YENANGYOUNG. 103 



To prove these postulates absolutely a much larger number of 

 borings would be required ; as may be seen from the map, at most 

 places the lines are purely conjectural, and frequently the crucial 

 points are wanting in order to complete a given section. However, 

 there is still sufficient information contained in the boring registers 

 to strongly support my theory. 



A most favourable part is the northern end of the oil tract, 

 although there are unfortunately some four or five wells the boring 

 records of which are missing although they would be of the utmost 

 importance. 



As shown on the map the rich well No. 47 is surrounded on all 

 sides by a series of indifferent wells Nos. 11, 19, 20, 21,6 and 10 ; and 

 these again are surrounded by an irregular circle of poor wells Nos. 

 66, 64, 2, A, 5. The theory therefore requires that the petrolifer- 

 ous bed of No. 47 should represent the highest point, and that from 

 thence it should slope in every direction, excepting of course that 

 which forms the continuation of the central ridge. 



These borings are numerous enough to allow of three sections 

 being constructed; one in south-south-east and north-north-west direc- 

 tion, in fact, it is almost along a north to south line connecting wells 

 Nos. 1 1, 47, 21. The second in an east and west direction, connecting 

 wells Nos. 64(a) 20, 47, 10, and thence proceeding further towards 

 wells Nos. 8, 7 and 9. The third in a south-west to north-eastern 

 direction, connecting wells Nos. 19, 47, 6, A, and 36. 

 (a) Section XX, pi. XIII, wells Nos. 11, 47, 21. 

 The section in well No. 1 1 affords a very curious instance of 

 a large development of argillaceous beds ; after 75 feet of strata 

 belonging to the Yenangyoung stage, there follow 221 feet of 

 argillaceous beds, below which the petroliferous sand, to the thick- 

 ness of 97 feet, was found resting on Water bearing sand. The top 

 of the oil-sand was therefore 170 feet above sea level. 



In well No. 47 the section differs already considerably ; instead 

 of a compact bed of clay, as in No. 11, the argillaceous beds are 

 separated by a sandy bed of 25 feet thickness containing water-at 



( '49 ) 



