We present new evidence for neotectonic activity along the Harz Boundary Fault, a Cretaceous reverse fault that represents a key structure in northern Germany. For the fault analysis, we use a multimethod approach, integrating outcrop data, luminescene dating, shear wave seismics, electrical resistivity tomography (ERT) and numerical simulations. A recent sinkhole at the SSW-ward dipping and WNW–ESE striking Harz Boundary Fault exposes a NNE-ward dipping and WNW–ESE striking planar fault surface that cuts through unconsolidated debris-flow deposits thus pointing to young Lateglacial tectonic activity. The fault shows a polyphase evolution with initial normal fault movement and a later reactivation as an oblique fault with reverse and strike-slip components. A shear wave seismic profile was acquired to analyse the geometry of the fault and show that the Harz Boundary Fault is steeply dipping and likely has branches. Partly, these branches propagate into overlying alluvial-fan deposits that are probably Pleniglacial to Lateglacial in age. The outcrop data in combination with the seismic data give evidence for a splay fault system with steep back-thrusts. One of these back-thrusts is most likely the NNE-ward dipping fault that is exposed in the sinkhole. The lateral extent of the fault was mapped with electrical resistivity tomography (ERT) profiles. The timing of fault movement was estimated based on optically stimulated luminescence dating of the faulted debris-flow deposits using both quartz and feldspar minerals. Consistent feldspar and quartz ages indicate a good bleaching of the sediment prior to deposition. The results imply fault movements post-dating ~ 15 ka. Numerical simulations of glacio isostatic adjustment (GIA)-related changes in the Coulomb failure stress regime at the Harz Boundary Fault underpin the assumption that the fault was reactivated during the Lateglacial due to stress changes induced by the decay of the Late Pleistocene (Weichselian) Fennoscandian ice sheet.

我们为沿哈茨边界断裂的新构造活动提供了新证据，哈茨边界断裂是代表德国北部关键构造的白垩纪反向断裂。对于故障分析，我们使用一种多方法方法，将露头数据，明胶约会，剪切波地震，电阻率层析成像（ERT）和数值模拟相结合。SSW向浸水和WNW–ESE撞击哈兹边界断裂的最近的一个下沉洞暴露了NNE向浸水和WNW–ESE撞击平面的断层表面，切穿了未固结的泥石流沉积物，从而表明了年轻的晚冰期构造活动。断层表现为多相演化，初始为正常断层运动，后来又重新激活为具有反向和走滑分量的斜断层。采集到的横波地震剖面图分析了断层的几何形状，并表明哈兹边界断层陡峭地倾斜并且可能具有分支。这些分支在一定程度上传播到上冲积扇沉积物中，这些沉积物可能在年龄上是晚冰期到晚冰期的。露头数据与地震数据相结合，为反向冲断陡峭的断层系统提供了证据。这些反推力之一很可能是NNE向倾角断层，该断层暴露在下沉孔中。断层的横向范围用电阻层析成像（ERT）剖面图绘制。断层运动的时机是根据石英和长石矿物对断层泥石流沉积物的光激发发光年代来估算的。长石和石英的年龄一致表明沉积前沉积物有良好的漂白作用。结果表明，断层运动可追溯至〜15 ka。哈兹边界断层库仑破坏应力机制中与冰川等静压调整（GIA）相关的变化的数值模拟支持以下假设：该断层由于晚更新世（Weichselian）Fennoscandian的衰变引起的应力变化而在晚冰期重新活化冰盖。