. Gneissose rocks — 



(a.) Varieties of gneiss ... ... ... 269 



(6) Crystalline Limestone ... ... 272 



(c.) Magnetic Iron Beds ... ... 279 



- (<^.) Granitoid gneiss ... ... 298 



2. Magnesite veins and deposits ... .,. 312 

 „ V. Crystalline rocks ... ... ... ... ... 328 



(rt.) Trap dykes ... ... ... ih. 



(b.) Granite; quartz veins ... ... 335 



„ VI, Superficial deposits and soils ... ... ... 342 



„ VII. Changes of surface now in progress... ... ..- 362 



„ VIII. Economic Geology... ... ... ... ... 367 



Appendix. On the Iron ores of Kunjamullay, near Salem ... 379 



(^Issued, June, 1864.) 



Art. 3. — The Coal of Assam; results of a drief visit to the Coal- 

 piELDS of that Province in 1865 j tvith Geological notes 

 071 Assam and the hills to the^soiith of it, hy H. B. 

 Medlicott, a. b., p. g. s.. Deputy Superintendent, Geolo- 

 gical Survey of India ... ... ... ... ... 387 



(_ Issued, July, 1865.) 



