part 4] ox the miocexe of ceylox. 583 



The areno-argillaceous series appears to rest unconformable 

 upon the limestones. It seems to be identical with a series 

 appearing along the coast east and north of Kudremalai Point and 

 extending almost to Arippu, which shows striking resemblances 

 with the areno-argillaceous rocks of Minihagalkanda. 



South of Kudremalai Point another series of sandy beds appears 

 in a cliff 40 feet high. Its relationship to the areno-argillaceous. 

 series is not clear : the latter may either be faulted or deposited 

 against it. In either case the sandy series is probably the older. 

 The succession shown is the following, the two lowest divisions 

 forming the main part of the 40-foot cliff : — 



5. Red earth. 



4. Fine-grained and very deep-red sandstone, denuded to a mass of 

 small pinnacles. 



3. Impure, somewhat nodular limestone, weathering into small dome- 

 like masses. 



2. False-bedded sandstone, with fossils (land-shells). 



1. Sandstone, dipping generally 30° east by south. 



A bed similar to No. 4 is seen in one of the inland sections, 

 between the red earth and the areno-argillaceous series. 



The fossils from the false-bedded sandstone were submitted to 

 Mr. Gr. K. Gude, who kindly reported on them as follows : — 



' I would withoxit hesitation say that they belong to the family Zonitidffi. 

 and am strongly inclined to refer them to the genus Ariophanta ( = Xestina) 

 many species of which are Ceylon natives. It is unfortunate that the 

 specimens are in rather poor condition, and specific determination, I am 

 afraid, is out of the question.' 



The only conclusion to be drawn from these fossils is that the 

 sandstone is Kainozoic. It is not likely to be Miocene, or at least 

 not Upper Miocene, since marine deposits of that date occur so 

 near ; but whether pre- or post-Miocene must remain uncertain. 



Sanely beds without fossils also appear along the coast, 

 between Ambalama and Karaitivu. 



White argillaceous beds, possibly Miocene, but unfossiliferous, 

 occur on the coast at Ambalama, and inland, beneath red earth, 

 at Iranamadu. 



Conclusion. 



To sum up, we know that at Minihagalkanda the local base of 

 the deposits which Dr. Davies has shown to be of Miocene age is 

 represented by inconstant areno-argillaceous beds with limestone 

 partings ; the Miocene of Jaffna, of which neither the base nor the 

 top is known, is essentialhy limestone ; in part of the Anurudhapura 

 district, limestone closely similar to that of Jaffna is succeeded b} r 

 beds remarkably like those of Kudremalai and the lowest Miocene 

 of Minihagalkanda. So it is possible that the Ceylon Miocene 

 represents a complete cycle of movement and deposition : that is 

 to say, depression followed by uplift, the two shallow-water phases 

 being represented by areno-argillaceous beds of no great thickness, 



<^. .I.G.S. No. 316. 2 r 



