Provenance of conglomerate clasts from the volcano-sedimentary sequence at Wadi Rutig in southern Sinai, Egypt as revealed by SIMS U–Pb dating of zircon
Provenance of conglomerate clasts from the volcano-sedimentary sequence at Wadi Rutig in southern Sinai, Egypt as revealed by SIMS U–Pb dating of zircon
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DOI：
10.1016/j.gr.2010.11.021
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发表时间：
2011-09
影响因子：
6.1
通讯作者：
M. D. Samuel;Y. Be'eri‐Shlevin;M. Azer;M. Whitehouse;H. E. Moussa
中科院分区：
文献类型：
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作者：
M. D. Samuel;Y. Be'eri‐Shlevin;M. Azer;M. Whitehouse;H. E. Moussa
位于阿拉伯努比亚地盾最北端的西奈Wadi Rutig的火山-沉积岩系包括早期埃迪卡拉火山岩与未成熟沉积物（包括大小不等的砾岩、砂岩和粉砂岩）互层。本文报道了新的西姆斯U-Pb年龄，它们分别来自于该系列中不同级别的砾岩和这些砾岩中的单个卵石。两个砾岩样品的年龄概率模式显示，600 - 860 Ma组分的贡献较大，640- 710 Ma组分的贡献较大，约600 - 710 Ma组分的贡献较小。900 - 1100 Ma组件。花岗岩和英安岩组成的单鹅卵石产生的年龄约。615 Ma和629 Ma。的物源模式是兼容的主要派生从已知的ANS年龄材料在西奈半岛（600- 850 Ma），但也表明，前870 Ma的组件占主导地位的最新中元古代最早新元古代更广泛的最北端的ANS比以前认识到。640- 710 Ma的年龄差距支持在这个时候在最北端的ANS，特别是在西奈半岛，这是在更南部的ANS段的演化形成鲜明对比的岩浆活动的平静。CA。Rutig砾岩中710- 740 Ma年龄的碎屑锆石被解释为反映了该年龄段的岩浆来源，迄今为止在最北端的ANS中没有发现。最年轻的碎屑锆石U-Pb年龄结合其他证据表明，砾岩的沉积可局限于约。620- 610 Ma和600- 590 Ma。两个侵蚀-沉积阶段的认识进行了讨论的背景下，不断变化的地球动力学背景下碰撞后崩溃的ANS造山带后约。630Ma。物源模式和盆地演化进行了比较，以其他晚新元古代火山沉积序列的最北端的ANS。
The volcano-sedimentary succession at Wadi Rutig, Sinai, at the northernmost segment of the Arabian Nubian Shield comprises early Ediacaran volcanic rocks interbedded with immature sediments including variable sized conglomerates, sandstones and siltstones. We report new SIMS U–Pb ages of zircons separated from conglomerates of various levels in the succession and from single cobbles of these conglomerates. The age probability patterns of two conglomerate samples reveal major contribution from 600 to 860Ma components with a prominent gap at 640–710Ma and some contribution from ca. 900 to 1100Ma components. Single cobbles of granitic and dacitic compositions yield ages of ca. 615Ma and 629Ma respectively. The provenance patterns are compatible with major derivation from known ANS age material in Sinai (600–850Ma), but also indicate that pre-870Ma components of dominantly latest Mesoproterozoic to earliest Neoproterozoic were more widespread in the northernmost ANS than previously appreciated. The 640–710Ma age gap supports a lull in magmatic activity at this time in the northernmost ANS especially in Sinai, which is in marked contrast with the evolution of more southerly ANS segments. The ca. 710–740Ma age detrital zircons in the Rutig conglomerates are interpreted to reflect magmatic source of this age range, hitherto not identified in the northernmost ANS. U–Pb ages of youngest detrital zircons combined with other evidence indicate that deposition of conglomerates can be confined to ca. 620–610Ma and 600–590Ma. The recognition of two erosion–deposition phases is discussed within the context of a changing geodynamic setting during post-collisional collapse of the ANS orogen after ca. 630Ma. Both provenance patterns and basin evolution are compared to other late Neoproterozoic volcano-sedimentary successions of the northernmost ANS.