758 



Notes and Correspondence. 



[Oct., 



of the rocks for some distance. 

 The valley, however, terminates 

 some distance beyond the last well, 

 and the limestone conceals the oil- 

 bearing beds for another two miles, 

 after which there are strong sulphur 

 springs in a cross valley between 

 the valley of Beshevli and the coast 

 range of limestone. Beyond this 

 are the waters of the sea of Azof. 



Another remarkable and interest- 

 ing petroleum spring is within a few 

 miles of the town of Kertch, to the 

 south-west ; and here also the geo- 

 logical conditions are both curious 

 and instructive. In a valley running 

 westwards into the country, but not 

 opening from the sea, enclosed be- 

 tween hills capped with limestone, 

 one of which is very celebrated in 

 ancient history as the tomb of Mir 

 thridates, there is seen a conical 

 hill with a large crater open on the 

 side towards the north, and on ap- 

 proaching the hill the opening is 

 seen to resemble another valley, and 

 to contain other much smaller cones 

 of various size, some extremely per- 

 fect, and one perhaps 50 yards in 

 circumference at the base. Close to 

 the base of this cone, to the west, 

 a well has been sunk in rotten clays 

 and shales, sandstones, and nodular 

 masses of iron, all dipping about 

 70° to north. In this well oil was 

 reached at 17 feet, at a bed overlying 

 the nodular ironstone. From 17 feet 

 to 60 feet there was always some 

 oil, and at 60 feet a band of sand- 

 stone was cut through. This rock 

 was saturated with bitumen, and 

 below it petroleum came into the 

 well with great rapidity. Three feet 

 lower the ground was so soft and 

 tough as to rise up and render any 

 further sinking impossible with the 

 means at hand. A bore was then put 

 down, and the oil stood at 6^ feet 

 above the bottom of the bore at the 

 time of my visit, and was replaced 

 very rapidly when removed. The 

 naphtha raised was of excellent qua- 

 lity, and remarkably clear and pure. 

 There was no water whatever in the 

 well or boring. 



The ground where this well was 



sunk is about 100 feet above the 

 level of the Black Sea, measured by a 

 good mountain aneroid. About 50 

 yards to the south is an active mud 

 volcano, and several small cones re- 

 sulting from the eruption of mud 

 are to be seen in an east and west 

 line from this point. Some of them 

 are at a considerable distance, and 

 besides them sulphur springs ap- 

 pear both to the east and south. 

 A very few yards beyond the line 

 of the mud volcanoes to the south 

 several borings have been made, 

 but no trace of petroleum has been 

 found. 



Other borings nearer the well 

 have shown a trace of oil, and a 

 strong bituminous odour was found 

 to characterize all the strata, but 

 no sinkings have been successful 

 that have not reached the sandstone. 

 There can be no doubt that the 

 source of supply of oil in this case 

 is limited to the line of strike of a 

 certain stratum, and it is more than 

 probable that here, as at Beshevli, 

 there is a reversion of strata and 

 an anticlinal axis close by. At this 

 point, however, I was unable to ob- 

 tain proof of the axis by independent 

 observation, for though the lime- 

 stone capping the shales dips to the 

 south, the shales are quite inde- 

 pendent of these limestones. The 

 existence of the line of mud volcanoes 

 is however sufficient to justify the 

 assumption that there is a fault or 

 fissure communicating with the seat 

 of chemical changes and operations 

 in the interior of the earth. 



A remarkable instance of petro- 

 leum springs is to be found on the 

 shores of a salt lake some ten miles 

 to the south of Kertch, close to the 

 line of coast. The lake is large but 

 shallow, and its level is a few feet be- 

 low that of the Black Sea. It is called 

 ' Tchongolek.' It is separated from 

 the sea by a low bank of shelly sand 

 a few feet above the highest level 

 of the Black Sea, so that there is at 

 no time free communication between 

 the two waters, and the level of the 

 lake is permanently below that of 

 the adjacent open sea by at least 



