Based on old detailed mining maps and own observations in the Hallstatt salt mine, we reinterpret the structure of the Hallstatt evaporite body of the Upper Permian to Lower Triassic Haselgebirge Fm. within the Northern Calcareous Alps (NCA). The Haselgebirge Fm. represents a rocksalt mylonite with abundant lenses of sulphates, mudstones and limestones. In comparison to published results of analogue modeling we interpret the present shape of the Hallstatt body as a WNW–ESE elongated compressive teardrop-like diapir. This is overprinted by NNE–SSW shortening and dominantly sinistral shearing along a W-trending shear zone. The internal structure shows steeply dipping rock units and foliation. Earlier dextral ductile shear fabrics of likely late Early Cretaceous age are preserved in sulphate rocks and are subsequently overprinted by mylonitic fabrics in rocksalt and cataclastic fabrics in other rocks. The low strength of halite results in recent subvertical shortening and a strain rate ε˙ of 8 × 10−10 [s−1] is deduced from deformed subhorizontal boreholes. This value is similar to such strain rates (10−10 to 10−9 s−1) estimated by the halite grain size distribution from other salt mines in the NCA and thus indicative of sub-recent formation of the halite microfabrics.

中文翻译：

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哈尔施塔特蒸发岩体的结构（奥地利北部钙质阿尔卑斯山）：走滑剪切叠加的压缩底辟？

根据旧的详细采矿图和自己在哈尔施塔特盐矿的观察，我们重新解释了上二叠统到下三叠统哈塞尔山组的哈尔施塔特蒸发岩体的结构。在北钙质阿尔卑斯山 (NCA) 内。Haselgebirge Fm。代表具有丰富的硫酸盐、泥岩和石灰岩透镜体的岩盐糜棱岩。与已发表的模拟建模结果相比，我们将哈尔施塔特体的当前形状解释为 WNW-ESE 拉长的压缩泪滴状底辟。这是由 NNE-SSW 缩短和沿 W 趋势剪切带的主要左旋剪切叠加的。内部结构显示出陡峭倾斜的岩石单元和叶理。可能在早白垩世晚期的早期右旋韧性剪切织物保存在硫酸盐岩石中，随后被岩盐中的糜棱质织物和其他岩石中的碎屑织物套印。岩盐的低强度导致最近的近垂直缩短，并且从变形的亚水平钻孔推断应变率为 ε˙ 为 8 × 10−10 [s−1]。该值类似于通过来自 NCA 中其他盐矿的岩盐粒度分布估计的应变率（10-10 到 10-9 s-1），因此表明岩盐微结构是近期形成的。