Mid- to Late Cambrian docking of the Río de la Plata craton to southwestern Gondwana: age constraints from U–Pb SHRIMP detrital zircon ages from Sierras de Ambato and Velasco (Sierras Pampeanas, Argentina)
Mid- to Late Cambrian docking of the Río de la Plata craton to southwestern Gondwana: age constraints from U–Pb SHRIMP detrital zircon ages from Sierras de Ambato and Velasco (Sierras Pampeanas, Argentina)
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中晚寒武世拉普拉塔克拉通与冈瓦纳西南部的对接：来自安巴托山脉和贝拉斯科山脉（阿根廷潘皮纳斯山脉）的 U-Pb SHRIMP 碎屑锆石年龄的年龄限制
DOI：
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发表时间：
2011
影响因子：
2.7
通讯作者：
C. Galindo
中科院分区：
文献类型：
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作者：
S. Verdecchia;C. Casquet;E. Baldo;R. Pankhurst;C. Rapela;M. Fanning;C. Galindo
摘要：阿根廷中部东潘皮亚山脉早古生代地层和构造历史受潘皮亚纪（545-510 Ma）和法玛蒂纪（490-440 Ma）造山运动的变质作用和变形影响。本文报道了在Quebrada de La cacimbila （c. 28°45'S, 66°25'W）暴露的两个变质沉积层系：Ambato变质杂岩和La cacimicbila变质杂岩中，U-Pb敏感高分辨率离子探针的碎屑锆石定年。Ambato锆石记录的年龄峰值对应于Pampean（530±10 Ma）、Brasiliano（约570 ~约640 Ma）、Grenville（约950 ~约1025 Ma）和较小的新太古代。类似的峰值在La cacimbila样品中也很明显，但它还含有古元古代的锆石（约2.1 Ga），与bbb10 de La Plata克拉通的年龄相对应，它们被认为是来自于此。我们的解释是，安巴托杂岩的原岩沉积在克拉通并置之前，比早奥陶世的La cacimbila变质杂岩更古老。我们推断克拉通在中-晚寒武世形成其目前的相对位置，在Pampean主要构造热事件（530-520 Ma）之后，在La c<s:1> bila原岩和Achavil组（Sierra de Famatina）沉积之前，这两个组含有相当的碎屑锆石群。
Abstract: The Early Palaeozoic stratigraphy and tectonic history of the Eastern Sierras Pampeanas of central Argentina are complicated by metamorphism and deformation resulting from the Pampean (545–510 Ma) and Famatinian (490–440 Ma) orogenies. We report U–Pb sensitive high-resolution ion microprobe dating of detrital zircons in two metasedimentary successions exposed at Quebrada de La Cébila (c. 28°45'S, 66°25'W): the Ambato and the La Cébila metamorphic complexes. The Ambato zircons record age peaks corresponding to Pampean (530 ± 10 Ma), Brasiliano (c. 570 and c. 640 Ma), Grenville (c. 950 to c. 1025 Ma) and minor Neoarchaean ages. Similar peaks are also apparent in the La Cébila sample but it additionally contains Palaeoproterozoic zircons (c. 2.1 Ga) corresponding to the age of the Rio de la Plata craton, from which they are considered to have been sourced. Our interpretation is that the protolith of the Ambato complex was deposited prior to juxtaposition with the craton and is older than the Early Ordovician La Cébila metamorphic complex. We infer that the craton reached its current relative position in the Mid- to Late Cambrian, after the main Pampean tectonothermal event (530–520 Ma) and before deposition of the La Cébila protolith and the Achavil Formation (Sierra de Famatina), which contain comparable detrital zircon populations.
影响因子：
6.1
作者：
Adams, C. J.;Miller, H.;Griffin, W. L.
通讯作者：
Griffin, W. L.