Subsurface sedimentary strata in northern Switzerland, such as the Middle Triassic Upper Muschelkalk, are attracting interest as potential reservoirs for CO2 sequestration and for geothermal energy production. Characterizing facies in such strata aids prediction of reservoir properties in unexplored areas. Although well studied elsewhere, the Swiss Upper Muschelkalk has received little attention despite containing the southern-most deposits of the Central European Basin. The Upper Muschelkalk represents the deposits of a storm-dominated, homoclinal carbonate ramp, developed during a basin-wide 3rd-order transgressive–regressive cycle. Our facies analyses of nine boreholes across northern Switzerland reveal 12 lithofacies, eight lithofacies associations and four types of metre-scale 5th-order cycles corresponding to at least 23 short orbital eccentricity cycles. During the 3rd-order transgression, crinoidal bioherms developed across Switzerland followed by deep-ramp environments. Subsequently, tempestites were deposited up to and after the basin-wide maximum flooding surface. Lateral tempestite correlations indicate that Switzerland lay within an open-marine, mid-ramp environment during almost half of the depositional history. Mid-ramp deposits pass upwards to prograding shelly shoals, which sheltered a back-shoal lagoon containing patchy oolitic shoals. At the top of the Upper Muschelkalk, back-shoal sediments give way to coastal sabkha facies, which were overlain by oolitic shoals during a marine transgression. Shortly thereafter the top of the Upper Muschelkalk was dolomitized by brines from an overlying hypersaline environment that was later removed by a basin-wide erosive event. Overall, the paucity of porous shoal facies, unlike in southern Germany, has resulted in poor primary reservoir properties in the Upper Muschelkalk of Switzerland.

中文翻译：

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瑞士北部上Muschelkalk（中三叠世Schinznach组）的相和沉积环境

瑞士北部的地下沉积地层，例如中三叠纪上穆斯克尔克山，正成为潜在的二氧化碳封存和地热能储集层。在这样的地层中表征相有助于预测未勘探区域的储层性质。尽管在其他地方进行了充分的研究，但瑞士上游Muschelkalk尽管受到中欧盆地最南端的沉积物的影响，却很少受到关注。Muschelkalk上层代表了一个在一个盆地范围的三阶海侵-海退循环中形成的风暴主导的单斜碳酸盐岩斜坡的沉积物。我们对瑞士北部的9个钻孔进行了相分析，发现有12个岩相，八个岩相协会和四种类型的米尺度5阶周期对应于至少23个短轨道偏心率周期。在三次入侵期间，整个瑞士都出现了环状生物虫，随后出现了深部斜坡环境。随后，在盆地范围内最大洪泛面之前和之后都沉积有风暴岩。侧面的陨石相关性表明，瑞士在近一半的沉积历史中都处于海洋中坡的环境中。斜坡中段的沉积物向上延伸到有壳的浅滩，这掩盖了一个后部泻湖泻湖，里面有片状的浅滩。在上Muschelkalk的顶部，后滩沉积物让位于沿海sabkha相，在海侵过程中被浅滩覆盖。此后不久，上覆的高盐环境中的盐水使上Muschelkalk的顶部白云石化，随后又因全盆地侵蚀事件而将其清除。总体而言，与德国南部不同，多孔浅滩相的匮乏导致瑞士上穆斯克尔卡尔克的主要储层物性较差。