Establishing of the tectonic affinity and pre- Variscan evolution of the Brunovistulian microcontinent (Czech Republic) by U-Pb and Ar-Ar mineral dating of granitoid basement and cover sediments

跨欧洲缝合带将华力西欧洲与波罗的海古大陆的东欧边缘分隔开来。它是在从寒武纪到志留纪的几次重大事件中形成的。由于暴露不良和复杂的地质结构，许多关于其起源和演化的问题仍然悬而未决，我们的主要目的是调查的亲和力和早古生代，前华力西的Brunovistulian微大陆的演化及其在跨欧洲缝合带的作用。大部分Brunovistulian微大陆基底未暴露，但被新元古代和寒武-奥陶纪沉积物覆盖，很少有钻孔到达结晶基底。因此，我们将重点关注捷克共和国布尔诺附近的BVM西南部，那里基底和盖层暴露良好，地质关系清晰，华力西叠加有限。将对斯拉夫科夫地体基底的I型角闪石（花岗岩）闪长岩和英云闪长岩的几个侵入阶段的岩浆锆石进行定年，以确定结晶年龄并重建岩石的侵入历史。此外，40 Ar/39 Ar步进加热测年的岩浆角闪石和黑云母从相同的样品将进行建立内部一致的冷却年龄历史。 对中央基性岩带基底变形长英质凝灰岩/熔结凝灰岩层中的岩浆锆石进行定年，以确定结晶年龄，并阐明该带与东西两侧花岗岩类基底的关系。（“基底碎屑岩”）将通过原位单颗粒方法进行物源研究并确定其来源。将以砾岩层为目标，因为它们含有大量来自变质岩和火成岩的未成熟碎屑。当地衍生的花岗岩类和外来的含白云母的花岗岩类碎屑证明了砾岩和源区地质之间的密切联系，侵蚀产物是Brunovistulian微大陆起源的重要关键。

The Trans-European Suture Zone separates variscan Europe from the East European Craton margin of the palaeo-continent Baltica. It was formed during several major events lasting from the Cambrian to the Silurian. Due to poor exposure and a complex geological structure, many questions about its origin and evolution remain open.Our primary aim is to investigate the affinity and Early Palaeozoic, pre-Variscan evolution of the Brunovistulian microcontinent and its role in the Trans-European Suture Zone. Most of the Brunovistulian microcontinent basement is not exposed but covered by Neoproterozoic and Cambro-Ordovician sediments and few boreholes have reached crystalline basement. For this reason, we will focus on the southwestern part of the BVM around Brno in the Czech Republic, where basement and cover are well exposed, geological relations are clear and Variscan overprinting is limited.Magmatic zircon from several intrusive phases of I-type hornblende-bearing (grano)diorites and tonalites of the Slavkov Terrane basement will be dated to determine crystallization ages and reconstruct the intrusion history of the terrane. In addition, 40Ar/39Ar step-heating dating of magmatic amphibole and biotite from the same samples will be carried out to establish internally consistent cooling age histories. Magmatic zircons from deformed felsic tuff / ignimbrite layers in the Central Basic Belt basement will be dated to establish crystallization ages and elucidate the relation of the belt to the granitoid basement terranes to the west and east.Zircon and detrital white micas from Devonian clastic alluvial fan and alluvial sediments overlying the basement ("basal clastics") will be dated by in situ, single grain methods for as provenance study and establish their source. Conglomerate layers will be targeted as they contain abundant immature detritus derived from metamorphic and igneous rocks. Clasts of locally derived granitoids and exotic, muscovite-bearing granitoid clasts prove the close link between the conglomerates and the geology of the source areas and the erosional products hold an important key to the origin of the Brunovistulian microcontinent.