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）前缘的沉积体特征展开研究，旨在通过地球物理方法探明原始谷地上方沉积体的高程（即沉积层厚度，单位为米）。本次研究采用的地球物理方法包括地电法（geoelectrics）与地质雷达（georadar）；此外还开展了锤击地震法（hammer strike seismics）测试，但结果显示，针对本研究的问题，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），无法使用爆炸地震法（explosive seismics）及其他强震源手段。 本次测量共设置三个测点：第一个测线位于道路里程桩号0.8km处的诺伊韦格拉本（Neuweggraben）下游约200米处；第二个测线位于道路里程桩号2.8km处的朗格里斯格拉本（Langgriesgraben）上游约200米处；第三个测点位于道路里程桩号4.0km处的费林格克罗伊茨格拉本（Fehringer Kreuzgraben）附近。 地电法测量结果显示，约翰斯巴赫谷前缘的沉积体厚度估算为40至50米。该结论的依据来自朗格里斯格拉本附近的测量数据：该测线探测深度达约70米，在45米深度处揭露了基岩。另外两个测点（诺伊韦格拉本下游及费林格克罗伊茨格拉本附近）的最大探测深度约为35米，虽均达到了最大探测深度，但并未完全揭露沉积体的完整截面；不过在诺伊韦格拉本下游的测量中，研究人员得以接近沉积物的最深点，由此可估算出该区域的最大沉积体厚度同样为40至50米。 在谷地上使用50MHz天线开展的地质雷达测量，最大探测深度可达40米。该测量在最大探测深度范围内未发现基岩，这一结果验证了地电法的结论。