760 Notes and Correspondence. [Oct., 



Fig. 3.— Section across part of the Shore of Lake Tchongolek. 



Scale of feet. 

 Vertical and Horizontal 



those that generally yield petro- 

 leum in the district. The dip of 

 the clays there are no means of 

 determining. 



On a continuance of the line of this 

 fault as marked by petroleum wells, 

 there are other wells at various 

 points to the west to a distance of 

 about two miles. The waters of 

 the lake also show bubbles of' gas 

 with petroleum rising at some dis- 

 tance from the shore, far beyond 

 the last well to the east. 



There are at least half-a-dozen 

 other distinct localities, within 30 

 miles of Kertch, in which naphtha 

 has been obtained by the Tatars in 

 old times, as shown by their lines 

 of wells, and also by modern sink- 

 ings, none of them very deep. All 

 are characterized in the same man- 

 ner. All occur in valleys, and the 

 strata through which the petroleum 

 rises are always highly inclined and 

 generally much disturbed. They 

 are always the marls and clays of 

 the lower series, over which the 

 limestones with few exceptions lie 

 unconformably. The direction of 

 the belts of ground yielding petro- 

 leum, of the principal lines of eleva- 

 tion of the district, and of the lines 



of direction of the mud volcanoes, 

 are aU approximately the same, and 

 there are springs of mineral water 

 that appear to have a similar 

 bearing. 



I think there can be no doubt 

 that throughout the whole petro- 

 leum district, extending from the 

 eastern shores of the Caspian Sea 

 to the Carpathians, a distance of 

 more than fifteen hundred miles 

 from east to west, there must be 

 similar causes at work to produce 

 effects so identical as those ob- 

 seved. At intervals, which, it is 

 true, are of considerable length, but 

 always in rocks of the same kind, 

 and of the same geological age, 

 always, that is, in clays and marl 

 of middle or older tertiary date, 

 there are certain bands or belts of 

 highly-inclined and fractured strata, 

 through which mineral waters, mud, 

 or petroleum occasionally issue. 

 These are all strictly connected 

 with the last great elevations to 

 which the lands of the pre- and post- 

 glacial epochs are due. All those 

 lands, whether actually then above 

 the water or only shoals rising 

 slowly to form the vast steppes and 

 plains of Asia and Europe, are due 



