386 W. F, Hume — JVoies on Russian Geology. 



The heights of the principal localities may be easily correlated 

 ■with the level of the Chalk beneath the surface : — 



Chalk 78 ft. below surface. 

 Chalk 147-199 ft. below surface. 

 Not reached at 454 ft. (Phosphorite layeronlyreached). 

 Chalk reached at 132-9 ft. 

 Not reached at 529 ft. (Phosphorite layer). 

 (See Plate XI. Fig. 2). 



It will be evident by mere inspection that the following general 

 points may be observed in Fig. 1 and 2 : first, that the Tertiary 

 beds are divisible into two main divisions (I) an Upper, more sandy 

 division ; (2) a Lower, more clayey division ; second, that the Clialk 

 sti'ata are divisible into three main lithological divisions (1) a pure 

 ■white Chalk, in the main soft; (2) a more marly Chalk ; (3) a firm, 

 hard Chalk. Finally there is at the base a greensand, as in 

 England, followed by a few grey clays and sands. 



Secondly, it will be seen that the thickness of the Chalk strata 

 at Kharkoff alone almost doubles that in the London and Paris 

 Basins. 



A closer analysis of the Kharkoff bore yields the following details 

 of structure (the 133 feet of Tertiary beds are not at present dis- 

 cussed) : 



Feet in. 



Grey firm Chalk (more clayey) 

 White Chalk 

 Ditto soft 



Ditto hard (with glauconite) 

 Green sandy clay 

 Grey sand 

 Hard bound grey sand 



After these follow green and grey 



sands, alternating with dark sandy clays. 



At a depth of 2107ft. Sin. below the 



surface fossil wood was met with in a 



coarse grey sand. 



In the Soumy bore there is less detail (Tertiary beds here 200 feet thick). 

 Very soft white Chalk ... ... ... ... ... 216 feet 6 inches. 



3 ft. 6 in. firm bed between. 

 Ditto (light bluish) 143 feet. 



Then follow a series of alternations of hard and soft Chalk beds, 

 to a depth of 954 feet. At 898 feet there is a very hard bed with 

 bluish sandy balls, and at a depth of about 900 feet dark flints 

 make their appearance in a hard Chalk bed. Below this hard bed 

 (50 feet thick) commences the Chalk Marl, the latter being over 

 150 feet thick when the boring ceased. In the Glushkovo bore 

 (excluding 78 feet of Tertiary and later beds) 105 feet of clean soft 

 white Chalk -were passed through befoi'e the boring was finished. 



Although the want of fossils is marked, and the outcrops are few 

 and far between, it may yet be possible to obtain a few details as to 

 the faunal characters of the beds. For this purpose I undertook 

 a journey to Bielgorod, 75 versts to the N. of Kharkoff, visiting as 

 many quarries as it was possible during the time at my disposal. 



