Meso-Cenozoic negative inversion model for the Linhe Depression of Hetao Basin, China

The Linhe Depression is the largest tectonic unit in the Hetao Basin. The recently discovered commercial oil flow in the structural trap of wells JH2X and S5 has proved that the Meso-Cenozoic strata in the Linhe Depression have great exploration potential. Research on the kinematic model for the Mesozoic–Cenozoic Linhe Depression is important for analysing the geological conditions of hydrocarbon accumulation. In this study, field observations, seismic interpretation and scaled analogue modelling are performed. The results prove that the Linhe Depression experienced different stages of tectonic evolution, such as compressional depression (K1l), conversion from contraction to uniform subsidence (K1g), extensional rifting (E2–N2) and strike-slip deformation (Q), during the Mesozoic–Cenozoic eras. The kinematic model of negative inverted basins was first established with the early differential compression superimposed by the late extension. The seismic interpretation and analogue modelling results show that Jilantai Sag in the southern part of the Linhe Depression was subjected to compression from the Bayanwulashan fold–thrust belt on the NW side and the Helanshan fold–thrust belt on the SE side during Early Cretaceous time. Meanwhile, the Hanghou Sag in the northern part of the Linhe Depression was only compressed by the Langshan fold–thrust belt from the NW direction. The rifted structure generated by the extension from the SE direction during the Cenozoic Era resulted in the negative inversion of the pre-existing thrusts in different patterns. The intensity of negative inversion is controlled by several key factors, such as dip angle and the patterns of thrust faults, along with different basement textures. The morphological changes in the forebulge zone developed during Early Cretaceous time are responsible for the development of the segmented Central fault zones in the Hanghou Sag.

Sharing experimental data and facilities in EPOS: Updates on services for the analogue modelling community in the TCS Multi-scale Laboratories

<p>EPOS, the European Plate Observing System, is a unique e-infrastructure and collaborative environment for the solid earth science community in Europe and beyond. A wide range of world-class experimental (analogue modelling and rock and melt physics) and analytical (paleomagnetic, geochemistry, microscopy) laboratory infrastructures are concerted in a “Thematic Core Service” (TCS) labelled “Multi-scale Laboratories” (MSL). Sharing experimental facilities and data on analogue modelling of tectonic processes as well as on properties and applicability of different rock analogue materials are among the thematic areas that have been achieved during the current implementation phase of EPOS. The TCS Multi-scale Laboratories offers coordination of the laboratories’ network, data services, and trans-national access to laboratory facilities.</p><p> </p><p>In the framework of Transnational Access (TNA), TCS Multi-scale laboratories’ facilities are accessible to researchers across the world, creating new opportunities for synergy, collaboration and scientific innovation, according to trans-national access rules. TNA can be realized in the form of physical access (in-situ experimenting and analysis), remote service (sample analysis) and virtual access (remote processing). After three successful TNA calls, the 2020 and 2021 TNA calls have been suspended due to Covid-19 pandemic restrictions. A TNA call is now foreseen for 2022 offering access to a variety of experimental facilities and complementary expertise.</p><p> </p><p>In the framework of data services, TCS Multi Scale Laboratories promotes FAIR (Findable-Accessible-Interoperable-Re-Usable) sharing of experimental research data sets through Open Access data publications. Data sets are assigned with digital object identifiers (DOI) and are published under open CC BY licences. They are thus citable in all relevant scientific journals. A dedicated metadata schema (following international standards that are enrichiched with disciplinary controlled community vocabulary) eases exploration of the various data sets in a TCS catalogue. With respect to analogue modelling, a growing number of analogue modelling data sets include analogue material properties (friction and rheology data) and modelling results (images, maps, graphs, animations) as well as software (visualization and analysis). The main repository for data sets is currently GFZ Data Services, a domain repository for Geosciences, hosted at GFZ German Research Centre for Geosciences, but others are planned to be implemented within the next years.</p><p> </p><p>The EPOS TCS Multiscale Laboratories framework will lay the foundation for a comprehensive database of rock analogue materials, a dedicated bibliography, and will facilitate the organization of community wide activities (eg. meetings, benchmarking, etc.) to stimulate collaboration among analogue laboratories and the exchange of know-how.</p><p> </p>

3D-Printed Tool Shoulder Design for the Analogue Modelling of Bobbin Friction Stir Weld Joint Quality

A variety of tool shoulder designs comprising three families i.e. blade, spiral and circular shaped scrolls, were produced to improve the material flow and restrictions to avoid the tunnel void. The bobbin tools were manufactured by 3D printing additive manufacturing technology using solid filament. The butt weld joint was produced by each tool using plasticine as the workpiece material. The apparent surface features and bi-colour cross-sections provided a physical flow comparison among the shoulder designs. For the bobbin friction stir welding (BFSW), the tool shoulder with a three-spiral design produced the most stability with the best combination of the flow patterns on surface and cross-sections. The circular family tools showed a suitable intermixing on the surface pattern, while the blade scrolls showed better flow features within the cross-sections. The flow-driven effect of the shoulder features of the bobbin-tool design (inscribed grooves) was replicated by the 3D-printed tools and the analogue modelling of the weld samples. Similar flow patterns were achieved by dissimilar aluminium-copper weld, validating the accuracy of the analogue plasticine for the flow visualization of the bobbin friction stir welding.