This report contains the results of the two thesis studies that finalise a combined MSc--programs of Reservoir Geology and Science Communication. The first part of the report comprises the multi-scale data (kilometers to meters scale) analysis of a) the large--scale architecture of the subsurface Daly Waters Arch which was obtained from seismic data interpretation; and b) fracture pattern characterisation by outcrop measurements and drone imagery in the Tomkinson Province. Both the Daly Waters Arch and the Tomkinson Province are located in the largely undeformed Palaeo-- to Meso--Proterozoic Greater McArthur Basin in the Northern Territory, Australia. In July 2019, a geological fieldwork was conducted in the Tomkinson Province to collect the fracture data with the drone. In this research, the Daly Waters Arch and the Tomkinson Province have been geologically linked based on seismic and fracture data. By discussing analog cases of far-field deformation, these results have been placed in a larger context of large--scale basin deformation.

The second part of the report focuses on the Netherlands, where ambitious goals have been set for the implementation of geothermal energy in the energy transition. During the gas production in Groningen, a negative social perspective towards mining operations, in general, was developed. For the implementation of geothermal energy, an approach for the communication of technical uncertainties between the initiators and the local public of a geothermal project is designed in this study. Technical uncertainties that are present in geothermal energy implementation in the Netherlands have been identified during semi-structured expert-interviews with different stakeholders in the spectrum of geothermal energy. The approach addresses guidelines for the communication of the context, the goal, the technical uncertainties present in the geothermal project, the main communicating actors, their reference frames, and the situation in which the communication process takes place.

During this thesis, 2D modelling using the MOVE software suite is performed on a fold and thrust belt in the French Prealps. The area of interest is called the Couspeau area and is 72 km2. In this area, Vocontian basin sediments deposited during the Jurassic and Cretaceous can be found. The area contains well exposed fold and thrust structures. The oldest structures begin in the West, while the younger ones can be found in the East. All thrusts strike approximately N-S. These thrusts were assumed to be formed by the second Alpine orogeny. A structural map of the area was created in QGIS version 3.12.0 using geologic maps from the BRGM and using fieldwork data from Applied Earth Sciences students collected during the AESB2430 course at TU Delft. Subsequently, four E-W orientated cross sections of the area were constructed. These sections were restored using MOVE to verify if the interpretations were geologically feasible. 2D forward modelling was then applied to discover possible types of structural mechanisms which were active in this area. Possible mechanisms include fault-bend folding and regular folding. Fault propagation folding was assumed to be a suitable mechanism, but didn’t produce satisfactory forward models. Strain circles were added during forward modelling to analyse what kind of deformation is caused by different thrusting mechanisms. The restored sections were also used to calculate the total amount of shortening in the area, and how much of this shortening was caused by folding or faulting. The total amount of shortening was 24%, from which 38% was caused by faulting and 62% by folding.

The structural evolution, phases and amount of deformation, and the strain distribution of the sedimentary cover of a geologically complex area of 270 km2 in the French subalpine chains (Southeast of France; in the surroundings of the village La Motte-Chalancon) were deduced from the modelling of two folded and faulted competent layers (Tithonian and Barremian formations) both in 2D and 3D. These models were constructed from collected geological data such as BRGM (Bureau de Recherches Geologiques et Minères) geological maps, previous Bachelor’s fieldwork data, new field data and the study of aerial photographs (Google Earth). A grid of 20 vertical 2D cross-sections (10 N-S, and 10 E-W) was generated which was then imported and digitized in the geological modelling software package Move and the 3D model of the competent layers was built, validated and restored to its initial configuration prior to deformation by first removing each fault displacement (Fault Parallel Flow method) and then unfolding each structure (Flexural Slip method) in Move, showing deformation and shortening in two directions: N-S and E-W. The amount of deformation in both directions was estimated from the 3D model. Major deformation took place in the N-S direction with a maximum of 21% shortening for both layers which corresponds to an absolute shortening of 4067m for the Tithonian layer and 4076m for the Barremian layer. Less deformation took place in the E-W direction with a maximum of 9% to 10% for the Tithonian and Barremian horizons respectively which corresponds to an absolute shortening of 1697m and 1976m respectively. This resulted in an area reduction of 16% and 19% of the original area prior to deformation for the Tithonian and Barremian, respectively.
Two phases of deformation over geological time were deduced from the orientations of the folds and faults present in the studied area. The presence of NW-SE trending folds and thrust faults (e.g. Mt D’Angele fault, Pommerol fault, or Chalancon fault) along with a conjugate strike-slip system (of one oriented N-S and one NE-SW) reflects the NE-SW compressional stress regime of the first stage of deformation which is related to the Pyrenean phase of the Alpine Orogeny. The second stage, the Alpine phase, which resulted in E-W contractions, is associated with the formation of domal/basinal structures as well as folds with plunging fold axes within the studied area. The northeastern part of the studied area exhibits different fault trends. Two tear faults (L’Aiguille and Ruelles fault), a dextral N-S strike-slip fault (Establet fault), and two E-W trending reverse faults (Peyssias and Hidden fault) resulted from N-S compression. These are related to the first phase of the Pyrenean stage, and then later partly rotated during the latter phase of the Alpine stage.
The strain maps produced from the 3D model displaying the high-/low-strain zones of the area mainly show E-W and NW-SE trending strain zones which confirm the direction of the main stress regime of the Pyrenean compressional phase oriented NW-SE.

The geological history of the McArthur Basin (NT Australia) is poorly understood. It consists of five onshore Paleo- to Mesoproterozoic packages with mainly siliciclastic and carbonate rocks, with cumulative thicknesses up to 15km. The basin contains the world’s oldest hydrocarbons, principally hosted in unconventional reservoirs in the Wilton Package. Fluid flow in these reservoirs is related to natural, reactivated or induced fractures. Characterizing the fracture network is an important part of predicting fluid flow. This study tries to link the geological history to the generation of fractures.

The geological history needs to be better understood to characterize the fracture network. In this study seismic, well, outcrop and geophysical data are integrated to construct a cross section that links outcrops (Batten Fault Zone and Broadmere Complex) with the subsurface (Beetaloo Sub-basin). The literature in combination with the cross section is used to revise the geological history.

A fieldwork is conducted to study fracture geometries on outcrops of the Wilton Package that are analogues to subsurface fracture networks. A drone is used to image fracture pavements at an order (10²m) that is normally missed by geologists (10¹m) and satellite images (10³m). The Tanumbirini-1 well, located in the sub-basin, provides a FMI log for interpreting fractures in the subsurface. A key objective is to differentiate fractures associated with fracture drivers like regional stress, folds and faults.

This study identified two unconformities in the seismic data, corresponding to two deformation events. The Carpenteria Event between the Wilton Package and the Inacumba Group is associated with a dominantly N-S oriented stress field and the Borroloola Event within the Inacumba Group corresponds to a mainly E-W oriented stress field. Both events created their own fracture sets and are observed on outcrops and in the subsurface. The tectonic stress is σ₁ at the surface but σ_H,max in the Beetaloo Sub-basin. Fracture generation in the sub-basin happened at another stress regime than the surface outcrop analogues, making any direct comparison less reliable. Hence this study gives a prediction of the fracture density and permeability trends in the sub-basin. A conceptual model of the subsurface permeability is proposed where the permeability trend is mainly E-W oriented.

A three-dimensional geological model has been constructed of a 49 square km area in the sub-Alpine chains in the French Drôme department. The area was situated in the Vocontian Basin, which was an epicontinental sea situated at the western margin of the Alpine Tethys Ocean, between former continents of Gondwana and Laurasia. Formations of limestones and marls have been deposited over a time span of approximately 80 Ma from the Late Jurassic to the Early Cretaceous, which can be classified into eight distinct formations. This was followed by two phases of deformation. First, the counter-clockwise rotation of Iberia into Europe inducing S-N compression in this area. Second, the collision of Adria with the European continent inducing E-W compression. Both events uplifted the area by an estimated 2500 to 3000 m.
This thesis uses data collected during the second year fieldwork (course AESB2430) of the Applied Earth Sciences bachelor at Delft University of Technology. The cross sections and geological map from this fieldwork were revised where necessary. Three new cross-sections were constructed along the north, east, and west boundaries of the area for more coverage. All cross-sections were digitized using the Move software package. To check whether these were geologically feasible, they were restored to their pre-deformation state by removing the effect of faulting and folding. These cross-sections form the basis for a 1:25 000 scale three-dimensional model. Horizon surfaces were created between cross-section horizons using spline interpolation and fault surfaces using linear interpolation
Fauld displacements are removed and an unfolding is performed on the 3D model, in an attempt to reconstruct a balanced pre-deformational setting. The result is a viable model, with some inaccuracies such as gaps and overlaps between formation surfaces and slight variation s in layer thickness. The aim of this 3D model is to aid the understanding of the configuration of rocks and of the structural evolution of the area. The average shortening due to deformation for cross-sections was found to be 14.71 %. The surface reduction value of the area is found to be 8.2 푘푚 or 14.3 %.
The direction of shortening is primarily in the S-N, due to the Iberian collision, and to lesser extent in the E-W direction, due to the Adriatic collision.