Geochronology and C-O-Sr-Nd isotopic study of the Ulgii Khiid carbonatite from the Southern Mongolian alkaline Province and its implications for the mantle sources
Geochronology and C-O-Sr-Nd isotopic study of the Ulgii Khiid carbonatite from the Southern Mongolian alkaline Province and its implications for the mantle sources
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南蒙古碱性省乌列盖碳酸岩年代学、C-O-Sr-Nd同位素研究及其对地幔来源的意义
DOI：
10.1016/j.oregeorev.2021.104495
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发表时间：
2021-12
影响因子：
3.3
通讯作者：
Fang Guicong
中科院分区：
文献类型：
--
作者：
Feng Meng;Song Wenlei;Kynicky Jindrich;Feng Boxin;Fang Guicong
乌尔吉希伊德碳酸盐-碱性岩杂岩体位于中亚蒙古南部著名的碱性省。然而，该杂岩的成因缺乏约束，其构造环境仍然存在争议（即，地幔柱与俯冲相关的碰撞后）。本文报道了磷灰石U-Pb测年、常量和微量元素以及C-O-Sr-Nd同位素数据，以制约碳酸盐岩和相关碱性正长岩的起源和地幔来源。磷灰石的年龄为166 ± 25 Ma，与碱性正长岩的年龄一致。碳酸盐岩具有较高的P2 O 5、Sr和REE含量，而较低的碱和HFSE（Nb、Ta、Zr和Hf）含量。碳酸盐岩和碱性正长岩的Sr [（87 Sr/86 Sr）i：0.7041-0.7049和0.7044-0.7048]和Nd [εNd（t）：4.1-4.8和4.2-4.7]同位素组成具有局限性和相似性，表明它们具有共同的地幔源区。结合前人的熔融包裹体资料，认为乌尔吉Khiid碳酸岩是由碳酸盐-硅酸盐液态不渗透作用形成的。碳酸岩的δ 13 CVPD和δ 18 OVSMOW值分别为-2.6 ‰ ~-9.4 ‰和10.6 ‰ ~ 23.2‰，表明地幔与沉积碳酸盐岩具有正的碳氧线性相关，表明俯冲的沉积碳酸盐岩已并入地幔源区。因此，我们建议，乌尔吉Khiid，和其他碳酸盐岩复杂的碱性省的蒙古南部，通过低程度熔融的底层碳酸盐岩石圈地幔，这是不均匀的俯冲古亚洲洋修改。
The Ulgii Khiid carbonatite-alkaline rock complex is located within the well-known Alkaline Province of Southern Mongolia, Central Asia. However, the complex's origin is poorly constrained, and its tectonic environment remains controversial (i.e., mantle plume vs. subduction-related post-collision). Here, we report apatite U-Pb dating, major and trace elements, and C-O-Sr-Nd isotopic data to constrain the origin and mantle source of the carbonatite and associated alkaline syenite rocks. The apatites yield an age of 166 ± 25 Ma, coeval to the related alkaline syenite's age reported previously. The carbonatite show higher P2O5, Sr, and REE but lower alkalis and HFSE (Nb, Ta, Zr, and Hf) contents. The carbonatite and alkaline syenite show restricted and similar Sr [(87Sr/86Sr)i: 0.7041–0.7049 and 0.7044–0.7048] and Nd [εNd(t): 4.1–4.8 and 4.2–4.7, respectively] isotopic compositions, indicating a common mantle source. Combined with the previous melt inclusion data, it is, therefore, suggested that the Ulgii Khiid carbonatite was formed by carbonate–silicate liquid immiscibility from a carbonated mantle source. The δ13CVPDBand δ18OVSMOWvalues of the carbonatites vary from −2.6 to −9.4‰ and 10.6 to 23.2‰, respectively and show a positive C-O linear correlation between the mantle and sedimentary carbonates, which imply the incorporation of the subducted sedimentary carbonates into the mantle source. We, therefore, propose that the Ulgii Khiid, and other carbonatite complexes in the Alkaline Province of Southern Mongolia, were produced via low-degree melting of the underlying carbonated lithospheric mantle, which is heterogeneously modified by the subducted Paleo-Asian Ocean.
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影响因子：
0.9
作者：
R. H. Mitchell
通讯作者：
R. H. Mitchell
影响因子：
3.9
作者：
K. Bell
通讯作者：
K. Bell
DOI：
10.4236/ijg.2013.48114
发表时间：
2013-10
期刊：
International Journal of Geosciences
影响因子：
--
作者：
Munkhtsengel Baatar;G. Ochir;J. Kynický;S. Iizumi;P. Comin-Chiaramonti
通讯作者：
Munkhtsengel Baatar;G. Ochir;J. Kynický;S. Iizumi;P. Comin-Chiaramonti
影响因子：
13.6
作者：
Amsellem, Elsa;Moynier, Frederic;Day, James M. D.
通讯作者：
Day, James M. D.
影响因子：
3.9
作者：
Okay Çimen;C. Kuebler;S. Simonetti;Loretta Corcoran;R. Mitchell;A. Simonetti
通讯作者：
Okay Çimen;C. Kuebler;S. Simonetti;Loretta Corcoran;R. Mitchell;A. Simonetti