1869.] CLARK INDIAN BASALT DYKES. 163 



Mr. David Foebes remarked that the existence of this leaf-bed 

 would formerly have been regarded as affording grounds for belief 

 in the non-igneous origin of basalt. He had, however, made ex- 

 periments as to the non-conducting-power of clay, and had found 

 that even half an inch of clay was sufficient to protect vegetable 

 forms from destruction by the heat of a mass of slag allowed to 

 flow over them. In the same manner he had found the forms of 

 leaves still preserved under the lava of Vesuvius and other active 

 volcanoes. 



Mr. R, H. Scott called attention to the work of Dr. Heer on the 

 specimens brought home from Greenland by Mr. Whymper, among 

 which he had recognized the fruits of various plants which had 

 already been identified by him from the leaves. The connexion 

 between these beds and those of Bovey Tracey, Oeningen, and other 

 Miocene deposits throughout Europe was now proved ; and the col- 

 lections just brought home from Spitzbergen by the Swedish Polar 

 Expedition would throw further light on the subject. No doubt 

 further discoveries would also be made of a similar character in the 

 north of Ireland. He pointed out the similarity between the Irish 

 section and those of Greenland, where vegetable remains were also 

 found interstratified with basalt. 



3. E-EMAEKS upon the Basalt Dykes of the Mainland o/India opposite 

 to the Islands of Bombay and Salsette. By George T. Claek, 

 Esq., F.G.S. 



The following remarks are the result of observations made during 

 the years 1845-6-7 upon the trap rocks of a part of the Bombay 

 Presidency. They were laid aside as being, at that time, of no great 

 interest in England, and are slightly alluded to in a letter from the 

 writer to Dean Buckland, not intended for publication, but which 

 was printed in the Quarterly Journal of the Geological Society for 

 January, 1847 [vol. iii. p. 221]. 



The paper now offered to the Society was written in that year. 

 Some recent remarks by Mr. A. B. Wynne upon the letter to Dr. 

 Buckland induce the writer now to bring it forward. Whatever value 

 it may possess is derived chiefly from the fact that it relates to a 

 district but little known, geologically, and which, from the difficul- 

 ties of climate and other local circumstances, is less accessible than 

 might be expected from its easy distance from Bombay. 



The physical features of Western India are very peculiar. The 

 surface of the peninsula rises very gradually from the Bay of Bengal 

 to an irregular line ranging north and south from twenty to fifty 

 miles from the western coast. At this line the ground, there very 

 high, terminates in an escarpment of from 100 to 1000 feet in depth, 

 and more or less precipitous. The strip of land intervening between 

 this escarpment and the western sea, though of irregidar surface, 

 and containing several lofty spurs from the high ground, and some 

 detached ridges, is on the whole not very much above the sea-level. 



VOL. XXV. — part I. n 



