THERMAL CONDUCTIVITIES OF ROCKS 263 



Recent geothermal surveys show that relatively high temperatures are 

 generally associated with faults, salt domes, sand lenses, and anticlinal 

 structures of both large and small closure. 



Radioactivity and thermal condition through oil-bearing strata are shown 

 to be possible sources of temperature variations. 



Generation of heat by the oxidation of petroleum appears to be of minor 

 importance as a heat source. The most potent source of heat is to be found 

 in the hot rocks immediately beneath uplifts. 



Temperature Measurements in Boreholes in the Vicinity of Hamburg. 



By E. Koch. 

 Mitteilungen aus dem Mineralogisch-Geologischen Staatsinstitut in Hamburg, 



vol. 14, 1933, PP- 53-8o. 



Thirty-two temperature measurements made in the boreholes in the 

 vicinity of Hamburg are described in detail. From the results of measure- 

 ments the geothermal gradient for this region was calculated to be 29 to 

 39 metres, or a mean value of 34 metres per i° C. 



Smaller values (down to 18-93) were found in the region of an oil-bearing 

 salt dome ; higher values (up to 65 ■ 24) were explained by the effect caused 

 by ground waters. The temperature measurements in the Lieth borehole 

 near Elmshom from 1872 to 1878 are discussed. 



Geothermal Measurements in Artesian Boreholes in Kharkov and 

 moscow during the summer of 1932. 



By S. Kraskowski. 

 Beitrdge zur angewandten Geophysik, Leipzig, vol. 4, no. 1, 1933, pp. 76-87. 



In the summer of 1932 the author made a number of geothermal observa- 

 tions in the artesian wells in Kharkov and in Moscow. The purpose of the 

 measurements in Kharkov was to investigate the distribution of the tempera- 

 ture in boreholes which penetrated the whole series of Cretaceous layers, 

 the depth of the latter reaching about 550 metres. At the same time, it 

 was desirable to know to what extent the course of the temperature curve 

 was affected by the structural changes in the layers. 



The measurements in Moscow were made in one borehole in the yard of 

 the Institute of Geology and Mineralogy and in the borehole of the city 

 slaughterhouse. 



From the temperatures obtained it was possible to calculate the geo- 

 thermal gradient for Moscow and to establish the influence of the tubes 

 inserted in the holes upon the distribution of the temperature. 



The difference of the temperature readings in the holes with tubes and 

 without them did not exceed ±0-2° C. ; that is, the limits of the mean 

 error for ordinary temperature measurements were not surpassed. 



Contribution to the History of the Geothermal Gradient. 



By H. Geiler. 



Gesch. d. Math., d. Naturwiss. und d. Techn., vol. 13, 1931, pp. 352-358. 



A historical outline and explanations of the earth's heat are given based 

 on the study of publications by Kayser, Koenigsberger, Sieberg and others. 

 Factors influencing the geothermal gradient are assembled. 



