apetl — SEPT. 1858. J Sandstones containing Fossil Wood. 47 



II. On the Geological age of the Sandstones containing 



Fossil Wood, at Trivicary, near Pondicherry, By H. F. 



Blanford, of the Geological Survey of India. 



The sandstones occurring at the village of Trivicary near Pondi- 

 cherry have long been known to Indian Geologists from their con- 

 taining in considerable quantity the silicified remains of the stems 

 of trees. These beds were first brought to public notice, by the late 

 Mr. Kaye, of the Madras Civil Service, in his paper on the Geology 

 of the Country around Pondicherry, published in Vol. Part of the 

 6th Transactions of the Geological Society of London. In the same 

 paper are also described certain other sandstones occurring at the 

 village of Verdoor Valudayur, four miles South East of Trivicary, 

 and a large series of fossils collected from these rocks, by Mr. 

 Kaye, and Mr. Brooke Cunliffe, were sent home and described, by 

 the late Professor Edward Forbes, in the admirable Monograph 

 which accompanies Mr. Kaye's paper. From these fossils Profes- 

 sor Forbes determined the Verdoor sandstones to be of cretaceous 

 age, and he stated his opinion that they were about coeval with the 

 lower cretaceous or Neocomian rocks of Europe. The age of the 

 Trivicary sandstones however still remained doubtful, and no de- 

 cided opinion was enunciated on the subject, until in the course of 

 last year, Mr. Adolphe Schlagentweit published in the Journal of 

 the Asiatic Society of Bengal,* his " Report on the Progress of 

 the Magnetic Survey, &c. from November 1855 to April 1856." 



In this Report Mr. Schlagentweit having described the great 

 series of sandstones and plant-bearing beds throughout Central 

 India and portions of Bengal, and assuming the Trivicary sand- 

 stones to be of the same age, says : — " With reference to the diffi- 

 cult question of the age of the sandstone formation, it is worth 

 mentioning that I have seen the sandstone with fossil trees clearly 

 overlaid by the cretaceous strata, the Pondicherry district, so that 

 it cannot be younger than Jurassic," and further on : — " The cre- 

 taceous strata seem to have been quite undisturbed ; they rest ho- 

 rizontally upon the oolitic sandstones of Trivicary, and upon the 

 crystalline schists in other localities," and as these sandstones coin- 



* No. II for 1857- 

 Vol. xx. o. s. Vol. iv. n, s. 



