42 GEOLOGICAL MEMOIRS. 



zontal beds of extraordinary extent and thickness. They were elevated 

 by the same forces which have cansed the many regularly-formed 

 conical hills, crowning the tops of those remarkable table-lands for an 

 extent of fifty-four geographical (German) miles, at longer or shorter 

 intervals, and which contribute so much to the landscape charms of 

 the Armenian highlands. With this peculiar natural condition of 

 closely connected volcanic table-lands, apparently universally repeated 

 in the more western mountain districts of Asia Minor, are connected 

 certain conditions of climate and of a physical character, which have 

 exercised a considerable influence on the habits and development of 

 the people of these regions. 



The liability to decomposition of these volcanic crystalline rocks, 

 which, like doierite and trachyte, produce such a favourable soil for 

 the vegetation of grasses and cerealia, acting on these table-lands, which 

 for the most part are above the limits of the growth of trees in these 

 regions (which in the Lower Caucasus may be reckoned at from 7000 

 to 7800 French feet), has principally called into existence those 

 boundless alpine meadows, on which the existence of the Nomadic 

 tribes of Asia Minor mainly depends. Whilst the horizontality of the 

 connected uplands favours the equal distribution and collection of the 

 snows of winter, the porous nature of the rock itself is the principal 

 cause, that on this substratum a much smaller proportion of the 

 melted waters returns by evaporation into the atmosphere, than is the 

 case on steeper mountain heights, consisting of a more compact rock, 

 and having either none or only a very thin covering of soil. Hence 

 the production and origin of those numerous and peculiar sources to 

 which the name of Karasu waters has been applied* ; and this term 

 has so far the merit of physical distinction, as by it all springs rising 

 in lofty uplands, elevated by volcanic action, can be distinguished from 

 such as rise out of other formations. Everywhere do these Karasu 

 springs rise with an astonishing abundance of water, partly at the 

 edges of the volcanic table-lands, even at the greatest heights, and 

 partly im-mediately amidst and belov/ the beds of lava which stretch 

 down from the mountains into the open valleys. 



The great reservoir of the Goktschai lake, 5500 feet above the sea, 

 and covering a surface of 1 126 square wersts, which at diiferent periods 

 of the year exerts such a favourable influence on the climate of the 

 neighbourhood, and particularly on the meteorological state of the 

 plain of the Araxes, is almost solely maintained by the powerful streams 

 which flow into it from the volcanic heights which in an unbroken 

 line shut it in on the south and on the west. The Sanga would be an 

 inconsiderable stream, were it not for the numerous Karasu rivers 

 which it receives in its long course of 100 wersts, issuing from the 

 lavas which have extended to the N.W. in enormous coulees from 



* The word Karasu signifies black water, and is a term universally given 

 throughout Asia Minor to a deep-flowing river in a mountainous district. I can- 

 not quite adopt Prof. Abich's theory, as I have met with rivers called by that 

 name in many parts of Asia Minor, where the nature of the country and the rocks 

 preclude the idea of the term being derived from any cause like that alluded to in 

 the text. Several rivers of this name are mentioned in my work on Asia Minor.— 

 W. J. H. 



