Zircon U-Pb geochronology and elemental and Sr–Nd isotope geochemistry of Permian mafic rocks in the Funing area, SW China

被引：23

作者：

Mei-Fu Zhou

Jun-Hong Zhao

Liang Qi

Wenchao Su

Ruizhong Hu

机构：

[1] Chinese Academy of Sciences,Institute of Geochemistry

[2] University of Hong Kong,Department of Earth Sciences

来源：

Contributions to Mineralogy and Petrology | 2006年 / 151卷

关键词：

Volcanic Rock; Inductively Couple Plasma Mass Spectrometry; Mantle Source; Mantle Plume; Mafic Rock;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Mafic-layered intrusions and sills and spatially associated andesitic basalts are well preserved in the Funing area, SW China. The 258±3 Ma-layered intrusions are composed of fine-grained gabbro, gabbro and diorite. The 260±3 Ma sills consist of undifferentiated diabases. Both the layered intrusions and volcanic rocks belong to a low-Ti group, whereas the diabases belong to a high-Ti group. Rocks of the high-Ti group have FeO, TiO2 and P2O5 higher but MgO and Th/Nb ratios lower than those of the low-Ti group. They have initial 87Sr/86Sr ratios (0.706–0.707) lower and ɛNd (−1.5 to −0.6) higher than the low-Ti equivalents (0.710–0.715 and −9.6 to −4.0, respectively). The high-Ti group was formed from relatively primitive, high-Ti magmas generated by low degrees (7.3 –9.5%) of partial melting of an enriched, OIB-type asthenospheric mantle source. The low-Ti group may have formed from melts derived from an EM2-like, lithospheric mantle source. The mafic rocks at Funing are part of the Emeishan large igneous province formed by a mantle plume at ∼260 Ma.

引用

页码：1 / 19

页数：18

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