当前位置：
X-MOL 学术
›
Geolog. J.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Age, depositional environment, and tectonic significance of an Early Neoproterozoic volcano‐sedimentary sequence in the eastern Beishan orogenic belt, southern Central Asian Orogenic Belt
Geological Journal ( IF 1.4 ) Pub Date : 2020-09-28 , DOI: 10.1002/gj.3985 Biren Wang 1, 2 , Xiaosong Yang 1 , Shucai Li 2 , Chao Teng 2 , Xinjie Yang 2 , Fuyong Huang 2 , Jun Cao 2 , Bing Yang 2 , Xiaofei Zhang 3 , Yi Zhou 2
Geological Journal ( IF 1.4 ) Pub Date : 2020-09-28 , DOI: 10.1002/gj.3985 Biren Wang 1, 2 , Xiaosong Yang 1 , Shucai Li 2 , Chao Teng 2 , Xinjie Yang 2 , Fuyong Huang 2 , Jun Cao 2 , Bing Yang 2 , Xiaofei Zhang 3 , Yi Zhou 2
Affiliation
|
The Beishan orogenic belt, located in the southern Central Asian Orogenic Belt, includes several discrete arc terranes. Here, we report on a newly discovered Early Neoproterozoic volcano‐sedimentary sequence in the eastern Beishan orogenic belt in order to constrain the composition and origin of the Shuangyingshan‐Huaniushan Terrane. The ~766‐m‐thick volcano‐sedimentary sequence is very low‐grade metamorphosed, and characterized by muddy and silty slate with the well‐developed parallel laminations and minor thinly‐bedded limestone in its lower and upper sections, and thick packages of sandstone‐conglomerate and basaltic rocks in the middle section. Lava flow units in the basalt are very common, and the sandstone‐conglomerate exhibits sedimentary structures typical of gravity currents, including erosional and slump features, and Bouma sequences. These features suggest that syn‐sedimentary volcanism occurred and the sequence formed in an active, deep marine environment. The basalt has a zircon U–Pb age of 901 ± 10 Ma, indicating that this sequence formed during the Early Neoproterozoic. Basalt samples have moderate SiO2 (45.33–49.18%), and high TiO2 (1.27–4.04%) contents, Mg# values of 25–48, and plot in the alkali basalt field in the Nb/Y versus Zr/TiO2 diagram, indicative of an evolved alkali basalt magma. They show inclined chondrite‐normalized REE patterns with (La/Yb)N ratios of 4.74–6.53, no pronounced negative Eu anomalies (Eu/Eu* = 0.87–1.22), no obvious negative Zr, Hf, Nb, and Ta anomalies in the primitive‐mantle‐normalized trace‐element diagram, consistent with oceanic island basalts. Considered together, these lithologies resemble those of an oceanic seamount. Our results, and the presence of the previously reported Gubaoquan granitic and mafic rocks (905–865 Ma) that formed in an active continental margin setting and underwent an amphibolite‐facies metamorphism, suggest that the Shuangyingshan‐Huaniushan Terrane may be an accreted terrane that consists of different lithologies with various origins that formed during the Neoproterozoic.
中文翻译：
北山东部造山带，中亚南部造山带南部新元古代早期火山-沉积序列的年龄，沉积环境及其构造意义
位于中亚南部造山带南部的北山造山带包括几个离散的弧形地层。在这里，我们报道了北山东部造山带中新发现的新元古代早期火山-沉积序列，目的是限制双鹰山-焕牛山地貌的组成和成因。约766米厚的火山沉积序列变质程度很低，其特征是泥岩和粉质板岩，下部和上部发育良好的平行叠片和少量薄层灰岩，以及厚厚的砂岩包裹中段有砾岩和玄武岩。玄武岩中的熔岩流动单元非常普遍，而砂岩-砾岩则表现出典型的重力流沉积结构，包括侵蚀和坍落特征以及Bouma层序。这些特征表明，在沉积活跃的深海环境中发生了沉积沉积的火山作用，并形成了层序。玄武岩的锆石U–Pb年龄为901±10 Ma，表明该序列在新元古代早期形成。玄武岩样品具有中等SiO2（45.33–49.18％）和高TiO 2（1.27–4.04％）含量，Mg ＃值为25–48，并在Nb / Y与Zr / TiO 2图中的碱性玄武岩场中作图。演化成碱性玄武岩岩浆。它们显示倾斜的球粒陨石归一化REE模式，（La / Yb）N比值4.74–6.53，没有明显的负Eu异常（Eu / Eu * = 0.87–1.22），在原始地幔归一化痕量元素图中没有明显的负Zr，Hf，Nb和Ta异常，与大洋洲一致玄武岩。综合考虑，这些岩性类似于海洋海山。我们的结果以及先前报道的古宝泉花岗质和镁铁质岩（905-865 Ma）的存在是在活跃的大陆边缘环境中形成的，并经历了闪石岩相的变质作用，这表明双营山-焕牛山地体可能是一种增生的地体。由在新元古代形成的具有不同起源的不同岩性组成。
更新日期：2020-09-28
中文翻译：
北山东部造山带，中亚南部造山带南部新元古代早期火山-沉积序列的年龄，沉积环境及其构造意义
位于中亚南部造山带南部的北山造山带包括几个离散的弧形地层。在这里，我们报道了北山东部造山带中新发现的新元古代早期火山-沉积序列，目的是限制双鹰山-焕牛山地貌的组成和成因。约766米厚的火山沉积序列变质程度很低，其特征是泥岩和粉质板岩，下部和上部发育良好的平行叠片和少量薄层灰岩，以及厚厚的砂岩包裹中段有砾岩和玄武岩。玄武岩中的熔岩流动单元非常普遍，而砂岩-砾岩则表现出典型的重力流沉积结构，包括侵蚀和坍落特征以及Bouma层序。这些特征表明，在沉积活跃的深海环境中发生了沉积沉积的火山作用，并形成了层序。玄武岩的锆石U–Pb年龄为901±10 Ma，表明该序列在新元古代早期形成。玄武岩样品具有中等SiO2（45.33–49.18％）和高TiO 2（1.27–4.04％）含量，Mg ＃值为25–48，并在Nb / Y与Zr / TiO 2图中的碱性玄武岩场中作图。演化成碱性玄武岩岩浆。它们显示倾斜的球粒陨石归一化REE模式，（La / Yb）N比值4.74–6.53，没有明显的负Eu异常（Eu / Eu * = 0.87–1.22），在原始地幔归一化痕量元素图中没有明显的负Zr，Hf，Nb和Ta异常，与大洋洲一致玄武岩。综合考虑，这些岩性类似于海洋海山。我们的结果以及先前报道的古宝泉花岗质和镁铁质岩（905-865 Ma）的存在是在活跃的大陆边缘环境中形成的，并经历了闪石岩相的变质作用，这表明双营山-焕牛山地体可能是一种增生的地体。由在新元古代形成的具有不同起源的不同岩性组成。
京公网安备 11010802027423号