RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 4, NO. 3, PAGES 225–231, doi:10.2205/2002ES000091, 2002

Gamma ray spectrometry of rocks from a volcanic sequence penetrated by the SG-1 borehole and the radiogenic contribution to the total heat flow

Institute of Geology, National Academy of Sciences of Azerbaijan,, Azerbaijan

Abstract

[1]  Results derived from gamma-ray spectrometry studies of volcanic rocks in a depth interval of 3540-8150 m are presented. The rocks are shown to have low concentrations of radioactive elements, which is consistent with the clarke of basic igneous rocks close to calc-alkalic series of present island-arc systems. Potassium is present in all rocks of the volcanic sequence, whereas uranium and thorium are absent in some of its beds. Maximum U and Th concentrations are 410^-4 % and 610^-4 %, respectively. The Mesozoic sequence was subdivided into seven groups in accordance with associations of radioactive elements. The distribution of radioactive elements and their associations along the SG-1 section can be accepted as criteria for the differentiation of the volcanic sequence. Estimates of the radiogenic heat generation calculated for rocks of the volcanic sequence point to a considerable contribution of the radiogenic heat to the total heat flow. No proportionality exists between the radiogenic heat generation in the crust and measured heat flow.

Received 11 June 2002; published 25 June 2002.

Keywords: Gamma ray, spectrometry of rocks, total heat flow.

Copyright 2002 by the Russian Journal of Earth Sciences