656 
DESCRIPTION OF THE MAPS IN VOL. I. 
observed by Colonel Helmersen quite independently of ourselves. (See p. 53 et seq.) 
In 1842 (our general classification having been pointed out in memoirs read before the 
Geological Society of London) the Map was engraved and coloured accordingly in the 
form which it now T possesses, and with a table of organic remains to a great extent the 
same as that now appended to it. If the map had even then been published, all the 
main features of classification would have been sufficiently sustained for general objects ; 
but w'e naturally withheld it until we had reviewed and more thoroughly examined our 
organic remains, and had so extended our researches as to produce the present w r oik. 
Points of great importance have thus been added, the chief ot which consist in the new 
features of the Southern Ural, the insertion of the correct physical geography of the 
Ural Chain, the geographical and geological outlines of Scandinavia, and of various ame- 
liorations along the Polish and Carpathian frontiers ; some of which we derived from our 
owm explorations continued to 1844. Other changes and improvements have successively 
taken place, particularly in reference to great regions surrounding the area ot our personal 
survey. For these we necessarily consulted the map of V on Dechen for the German 
frontier, and the new map of Zeuschner for the Carpathians. Turkey is chiefly coloured 
from Boufi 1 ; the Caucasus is entirely taken from Dubois de Montpereux ; and the coun- 
tries south of the Black Sea from the researches of Mr. W. J. Hamilton and Mr. W. 
Ainsworth ; whilst the desert tracts between the Caspian and the Aral have undergone 
ameliorations through the critical inquiry of Colonel Helmersen into the observations of 
Basinier and other travellers. In regard to geographical features, the newest and most 
recent are those introduced from the Russian surveys of the South Ural and of all the 
wild regions extending therefrom to the Ubt-Urt and the Caspian and Aral Seas. These 
are chiefly derived from maps scarcely yet published and prepared by the brothers Khani- 
> We must here request geologists to understand, that as the portion of the Map representing South 
Hungary, Transylvania and Turkey is coloured to a small extent only from our personal knowledge, it is 
necessarily imperfect. Concerning a central portion of that region, we are, indeed, indebted for some 
corrections to our friend Mr. Warrington Smyth ; hut we beg unequivocally to state, that we are by no 
means certain whether portions of the crystalline rocks of these countries, which are coloured by us as 
metamorphic, may not be of azoic age ; whilst some of the granites may also be of azoic age, and not 
as we have inserted them, of date posterior to the paleozoic deposits. At the same time, whether our 
method of parallelizing the Turkish crystalline masses be right or wrong, we are certain from personal 
inspection of the Carpathians, that the Tatra granitic rocks have been erupted long posterior to the 
palaeozoic deposits, and are therefore wholly distinct in a geological sense from the azoic rocks of Scan- 
dinavia. They have indeed been evolved since the deposit of a sandstone which lies beneath the Liassic and 
Jurassic deposits, and have in some cases even protruded over these formations. Believing, in fact, that 
the Carpathians have been uplieaved and mineralized in a manner very analogous to the Alps, we have 
(judging from their relations) assigned to all the granitic rocks between them and the shores of Greece, 
a like modern age ; and on our general map we have not attempted to separate them from other eruptive 
rocks, even from those which are posterior to tertiary deposits. 
