Measurement of the thickness of sediment bodies in the Johnsbach Valley using geophysical methods

This master’s thesis deals with the sediment power in the front Johnsbachtal. The goal is to find out using geophysical methods, how high the sediment body is on the original valley floor. In this case, a Indicate in meters how thick this layer is. For application here are geoelectrics and georadar. It was also Test measurements carried out with hammer strike seismics, but these showed, that the depth of penetration for the present question is far from it’s enough. Explosive seismics and other stronger seismic impulses were not available for financial and legal reasons (nature reserve). The Measurements were carried out at three locations: A measurement profile was about 200 Meters below the Neuweggraben at 0.8 km of road, another approx. 200 m above the Langgriesgraben at road kilometers 2.8 and a third on Height of the Fehringer Kreuzgraben at road kilometers 4.0. The measurements of geoelectrics showed that the sedimental power in the front Johnsbachtal can be estimated at 40 50 meters. The basis for this statement is the Measurement at the height of the Langgriesgraben up to a depth of about 70 meters, which Ground rock at a depth of about 45 meters. The other two measurements, below the Neuweggraben and at the height of the Fehringer Kreuzgraben up to a depth of approx. 35 meters. They showed up to the full penetration depth. not the entire cross-section of the sediment body, when measured below the New Way Trench, however, was an approach to the deepest point of the Detect sediments. This leaves the maximum sediment power in this The area is also estimated at 40 50 meters. Measurements with the georadar on the valley floor achieved with 50 MHz antennas a maximum penetration depth of 40 meters. They did not show any foundations in the full penetration depth, which confirms the statement of geoelectrics.本硕士论文围绕约翰斯巴赫谷（Johnsbachtal）前缘的沉积物展开研究，其目标为借助地球物理方法（geophysical methods），探明原始谷地上方沉积物体的高度，并以米为单位标注该沉积层的厚度。本次研究采用地电法（geoelectrics）与地质雷达（georadar）作为探测手段。此外还开展了锤击地震法（hammer strike seismics）测试，但结果显示，针对本研究问题，该方法的探测深度远不足以满足需求。受经费与法律限制（该区域为自然保护区（nature reserve）），无法使用爆炸地震法（explosive seismics）及其他强地震脉冲探测手段。 本次探测共设置3处测区：第一处测线位于诺伊韦格拉本（Neuweggraben）下方约200米处，对应道路里程桩号0.8km；第二处测线位于朗格里茨格拉本（Langgriesgraben）上方约200米处，对应道路里程桩号2.8km；第三处测线位于费林根十字格拉本（Fehringer Kreuzgraben）附近，对应道路里程桩号4.0km。 地电法探测结果显示，约翰斯巴赫谷前缘的沉积物厚度可估算为40~50米。该结论的依据来自朗格里茨格拉本测区的探测数据：本次探测最大深度约70米，在约45米深度处揭露了基岩（ground rock）。其余两处测区（诺伊韦格拉本与费林根十字格拉本）的探测最大深度仅约35米，虽未完整获取沉积物体的全部剖面，但在诺伊韦格拉本测区的探测中仍得以触及沉积物的最深点位置。因此该区域的最大沉积物厚度仍可估算为40~50米。 在谷地上开展的地质雷达探测采用50MHz天线，最大穿透深度达40米。本次探测在最大穿透深度范围内未发现基岩，这一结果印证了地电法的探测结论。