Geochemistry, geochronology and petrogenesis of Maya Block granitoids and dykes from the Chicxulub Impact Crater, Gulf of México: Implications for the assembly of Pangea
Geochemistry, geochronology and petrogenesis of Maya Block granitoids and dykes from the Chicxulub Impact Crater, Gulf of México: Implications for the assembly of Pangea
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墨西哥湾希克苏鲁伯撞击坑的玛雅块体花岗岩和岩脉的地球化学、地质年代学和岩石成因：对盘古大陆组装的影响
DOI：
10.1016/j.gr.2019.12.003
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发表时间：
2020-06
影响因子：
6.1
通讯作者：
Vivi Vajda
中科院分区：
文献类型：
--
作者：
Jiawei Zhao;Long Xiao;Sean P.S. Gulick;Joanna V. Morgan;David Kring;Jaime Urrutia Fucugauchi;Martin Schmieder;Sietze J. de Graaff;Axel Wittmann;Catherine H. Ross;Philippe Claeys;Annemarie Pickersgill;Pim Kaskes;Steven Goderis;Cornelia Rasmussen;Vivi Vajda
由于该地区缺乏同时代岩浆岩的出露，人们对玛雅地块晚古生代构造-岩浆史和基底的了解很少。最近，对国际大洋钻探项目-ICDP第364次考察队在梅西科尤卡坦半岛近海的希克苏鲁布撞击坑峰环的M0077 A钻孔回收的岩芯样品进行了全面研究。在最低~600米的岩芯中，撞击变形的花岗岩类和较小的长英岩和粗玄岩岩脉与撞击熔体和角砾岩互层。花岗岩类锆石U-Pb年龄为326 ± 5 Ma，代表晚古生代岩浆岩首次从玛雅地块中恢复，可能与古陆的劳伦提斯和冈瓦纳的会聚有关。花岗岩类具有高K2 O/Na 2 O、LaN/YbN和Sr/Y比值，而Yb和Y含量很低的特征，显示出埃达克质的亲合性。它们的Nd同位素（326 Ma）值为0.17-0.68，87 Sr/86 Sr（326 Ma）值为0.7036-0.7047，具有中等偏正的特征，两阶段Nd模式年龄（TDM 2）值为1027-1069 Ma，可能是一个演化程度较低的地壳源区。因此，埃达克质花岗岩类可能是由部分熔融增厚的地壳，源成分类似于新元古代变质辉长岩在卡罗莱纳块（泛非造山材料）沿着冈瓦纳大陆。长英岩脉为钾玄岩，具有典型的大陆弧特征，来源于板块流体交代地幔楔。白云岩脉具有Nb、Ta正异常和低ThNpm/NbNpm的OIB型特征。根据我们的解释，本研究中的希克苏鲁布埃达克质花岗岩类是由板片断裂引起的软流圈上涌引起的地壳深熔作用形成的。通过对比晚古生代岩浆活动沿着冈瓦纳域的来源和过程，一个撕裂板片断裂模式可以解释劳伦大陆和冈瓦纳大陆会聚期间出现的不连续岩浆活动。
The Late Paleozoic tectono–magmatic history and basement of the Maya block are poorly understood due to the lack of exposures of coeval magmatic rocks in the region. Recently, IODP–ICDP Expedition 364 recovered drill core samples at borehole M0077A from the peak ring of the Chicxulub impact crater, offshore of the Yucatán peninsula in the Gulf of México, have been studied comprehensively. In the lowermost ~600 m of the drill core, impact–deformed granitoids, and minor felsite and dolerite dykes are intercalated with impact melts and breccias. Zircon U-Pb dating of granitoids yielded ages of around 326 ± 5 Ma, representing the first recovery of Late Paleozoic magmatic rocks from the Maya block, which could be genetically related to the convergence of Laurentia and Gondwana. The granitoids show the features of high K2O/Na2O, LaN/YbNand Sr/Y ratios, but very low Yb and Y contents, indicating an adakitic affinity. They are also characterized by slightly positive ԑNd(326Ma)of 0.17–0.68, intermediate initial87Sr/86Sr(326Ma)of 0.7036–0.7047 and two–stage Nd model age (TDM2) of 1027–1069 Ma, which may indicate a less evolved crustal source. Thus, the adakitic granitoids were probably generated by partial melting of thickened crust, with source components similar to Neoproterozoic metagabbro in the Carolina block (Pan–African Orogeny materials) along Peri–Gondwana. Felsite dykes are shoshonitic with typical continental arc features that are sourced from a metasomatic mantle wedge by slab–fluids. Dolerite dykes display OIB–type features such as positive Nb and Ta anomalies and low ThNpm/NbNpm. In our interpretation, the Chicxulub adakitic granitoids of this study are formed by crustal anatexis due to asthenospheric upwelling resulting from slab breakoff. Through comparing sources and processes of Late Paleozoic magmatism along the Peri–Gondwanan realm, a tearing slab breakoff model may explain the discontinuous magmatism that appears to have occurred during the convergence of Laurentia and Gondwana.
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影响因子：
1.4
作者：
J. Keppie;R. D. Dallmeyer
通讯作者：
J. Keppie;R. D. Dallmeyer
影响因子：
2.6
作者：
J. Keppie;J. Dostal;M. Norman;J. Urrutia‐Fucugauchi;Manuel Grajales-Nishimura
通讯作者：
J. Keppie;J. Dostal;M. Norman;J. Urrutia‐Fucugauchi;Manuel Grajales-Nishimura
影响因子：
--
作者：
M. Steiner;J. Walker
通讯作者：
M. Steiner;J. Walker
DOI：
10.1130/0-8137-1191-6.287
发表时间：
1997
期刊：
Geological Society of America Memoirs
影响因子：
--
作者：
J. Speer;Kevin W. Hoff
通讯作者：
J. Speer;Kevin W. Hoff
影响因子：
5.8
作者：
P. Clift;P. Heinrich;D. Dunn;Andrew Jacobus;J. Blusztajn
通讯作者：
P. Clift;P. Heinrich;D. Dunn;Andrew Jacobus;J. Blusztajn