BlenderGIS Tutorial PART 6 - The Model

Farisberg graben - A Rheingraben structure incorporated into the Jura thrust-and-fold belt. Regional Context: The Tabular Jura, the eastern flanking plateau of the Late Eocene/Early Oligocene (~35 mln year) extensional Rheingraben system is made up of a series of 1-3 km wide NNE trending half-grabens, normally tilting with a rollover into an eastern bounding fault. The normal fault and graben structures of the Tabular Jura (herein called Rheingraben structures) can be traced southwards into our study area of the Jura fold-and-thrust belt (JFTB), a Late Miocene/Early Pliocene folded detachment slap pushed in front of the Alps. The northern part of the Tabular Jura is thereby incorporated in the JFTB influencing thrust and folding. The Rheingraben structures acted as pre-existing zones of motions oblique to the compressional folding, leading to transfer structure displacing and termination Jura fold and thrust trends; Rheingraben structures on the other hand are also mapped as being passively incorporated in the folding. Farisberg graben (FAG) is a clear example of a Rheingraben structure incorporated into a Jura fold, i.e., the Farisberg anticline (FAA) and has the following characteristics: In the roof of the FAA the FAG appears as a NNE striking, 1 km wide graben structure with flanking normal faults. The eastern flanking normal fault shows a large throw to the West, whilst the western flanking fault shows a lesser throw, thereby a halfgraben feature is indicated. Internally the FAG is dissected by a more complex fault zone connecting the two graben flanking faults, suggesting lateral movement along it. In the North, the graben structure terminates abruptly at the FAA thrust and a direct northern continuation across the FAA thrust is not seen. According to our fold and thrust restoration model, the northern continuation of the FA graben is to be found to the East at Langenwil where a similar graben feature (The Chräiegg graben CRA) is mapped within the Passwang anticline (PSA). The FAG and CRA is offset by some 2.2 km compatible with a 4 km northwards transport along a trust cutting oblique (29deg) to the graben feature. In the South, where the FAA southern limb increasingly steepens, the graben appears to bend sharply towards the East and the faults dissecting the vertical FAA flanks can be interpreted as rotated normal faults. Our working hypothesis is that the graben structure in the roofs of the FAA displays its original spacial orientation and is progressively folded into the southern limb of the FAA anticline .The Farisberg graben appears to cut by the thrust within the Opalinuston and transported northwards. A continuation within the Balsthal syncline is likely but no seismic or other data exist to verify this yet.