Neoproterozoic SHRIMP U-Pb zircon ages of silica-rich Dokhan Volcanics in the North Eastern Desert, Egypt
Neoproterozoic SHRIMP U-Pb zircon ages of silica-rich Dokhan Volcanics in the North Eastern Desert, Egypt
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DOI：
10.1016/j.precamres.2010.06.019
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发表时间：
2010-10-01
影响因子：
3.8
通讯作者：
Murata, Mamoru
中科院分区：
文献类型：
--
作者：
Breitkreuz, Christoph;Eliwa, Hassan;Murata, Mamoru
新元古代火山 - 沉积层序的年代对于阿拉伯 - 努比亚地盾的许多地区来说仍然存在争议，包括埃及东北部的多汉火山岩。从埃及东北部沙漠获取了10个富硅熔结凝灰岩和两个次火山英安质岩体（被绘制为多汉火山岩）的新的锆石U - Pb SHRIMP年龄。结晶年龄范围在592±5到630±6百万年（埃迪卡拉纪早期）之间。显然，阿拉伯 - 努比亚地盾的晚期固结伴随着孤立火山中心和盆地系统的演化，这些演化在大约4000万年的时期内发生，在空间和时间上是独立的，并且可能处于不断变化的构造环境下。所获得的年龄数据以及之前发表的多汉火山岩的其他可靠年龄表明火山活动有两个主要阶段：630 - 623百万年和618 - 592百万年。五个样本含有继承锆石，年龄分别为669、715 - 746、847和1530百万年，这支持了埃及东北部沙漠地壳主要是新元古代新生地壳的模型。（C）2010爱思唯尔有限公司。保留所有权利。
Chronology of Neoproterozoic volcanosedimentary successions remains controversial for many regions of the Arabian-Nubian Shield, including the Dokhan Volcanics of NE Egypt. New U-Pb zircon SHRIMP ages have been obtained for 10 silica-rich ignimbrites and two subvolcanic dacitic bodies, mapped as Dokhan Volcanics, from the North Eastern Desert of Egypt. Crystallization ages range between 592 +/- 5 and 630 +/- 6 Ma (Early Ediacaran). Apparently, the late consolidation of the Arabian-Nubian Shield was accompanied by the evolution of isolated volcanic centres and basin systems which developed during a period of approx. 40 Ma, independently in space and time and probably under changing tectonic regimes. The obtained age data together with other previously published reliable ages for Dokhan Volcanics suggest two main pulses of volcanic activity: 630-623 Ma and 618-592 Ma. Five samples contain inherited zircons, with ages of 669, 715-746, 847 and 1530 Ma, supporting models that North Eastern Desert crust is mainly juvenile Neoproterozoic crust. (C) 2010 Elsevier B.V. All rights reserved.