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Characteristics and Formation Mechanism of the Geothermal Field in the North China Downfaulted Basin
Author(s) -
Moxiang Chen,
Jiyang Wang,
Ji' an Wang,
Xiao Deng,
Shuzhen Yang,
Liangping Xiong,
Juming Zhang
Publication year - 1990
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.1990.mp3003008.x
Subject(s) - geothermal gradient , geology , tectonics , crust , structural basin , sedimentary rock , geomorphology , sedimentary basin , geochemistry , mantle (geology) , petrology , basement , thermal conduction , geophysics , seismology , civil engineering , materials science , engineering , composite material
The geothermal field is mainly controlled by the regional tectonic framework characterized by alternations of uplifted and depressed basement, and exhibits a similar zoned distribution of temperatures. In the uplifted area the geothermal gradient (G) and terrestrial heat flow value(q) of the Cenozoic sedimentary cover are relatively high, with G = 3.5 − 5.0°C / 100 m and q = 63‐84 mW / m 2 ; whereas in the depressions they are relatively low, with G = 2.7−3.5°C / 100 m and q = 46‐59 mW / m 2 . In the whole region, Ḡ = 3.581°C / 100 m and q = 61.5± 13.4 nW/ m 2 , indicating a comparatively high geothermal background and the presence of local geothermal anomalies. A comparison of the results of mathematical simulation of the geothermal field with the measured values shows a good agreement between them. The geothermal difference between various tectonic units is caused chiefly by the lateral and vertical variation of thermal properties of shallow crustal rocks. This phenomenon can be regarded as the result of redistribution of relatively uniform heat flows from the deep crust in the surficial part of the crust in the process of their upward conduction.