Thermal conductivity of sediments in high-latitude West Siberia

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• 作者：A.D. Duchkov ; L.S. Sokolova ; D.E. Ayunov ; O.N. Zlobina
• 关键词：core samples from high-latitude boreholes ; thermal conductivity ; West Siberian Plate ; Yenisei&ndash ; Khatanga basin
• 刊名：Russian Geology and Geophysics
• 出版年：December, 2013
• 年：2013
• 卷：54
• 期：12
• 页码：1522-1528
• 全文大小：468 K

文摘

The thermal conductivity of rocks (位) used previously to estimate heat flow in high-latitude Siberia was assumed to be 位 = 1.8-2.0 W/(m鈰匥), according to published evidence, but was almost never measured specially. We measured the thermal conductivity of core samples from boreholes drilled in the northeastern West Siberian Plate and in the Yenisei-Khatanga basin in the 1990s, using two advanced instruments: a comparator and a scanner of thermal conductivity. Altogether there were 305 samples of air-dry sediments (位_d) from the 1100-4200 m interval of 23 holes, out of which 77 samples were then moistened (位_w). The average thermal conductivities of rocks in dry and wet conditions were found to be 位_d = 1.9 卤 0.2 and 位_w = 2.6 卤 0.1 W/(m鈰匥), respectively. Thus, the true thermal conductivity of sediments, which are saturated with water in this northern area, must be about 20-30% higher than that assumed in the previous heat flow determinations, and the latter are thus underestimated correspondingly. The updates to the thermal conductivity values imply major revision to the existing ideas of the thermal regime in the Siberian high latitudes. Such a serious revision of geothermal data will obviously require a large amount of additional experimental work.