New Ordovician–Silurian drill cores from the Siljan impact structure in central Sweden: an integral part of the Swedish Deep Drilling Program
New Ordovician–Silurian drill cores from the Siljan impact structure in central Sweden: an integral part of the Swedish Deep Drilling Program
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来自瑞典中部 Siljan 冲击构造的新奥陶纪-志留纪钻芯：瑞典深钻计划的组成部分
DOI：
10.1080/11035897.2012.692707
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发表时间：
2012
期刊：
影响因子：
1
通讯作者：
T. Vandenbroucke
中科院分区：
文献类型：
--
作者：
O. Lehnert;G. Meinhold;S. Bergstroem;M. Calner;J. R. Ebbestad;S. Egenhoff;Å. Frisk;J. Hannah;Anette E. S. Högström;W. Huff;C. Juhlin;J. Maletz;H. Stein;E. Sturkell;T. Vandenbroucke
来自欧洲最大的已知撞击构造（西尔扬陨石坑的遗迹）的新岩心为重建早古生代海洋环境和生态系统以及记录Baltoscandia沉积相、海平面和古气候的变化提供了新的可能性。撞击坑是“瑞典深钻方案”框架内“古生代同心撞击结构”项目的一个重要目标。已分析了两个核心部分：莫拉001和索尔伯格1。这些岩心剖面的沉积序列包括从特里马多世晚期到温洛克晚期的地层。我们的初步研究表明，不仅在该地区代表了瑞典的几个古典古生代单位，而且在西尔扬地区还保存了其他显着不同的相。在西尔扬构造的西部，中奥陶世石灰岩和Llandovery-Wenlock（志留纪）页岩序列之间出现侵蚀不整合面，代表了一个实质性的间断，并表明了一个延长的隆起和侵蚀时期。这可能与加里东逆冲岩席向西弯曲加载导致的前隆迁移有关。因此，瑞典的这一部分，以前被认为是一个稳定的波罗的海地区，可能受到波罗的海和劳伦特之间的加里东碰撞的影响。
New drill cores from the largest known impact structure in Europe, the relict of the Siljan meteorite crater, provide new possibilities to reconstruct Early Palaeozoic marine environments and ecosystems, and to document changes in sedimentary facies, sea level and palaeoclimate in Baltoscandia. The impact crater is an important target of the project “Concentric Impact Structures in the Palaeozoic” within the framework of the “Swedish Deep Drilling Program”. Two core sections, Mora 001 and Solberga 1, have been analysed. The sedimentary successions of these core sections include strata of late Tremadocian through late Wenlock ages. Our preliminary studies show not only that several of the classical Palaeozoic units of Sweden are represented in the area, but also that other significantly different facies are preserved in the Siljan district. An erosional unconformity representing a substantial hiatus occurs between Middle Ordovician limestone and a Llandovery-Wenlock (Silurian) shale succession in the western part of the Siljan structure and suggests an extended period of uplift and erosion. This may be related to forebulge migration due to flexural loading by the Caledonian thrust sheet to the west. Thus, this part of Sweden, previously regarded as a stable cratonic area, presumably was affected by the Caledonian collision between Baltica and Laurentia.