Heat flow, heat production, thermal structure and its tectonic implication of the southern Tan-Lu Fault Zone, East–Central China
Heat flow, heat production, thermal structure and its tectonic implication of the southern Tan-Lu Fault Zone, East–Central China
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DOI：
10.1016/j.geothermics.2019.06.007
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发表时间：
2019-11
期刊：
影响因子：
3.9
通讯作者：
Yibo Wang;Shengbiao Hu;Zhuting Wang;G. Jiang;D. Hu;Kesong Zhang;P. Gao;Jie Hu;Tao Zhang
中科院分区：
文献类型：
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作者：
Yibo Wang;Shengbiao Hu;Zhuting Wang;G. Jiang;D. Hu;Kesong Zhang;P. Gao;Jie Hu;Tao Zhang
我们提供了新的热流和产热数据来约束郯庐断裂带（STLFZ）（东亚连续活动的深地壳断裂带）南部的岩石圈热结构，并利用这些热数据来推断 STLFZ 的热结构如何影响区域震源深度。我们报告了 5 个新的高质量热流测量结果，这些测量结果来自 5 个井场的温度-深度剖面，以及来自 STLFZ 沿线 5 个井的 13 个露头样品和 115 个干燥岩心样品的详细热导率测量结果。我们结合已发表的数据对这些新数据进行分析，得出沿 STLFZ 的热剖面图，并绘制沿 STLFZ 的 350°C 等温线，该等温线与记录的地震活动的最大深度密切相关。结果表明：（1）沿STLFZ的温度梯度从南部的22.2°C km–1增加到北部的34.8°C km–1； (2) STLFZ沿线热流值在44.0~75.4mW·m–2范围内，平均值为59.9±10.5mW·m–2； (3) 热流最高值位于鲁宗盆地，上地壳放射性产热极高，达15~20μWm-3，可能与当地矿体有关； (4) STLFZ浅层地震带底界与350℃等温线重合。
We present new heat flow and heat production data to constrain the lithospheric thermal structure along the southern Tan-Lu Fault Zone (STLFZ), a continuous active deep crustal fault zone in East Asia, and use these thermal data to infer how the thermal structure of the STLFZ influences regional focal depths. We report five new high-quality heat flow measurements derived from temperature–depth profiles at five well sites and detailed thermal conductivity measurements of 13 outcrop samples and 115 dry core samples from five wells along the STLFZ. We analyze these new data in combination with published data to derive a thermal profile along the STLFZ and map the 350 °C isotherm along the STLFZ, which correlates well with the maximum depth of recorded seismicity. The results indicate that: (1) the thermal gradient along the STLFZ increase from 22.2 °C km–1in the south to 34.8 °C km–1in the north; (2) heat flow values are in the 44.0–75.4 mW m–2range along the STLFZ, with a mean value of 59.9 ± 10.5 mW m–2; (3) the highest heat flow value is located in Lu-Zong Basin, with extremely high radioactive heat production of 15–20 μW m–3in the upper crust that may be related to local ore bodies; and (4) the bottom boundary of the shallow-earthquake seismic zone in the STLFZ coincides with the 350 °C isotherm.