Two new reports from MapField

Published 26-10-2021

Two new reports about geological modelling based on tTEM data in the MapField project were published recently. A short overview is presented below, for more details, please follow the links.

Geological mapping in MapField LOOP-areas and demo sites

By Sandersen, P.B.E. & Kallesøe, A.J., 2021. GEUS Report 2021/36

This report describes the geological interpretations at four selected agricultural catchments from the Danish National Environmental Monitoring Program (LOOP) and two demo sites mapped as a part of the MapField Project. For each of the mapped areas, existing and newly acquired field data have been interpreted geologically in high detail. Mapping with the tTEM method (towed Transient Electro Magnetic method) has provided highly detailed data from the uppermost 50-70 m.

In the geological modelling we use the concept of ‘Geological Elements’ (GE’s), where the GE’s are defined as separate volumes of the subsurface that can be related to distinct parts of the geological history. Dividing the subsurface into GE’s has the advantage that it is only necessary to model the upper and the lower boundaries of GE’s consisting of multiple individual layers, resulting in a limited number of GE’s in the geological model. Based on the geological interpretations, input for subsequent statistical and hydrological modelling can be produced.

Example of a cross-section (LOOP 6), where tTEM data are shown as a 3D resistivity grid and SkyTEM data are visualized as single sounding poles.

MapField study area LOOP 2: Establishing a geological event chronology

By Sandersen, P.B.E. & Kallesøe, A.J., 2021. GEUS Report 2021/30. 

When modelling complex geology in 3D it is important to bring forward possible explanations of how the subsurface may have been formed and how the individual parts of the succession are related to each other. In this report it is described how information on the regional geological setting, interpretations of the local lithology and structure, and interpretations of the topography are combined to produce a local Geological Event Chronology.

The report describes the workflow and the interpretations that have led to establishing a Geological Event Chronology in the MapField LOOP 2 area in northern Jutland, Denmark.

Geological Event Chronology sketches from the LOOP 2 area.