| Abstrakt: |
The lithospheric thermal structure (LTS) not only reflects the thermal state of the Earth's interior but also controls the formation and distribution of geothermal resources. However, related research in the Songliao Basin (SB) has focused mainly on the northern or southern parts of the basin, with limited basin-scale thermal state studies. Thus, we combined published heat flow (HF) data and thermal parameters from the northern SB with new thermal information from the southern SB to study the LTS of the entire basin. The results show that the SB has a terrestrial HF (q0) of 73.89 ± 14.25 mW m−2, a temperature gradient of 41.41 ± 8.0 °C km−1, a mantle HF (qm) of 57.49 mW/m2, a crustal HF (qc) of 16.40 mW/m2, and a qm/q0 value of > 0.5, all of which indicate a typical configuration involving a hot mantle and a cold crust and high geothermal background in the SB. In addition, the thinned "thermal" lithospheric thickness in the SB is only 56.16 km. We correlate these characteristics with the westward subduction of the Pacific plate. From the proximal Kuril Trench to the distal Inner Mongolia Plateau in the subduction-influenced region, q0 generally decreases, qc increases, qm decreases, and the qm/q0 ratio gradually decreases. Thus, the present LTS in the SB might be controlled by the moderate distance of the SB from the subduction zone. Furthermore, in terms of geothermal resources in the SB, in addition to the high qm, which acts as the principal systematic heat source, deep hot partial melts act as direct heat sources and might also be controlled by the moderate distance from the subduction zone. Our results provide new insights into the relationship between the LTS and geothermal resources in similar regions. [ABSTRACT FROM AUTHOR] |
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