Schistes lustrés from Corsica to Hungary : back to the original sediments and tentative dating of partly azoic metasediments
Schistes lustrés from Corsica to Hungary : back to the original sediments and tentative dating of partly azoic metasediments
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从科西嘉岛到匈牙利的光彩片岩：回到原始沉积物和部分无冰质变沉积物的初步测年
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发表时间：
2003
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通讯作者：
M. Lemoine
中科院分区：
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作者：
M. Lemoine
阿尔卑斯山和科西嘉岛的Lustres（SL）是近无生气的侏罗纪-白垩纪变质沉积物，通常与蛇绿岩有关。它们来自消失的瓦莱州（N-Penninic）和皮埃蒙特-利古里亚（S-Penninic）海洋及其大陆边缘。
他们的年龄一般不太清楚。由于阿尔布·海姆和S.弗朗基在世纪初，他们被认为是在很长一段时间里主要是Liassic的年龄。我们现在知道SL的主要部分是白垩纪。
深海沉积物，特别是SL，是由半远洋-远洋背景（HPB）与当地或遥远的起源碎屑成分。HPB的性质，主要是由特提斯和世界各地的事件，是一个很大的帮助，至少粗略的地层标志;相比之下，碎屑材料是不是一个可靠的标志，因为它可能发生在不同的时间在不同的地方。HPB显示了几个连续的，10至40百万年。主要为泥质（A）或钙质（C）的长片段。侏罗-白垩纪SL沉积过程中可划分出7个幕：C1，石灰质Liassic ; A1，泥灰岩上Liassic ; C2，石灰质晚Liassic和早Dogger ; A2，泥质或放射虫质晚Dogger-早Malm ; C3，石灰质晚Malm ; A3，泥质或泥灰岩早白垩世; C4，石灰质晚白垩世。它们可以通过各自的主要岩性来识别，也可以通过它们从C1到C4的顺序来识别。几乎所有这些细分都在这里和那里被稀有化石所确定，这使得众多的azoic SL系列可以粗略地确定年代。
由于它们表现出非常不同的岩性，从远洋钙质软泥到黑色页岩和各种复理石和其他物质流沉积物，SL不能被认为是一个特定的，定义明确的相：它们不是阿尔卑斯山地球动力学演化的特定阶段的特征。
最后，一个可能的影响，全球性的事件提出了建议。第一，CCD深度的作用，受晚侏罗世早期和晚白垩世早期生物恢复。第二，与一级海平面升降事件的相关性：台地海侵与深海A事件大致同期，海退与深海C事件大致同期。
The Alpine and Corsican Schistes lustres (SL) are nearly azoic Jurassic-Cretaceous metasediments often associated with ophiolites. They are derived from both the vanished Valais (N-Penninic) and Piemont-Ligurian (S-Penninic) oceans and from their continental margins.
Their age is generally poorly known. Because of fossils discovered by Alb. Heim and by S. Franchi at the beginning of the 20th century, they were believed for a long time to be mostly Liassic in age. We know now that the major part of the SL is Cretaceous.
Deep-sea sediments, and particularly the SL, are made up of a hemipelagic-pelagic background (HPB) associated with detrital components of local or distant origin. The nature of the HPB, mostly conditioned by Tethyan and worldwide events, is of great help as an at least rough stratigraphic marker ; in contrast, detrital material is not a reliable marker because it may occur at different times in different places. The HPB exhibits several successive, 10 to 40 m.y. long episodes which are either predominantly argillaceous (A) or calcareous (C). During the deposition of the Juras-sic-Cretaceous SL, seven episodes can be distinguished : C1, calcareous Liassic ; A1, marly Upper Liassic ; C2, calcareous latest Liassic and early Dogger ; A2, shaly or radiolaritic late Dogger-early Malm ; C3, calcareous late Malm ; A3 shaly or marly early Cretaceous ; C4 calcareous late Cretaceous. They can be recognized, each one by its prevailing lithology, and all together by their succession in order from C1 to C4. Nearly all of these subdivisions are here and there dated by rare fossils, which allow for a rough dating of the numerous azoic SL series.
As they exhibit very different lithologies, from pelagic calcareous oozes to Black Shales and various kinds of flysch and other mass flow deposits, the SL cannot be considered as a specific, well-defined facies : they are not characteristic for a particular stage of the geodynamic evolution of the Alps.
Finally, a possible influence of worldwide events is suggested. First, the role of the depth of the CCD, governed by early late Jurassic and early late Cretaceous biotic recoveries. Secondly, the correlation with first order eustatic events : transgressions on platforms seem to be roughly coeval with A episodes in the deep sea, regressions with C episodes.