BORE-HOLE INVESTIGATIONS 1095 



examples of radioactivity logging in a bore hole are found before 1909. 

 One of these is the study of the Balfour Bore, in Fifeshire, England. f In 

 this log, it is highly probable that the report is a measurement of radium, 

 the only substance for which there was a good means of measurement at 

 that time. Interesting questions are raised about these measurements 

 because of the low values reported for black shales, which are quite con- 

 trary to expectation. Another early well log was prepared by Ambronn, 

 who measured the natural radioactivity of well samples by a radiation 

 method. $ This log is unusual, in that it suggests a correlation between 

 radioactivity and the occurrence of petroleum, a finding which is not sup- 

 ported by more general experience on interpretation of these logs. 



Considerable added confusion, was created in this subject by a publica- 

 tion by Hurinuzescu,§ showing high activity of Romanian oils, Vingershoets 

 and Maurerff,!! have done the subject no good by their fantastically exag- 

 gerated claims regarding relationship between petroleum and radioactivity. 

 At the present it may be said with the utmost assurance that there is no 

 generally applicable principle of correlation between petroleum and radio- 

 activity. 



A very interesting early log is the one based on radium measurements, 

 m the St. Gothard Tunnel through the Alps, before 1909. In this case, 

 an efifort§§ was made to correlate the occurrence of high temperatures with 

 the high values of radium concentration. The earliest published gamma-ray 

 well-log made by a continuous profiling method appeared in 1939.ttt Other 

 workers were very active at the same time, and it was not long until 

 several more experimental papers were published.Ht The development of 

 gamma-ray well-logging followed very rapidly. An extensive bibliography 

 of these developments is to be found in the literature.§§§ 



Neutron well-logging began in 1938, and was the subject of a patent 

 application by Fearon.fttf The public was first informed of the discovery 

 of neutron well-logging in an article by B. Pontecorvo.$||| The first devel- 

 oped form of the neutron log was not very successful economically, because 



\ t' l°l^' "Radioactivity and Geology," p. 80, Constable, London, 1909. 



ihrerVetwerTu'ng,-' S%"s:Voi:''rNo%^^ "'' '"'"'^' '^"'^'=^^" Bodenschatze und 



I Hunnuzescu, A.. "Radium," Paris, 7, 231-2, 1910 (126) 

 Wien, 34,"538!m1'a2^6^ ' "^^'*''=^"''t <^" intern," Vereins der Bohringenieure und Bohrtechniker. 

 34, 3711^192^(126)"^^''^''''"^' ''" intern," Vereins der Bohringenieure und Bohrtechniker, Wien, 



II J. Joly "Radioactivity and Geology," Plate IV, Constable, London, 1909. 

 March, ml pp 10T144" F>-osch, "Gamma-Ray Well Logging," Geophysics, Vol. IV, No. 2, 



Feb* 22^'l'940^''''^'^''^'^*'°^ ^""^ ^' "' '^^^^*''>'' "^^^" Logging by Radioactivity," Oil and Gas Journal, 

 W- G- Green and R. E. Fearon, "Well Logging by Radioactivity," Geophysics, Vol. V, p. 272, 

 §§§ R. E^ Fearon "Radioactivity Well Logging," Oil Weekly, 118, 1945, pp. 33-41. 

 126-137221^239^' Paneth, "Radioactivity," Lawson Translation, Oxford, London, 1938, pp. 



Blackwood, et al, "Atomic Physics," Wiley and Sons, 1937, pp. 235-240. 



r/ Rutherford, "Radiations from Radioactive Substances," Cambridge, 1930 op 1-37. 

 xxii M-,r ,,^^'^"*^ 2,349,225, May 16, 1944, and 2,361,389, Oct. 31, 1944. 

 IIII ^ V " LjgS'ng Method and Apparatus," U. S. Patent 2,308,361, Tan. 12, 1943. 

 tit? Otl and Gas Journal, Sept. 11, 1941. 



