Revised radiolarian ages for the sedimentary cover of the Balagne ophiolite (Corsica, France). Implications for the palaeoenvironmental evolution of the Balano-Ligurian margin
Revised radiolarian ages for the sedimentary cover of the Balagne ophiolite (Corsica, France). Implications for the palaeoenvironmental evolution of the Balano-Ligurian margin
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DOI：
10.2113/gssgfbull.179.3.289
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发表时间：
2008-05
影响因子：
--
通讯作者：
T. Danelian;P. D. Wever;M. Durand-Delga
中科院分区：
文献类型：
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作者：
T. Danelian;P. D. Wever;M. Durand-Delga
根据新的和修订的放射虫化石证据，重新评估了覆盖巴拉涅蛇绿岩的放射虫的年龄。最古老的放射虫硅质岩被确定为两个构造单元中的上加洛阶-下加洛阶：San Colombano和Novella。这是迄今为止从利古里亚海洋的蛇颈龙中发现的最古老的年龄之一。一个重要的地层间隙，跨越加洛韦早期Kimmeridgian间隔，被指定之间的放射虫和覆盖（和局部冲沟）圣Colombano浅水石灰岩（子单元I）。我们现在可以确定，放射虫软泥积累，直到晚Kimmeridgian在Balagne边缘的远端部分（SC III亚单位和Novella单位），而海西基底的碎片落入Balagne盆地在晚Kimmeridgian-Tithonian。
The age of radiolarites covering the Balagne ophiolite is reassessed based on new and revised radiolarian fossil evidence. The oldest radiolarian cherts are dated as upper Bathonian-lower Callovian in two tectonic units: San Colombano and Novella. These are amongst the oldest ages available so far from ophiolites of the Ligurian ocean. An important stratigraphic gap, spanning the Callovian-early Kimmeridgian interval, is specified between radiolarites and the overlying (and locally gullying) San Colombano shallow-water limestones (sub-unit I). We can now specify that radiolarian ooze accumulated until the late Kimmeridgian in the distal parts of the Balagne margin (sub-unit SC III and Novella unit), while fragments of Hercynian basement fell into the Balagne basin during the late Kimmeridgian-Tithonian.