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| Titel |
Abnormal high surface heat flow caused by the Emeishan mantle plume |
| VerfasserIn |
Qiang Jiang, Nansheng Qiu, Chuanqing Zhu |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130692
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| Publikation (Nr.) |
 EGU/EGU2016-10987.pdf |
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| Zusammenfassung |
| It is commonly believed that increase of heat flow caused by a mantle plume is small and
transient. Seafloor heat flow data near the Hawaiian hotspot and the Iceland are comparable to
that for oceanic lithosphere elsewhere. Numerical modeling of the thermal effect of the
Parana large igneous province shows that the added heat flow at the surface caused
by the magmatic underplating is less than 5mW/m2. However, the thermal effect
of Emeishan mantle plume (EMP) may cause the surface hear-flow abnormally
high.
The Middle-Late Emeishan mantle plume is located in the western Yangtze Craton. The
Sichuan basin, to the northeast of the EMP, is a superimposed basin composed of Paleozoic
marine carbonate rocks and Mesozoic-Cenozoic terrestrial clastic rocks. The vitrinite
reflectance (Ro) data as a paleogeothermal indicator records an apparent change of thermal
regime of the Sichuan basin. The Ro profiles from boreholes and outcrops which are close
to the center of the basalt province exhibit a ‘dog-leg’ style at the unconformity
between the Middle and Upper Permian, and they show significantly higher gradients
in the lower subsection (pre-Middle Permian) than the Upper subsection (Upper
Permian to Mesozoic). Thermal history inversion based on these Ro data shows that
the lower subsection experienced a heat flow peak much higher than that of the
upper subsection. The abnormal heat flow in the Sichuan basin is consistent with
the EMP in temporal and spatial distribution. The high-temperature magmas from
deep mantle brought heat to the base of the lithosphere, and then large amount
of heat was conducted upwards, resulting in the abnormal high surface heat flow. |
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