Geology of part of Asia Minor, 597 



recent proofs of igneous agency on this side of the mountain. On the south- 

 ern flank I also observed, near the base, as I had before observed on the north- 

 ern flank, several traces of streams of black basalt, which had flowed into the 

 plain from near the foot of the mountain, and appear to have been partly 

 buried by the gradual increase of soil brought down from the different moun- 

 tains, and which, as there still appears to be no outlet for the waters, has a 

 slow but gradual tendency to fill up and raise the level of the plain. 



In concluding these remarks, I must express my regret, that the barrenness 

 of the subject is increased by the general absence of organic remains from the 

 great sedimentary formations of these tracts, and the consequent impossibility 

 of referring the deposits to those of Europe, or to fix even an approximate 

 scale of contemporaneity between them. In the red sandstone, I have never 

 found the slightest trace of fossils, and but rarely in the white calcareous beds. 

 In the neighbourhood of Sevri-hissar, W.S.W. of Angora, I discovered some 

 beds which were near the top of this calcareous series, and were full of 

 Limneae and Planorbes, whence I conclude that it is a freshwater lacustrine 

 formation. 



Although the region offers evidence of volcanic action at many different 

 periods, yet the igneous rocks are so rarely associated with stratified deposits, 

 that it is almost impossible to ascertain, with any degree of precision, the 

 geological era during which these events may have taken place. Nevertheless, 

 we can clearly distinguish two widely separated groups of stratified rocks, and 

 we have evidence of great volcanic activity between the two periods of their 

 accumulation. The first or lower is the red sandstone, which is always con- 

 nected with the salt districts of Asia Minor, and may, by analogy, be consi- 

 dered to be a secondary formation ; and the second or upper is the horizontal 

 white limestone, which, notwithstanding the violent convulsions to which most 

 parts of this country have been exposed at various periods, has, with scarcely 

 one exception, never been removed from its horizon tality, and may be consi- 

 dered as a tertiary formation. 



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