On the timing and duration of the destruction of the North China Craton
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预定和北方中国 Craton 的破坏的持续时间，它对理解控制因素的破坏机制和它的 geodynamic 枢轴，仍然保持争论。根据岩浆开始和进化的原则，首先，我们构画出能与 cratonic 破坏有关的 magmatic 表情，然后，抑制时间的使用 magmatic 和盆进化趋势石版印刷可伸缩在诺思中国的球的变瘦。主要结论包括：(1 ) 在北方中国 Craton 下面岩石圈变瘦可能开始了，至少局部地，后来迟了含碳迟了三叠纪，在晚侏罗记早的白垩纪期间达到了它的高潮，并且继续到结束为止近来白垩纪早的新生代。北方中国 Craton 的破坏是一相对慢，而非一个戏剧的过程。(2 ) 沿着 craton 的边缘和内部的球的地区玩了的削弱的石版印刷在 cratonic 破坏的一个重要角色，部分为 cratonic 的异构的模式的财务破坏。(3 ) 控制了北方中国 Craton 的破坏的构造因素可能是多重的。在诺思中国和华南之间的 Paleo 亚洲的板和晚三叠纪的碰撞的晚含碳的向南方的 subduction 可能由影响 craton 的热、不可分的结构重新激活 craton。在东方亚洲大陆下面的和平的 subduction 在 cratonic 破坏起了一个决定因素作用，管理中生代以后的盆和主要构造配置的分发模式， magmatism 的时间的变化和纵贯的严肃貌的形成。Cite
The North China Craton (NCC) was originally formed by the amalgamation of the eastern and western blocks along an orogenic belt at ∼1.9 Ga. After cratonization, the NCC was essentially stable until the Mesozoic, when intense felsic magmatism and related mineralization, deformation, pull-apart basins, and exhumation of the deep crust widely occurred, indicative of destruction or decratonization. Accompanying this destruction was significant removal of the cratonic keel and lithospheric transformation, whereby the thick (∼200 km) and refractory Archean lithosphere mantle was replaced by a thin (<80 km) juvenile one. The decratonization of the NCC was driven by flat slab subduction, followed by a rollback of the paleo-Pacific plate during the late Mesozoic. A global synthesis indicates that cratons are mainly destroyed by oceanic subduction, although mantle plumes might also trigger lithospheric thinning through thermal erosion. Widespread crust-derived felsic magmatism and large-scale ductile deformation can be regarded as petrological and structural indicators of craton destruction. ▪ A craton, a kind of ancient continental block on Earth, was formed mostly in the early Precambrian (>1.8 Ga). ▪ A craton is characterized by a rigid lithospheric root, which provides longevity and stability during its evolutionary history. ▪ Some cratons, such as the North China Craton, can be destroyed by losing their stability, manifested by magmatism, deformation, earthquake, etc.
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Delamination
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U-Pb single-zircon analyses provide direct evidence for an enlarged early Archean craton forming the core to the present Zimbabwe craton. Virtually identical dates from the south-central Tokwe segment (3455 ± 2 Ma) and Midlands (3456 ± 6 Ma) parts of the craton strongly suggest their synchronous formation, during an event that formed a single early cratonic nucleus which we propose to call the “Sebakwe protocraton.” This is considered to underlie most of the current Zimbabwe craton. Parts of the craton are at least 3565 ± 21 Ma, a rock age reported here that represents the oldest rock dated from Zimbabwe. A ca. 3350 Ma relatively undeformed and unmetamorphosed intrusive granitic phase constrains the timing of the high-grade metamorphism and the stabilization of the protocraton. Comparison with published Re-Os data for the Zimbabwe craton strongly indicates a depleted subcontinental lithospheric mantle underlying the entire Sebakwe protocraton. Subsequent intrusive and volcanic activity from 3.0 to 2.6 Ga represents a second major period of magma genesis and crustal formation within which the predominant rocks of the exposed Zimbabwe craton were generated.
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几何学并且北方中国 craton (NCC ) 的合并预定是争论的与有地区性的结构的显著地不同的解释的三个主要模型一起，地球年代学，和地质的关系。赵 G C 等的模型。建议 NCC 的东方、西方的块独立形成了在太古代，并且活跃边缘在在 2.5 和 1.85 Ga 之间的东方块上被开发，二什么时候堵住，在蘸 subduction 的东方上面碰撞了地区。Kusky 等的模型。想从在大约 2.7 Ga 的一个未知更大的大陆的东方块 rifted ，并且与一条弧经历了碰撞(也许属于西方的块)在在 2.5 Ga 的一个蘸西方的 subduction 地区上面，并且当 NCC 加入了哥伦比亚 supercontinent 时， 1.85 Ga 变态与沿着 craton 的北边缘的碰撞有关。福莱等的模型。在中央 orogenic 带建议二碰撞，在 2.1 和 1.88 Ga。最近的地震结果两个都支持 Kusky 等的模型。并且福莱等，在中央 orogenic 带(圆块) 下面显示出那 subduction 是指导西方的，并且有一秒，定位到蘸在西方的块(Ordos craton ) 下面的圆块的东方的蘸西方的 paleosubduction 地区。通过地球物理识别的边界不与在赵等建议的 Trans 北方中国 orogen 的边界相关。模型，和 subduction 极性在由那个模型预言了那对面。地震侧面与在在 Kusky 等的模型预言的 COB 下面的一个蘸西方的 subduction 地区上面的太古代的碰撞一致，并且第二个蘸西方的 subduction 地区与二个事件在福莱等建议了一致。当模特儿。
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Continental Margin
Passive margin
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Devonian is a critical period for reversal of arc polarity and transition of continental margins from passive to active settings in the northern margin of the North China Block (NCB). However, the evolution processes during this period are still poorly constrained due to limited distributions of Devonian magmatism and sedimentary records in the NCB. In this paper, we present new zircon U–Pb geochronological, whole‐rock geochemical and Sr–Nd–Hf isotopic data of some recently identified Devonian volcanic rocks from the Jiefangyingzi area in the northeastern margin of the NCB. The Jiefangyingzi volcanic rocks display a bimodal composition and consist predominantly of amphibolite (meta‐basaltic andesite) and meta‐rhyolite and rhyolitic tuff with minor meta‐andesite. New SHRIMP and LA‐ICP‐MS zircon U–Pb dating results show that the volcanic rocks erupted during the early‐middle Devonian period (397–389 Ma). Geochemical and Sr–Nd–Hf isotopic data indicate that the mafic‐intermediate components were mainly derived from an enriched lithospheric mantle source, and the parental magma experienced fractional crystallization during magma ascent. The felsic rocks were mainly originated by partial melting of ancient lower continental crust, with mixing of some mantle‐derived mafic magmas. The occurrence of Devonian bimodal volcanic rocks, combined with the Devonian alkaline magmatic belt, suggesting that the northern margin of the NCB was a post‐collisional extension environment during the early‐middle Devonian period. In addition, the Sr–Nd–Hf isotopic results of the Devonian felsic volcanic rocks suggest that the Jiefangyingzi area is located in the North China Craton (NCC) rather than the Bainaimiao arc belt, and the orogen‐craton boundary between the northern NCC and Central Asian Orogenic Belt (CAOB) is located in some areas north to the Jiefangyingzi area.
Felsic
Devonian
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Yilgarn Craton
Detritus
Back-arc basin
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