For the reconstruction of Alpine tectonics of the Eastern Alps, the evaporitic Permian to Lower Triassic Haselgebirge Formation plays a key role in (1) the origin of Haselgebirge bearing nappes, (2) the inclusion of magmatic and metamorphic rocks revealing tectonic processes not preserved in other units, and (3) the debated mode of emplacement of the nappes, namely gravity-driven or tectonic. Within the Moosegg quarry of the central Northern Calcareous Alps gypsum/anhydrite bodies are tectonically mixed with lenses of sedimentary rocks and decimeter- to meter-sized tectonic clasts of plutonic and subvolcanic rocks and rare metamorphics. We examined various types of (1) widespread biotite–diorite, meta-syenite, (2) meta-dolerite and rare ultramafic rocks (serpentinite, pyroxenite) as well as (3) rare metamorphic banded meta-psammitic schists and meta-doleritic blueschists. The apparent 40Ar/39Ar biotite ages from three biotite–diorite, meta-dolerite and meta-doleritic blueschist samples with variable composition and fabrics range from 248 to 270 Ma (e.g., 251.2 ± 1.1 Ma) indicating a Permian age of cooling after magma crystallisation or metamorphism. The chemical composition of biotite–diorite and meta-syenite indicates an alkaline trend interpreted to represent a rift-related magmatic suite. These, as well as Permian to Jurassic sedimentary rocks, were incorporated during Cretaceous nappe emplacement forming the sulphatic Haselgebirge mélange. The scattered 40Ar/39Ar white mica ages of a meta-doleritic blueschist (of N-MORB origin) and banded meta-psammitic schist are ca. 349 and 378 Ma, respectively, proving the Variscan age of pressure-dominated metamorphism. These ages are similar to detrital white mica ages reported from the underlying Rossfeld Formations, indicating a close source–sink relationship. According to our new data, the Haselgebirge bearing nappe was transported over the Lower Cretaceous Rossfeld Formations, which include many clasts derived from the Haselgebirge Formation and its exotic blocks deposited in front of the incoming nappe comprising the Haselgebirge Formation.

中文翻译：

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北钙质阿尔卑斯山脉（奥地利）中部的 Haselgebirge 蒸发混杂岩：二叠纪到下三叠纪 Meliata 洋裂谷的一部分？

对于东阿尔卑斯高山构造的重建，蒸发的二叠纪至下三叠统哈塞尔山组在（1）带推覆的哈塞尔山组的起源，（2）岩浆和变质岩的包裹体中发挥了关键作用，揭示了该地区未保存的构造过程。其他单元，以及（3）有争议的推覆体就位模式，即重力驱动或构造。在北部钙质阿尔卑斯山中部的 Moosegg 采石场内，石膏/硬石膏体在构造上与沉积岩透镜体、深成岩和亚火山岩以及稀有变质岩的分米到米大小的构造碎屑混合在一起。我们研究了各种类型的 (1) 广泛分布的黑云母-闪长岩、变正长岩，(2) 变辉绿岩和稀有的超镁铁质岩石（蛇纹岩、辉石岩）以及（3）稀有变质带状变砂岩片岩和变辉石蓝片岩。来自三个黑云母-闪长岩、偏玄武岩和偏玄武岩蓝片岩样品的表观 40Ar/39Ar 黑云母年龄范围为 248 至 270 Ma（例如，251.2 ± 1.1 Ma），表明岩浆结晶后冷却的二叠纪年龄或变质。黑云母-闪长岩和变正长岩的化学成分表明碱性趋势被解释为代表与裂谷相关的岩浆套件。这些，以及二叠纪到侏罗纪的沉积岩，在白垩纪推覆就位期间被合并，形成硫酸盐 Haselgebirge 混合岩。变玄武岩蓝片岩（来自 N-MORB 起源）和带状变砂岩片岩的分散的 40Ar/39Ar 白色云母年龄大约为。分别为 349 和 378 Ma，证明了以压力为主的变质作用的瓦利斯坎时代。这些年龄与下伏罗斯菲尔德地层报告的碎屑白云母年龄相似，表明源汇关系密切。根据我们的新数据，Haselgebirge 推覆岩被运输到下白垩统 Rossfeld 地层，其中包括许多源自 Haselgebirge 地层的碎屑，以及沉积在构成 Haselgebirge 地层的传入推覆体前面的奇异块体。