TY - JOUR

T1 - Verfeinerung der dreidimensionalen Kartierung quartärer Sedimente im Quakenbrücker Becken, Norddeutschland, mit Hilfe aeroelektromagnetischer Messungen

AU - Klimke, Jennifer

AU - Wiederhold, Helga

AU - Winsemann, Jutta

AU - Ertl, Gabriele

AU - Elbracht, Jörg

PY - 2013/6

Y1 - 2013/6

N2 - The increasing demand on using the subsurface raises the call for a better understanding of the depositional architecture. In this study, we demonstrate how 3D subsurface models can be improved by airborne electromagnetic data. The study area is located in the Pleistocene Quakenbrück Basin in Northern Germany. This overdeepened basin is fronted by a push moraine ridge and fi lled with Middle Pleistocene (Saalian) to Holocene sediments known from a limited amount of borehole data. In 2009, this area was target of an aeroelectromagnetic survey with the SkyTEM system. For the interpretation of SkyTEM resistivity data, a relation between grain size and resistivity was derived using resistivity borehole logs from the larger study area. The analysis of the data showed a positive correlation as resistivity increases with increasing grain size and permeability. Each stratigraphic layer was then modelled with the commercial software GOCAD® based on the geological and geophysical information as each sediment layer is characterised by a specifi c resistivity in the SkyTEM data. Our results demonstrate that by integrating airborne electromagnetic data into geological 3D models, the distribution of stratigraphic units can be modelled with higher lateral resolution due to higher data density. The resistivity-grain size relation can be applied to other study areas with comparable geological conditions. Saline groundwater can clearly be identifi ed and distinguished from non-saline regions in the Quakenbrück Basin by low resistivities.

AB - The increasing demand on using the subsurface raises the call for a better understanding of the depositional architecture. In this study, we demonstrate how 3D subsurface models can be improved by airborne electromagnetic data. The study area is located in the Pleistocene Quakenbrück Basin in Northern Germany. This overdeepened basin is fronted by a push moraine ridge and fi lled with Middle Pleistocene (Saalian) to Holocene sediments known from a limited amount of borehole data. In 2009, this area was target of an aeroelectromagnetic survey with the SkyTEM system. For the interpretation of SkyTEM resistivity data, a relation between grain size and resistivity was derived using resistivity borehole logs from the larger study area. The analysis of the data showed a positive correlation as resistivity increases with increasing grain size and permeability. Each stratigraphic layer was then modelled with the commercial software GOCAD® based on the geological and geophysical information as each sediment layer is characterised by a specifi c resistivity in the SkyTEM data. Our results demonstrate that by integrating airborne electromagnetic data into geological 3D models, the distribution of stratigraphic units can be modelled with higher lateral resolution due to higher data density. The resistivity-grain size relation can be applied to other study areas with comparable geological conditions. Saline groundwater can clearly be identifi ed and distinguished from non-saline regions in the Quakenbrück Basin by low resistivities.

KW - 3D model

KW - Aeroelectromagnetic method

KW - Geophysics

KW - Pleistocene basin

UR - http://www.scopus.com/inward/record.url?scp=84879383716&partnerID=8YFLogxK

U2 - 10.1127/1860-1804/2013/0023

DO - 10.1127/1860-1804/2013/0023

M3 - Artikel

AN - SCOPUS:84879383716

VL - 164

SP - 369

EP - 384

JO - Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften

JF - Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften

SN - 1860-1804

IS - 2

ER -