Airborne/UAV Multisensor Surveys Enhance the Geological Mapping and 3D Model of a Pseudo-Skarn Deposit in Ploumanac’h, French Brittany

Taking advantage of a multi-sensor (multispectral and magnetic) drone survey, we address the detailed geological mapping and modeling of a mineralization in its geological environment. We stress that these high-resolution data allow us to bridge the gap between field observations and a regional aeromagnetic survey. On the one hand, the combination of multispectral imagery with field geological observations enhances detailed geological mapping. On the other hand, the combination of field magnetic susceptibility measurement and their use in detailed to regional magnetic modeling, constrained respectively by UAV-borne and airborne magnetic surveys, allows deriving a model of the mineralization consistent across the scales. This is demonstrated in a case study in a complex polyphased magmatic-metamorphic environment on the coast of French Brittany. The target area hosts a pseudo-skarn mineralization, exhibiting an outstanding magnetic anomaly. The combination of remotely sensed and field data allows deriving a realistic conceptual and geometrical model of the magnetic mineralization in its geological environment, tightly constrained by field observations and measurements.

A new magnetic modeling method for magnetic levitation rotary table

Precision machining fields require the worktable to have a large-scale multi-degree-of-freedom motion capability. In order to provide a more accurate magnetic model for the control strategy decoupling process and the size parameter optimization design process of the maglev rotary table. This paper proposes a new magnetic modeling method based on the Two-Dimensional Harmonic method. Different from the existing harmonic method, this method simultaneously considers the tangential and radial magnetic field changes of circumferential magnetic array. And it eliminates the edge effect of the magnetic flux density distribution in the radial aperiodic direction. The magnetic force and torque are solved by the Lorenz integral formula and the Gaussian quadrature method. In order to verify the accuracy of the TDH method, the boundary element software RadiaTM is used for simulation, and a prototype is made for measurement. The experimental results shown that this method reduced the maximum error of the radial edge magnetic field from 104.19% to 3.29%. And it improved the calculation accuracy of magnetic force and torque by 60.74% and 84.39% respectively. This method does not rely on special example, and is beneficial to cross-platform applications. It is more suitable for realizing the magnetic modeling of the maglev rotary table with both rotational motion and large-stroke translational motion.

Coupled design approach for an integrated GaN-based wireless power transfer rotating system

This paper concerns the design of a high-frequency GaN-based rotating transformer confined by conductive materials. The design approach combines the high-order spectral element method for the magnetic modeling, an electronic circuit model, and the finite element method for the thermal modeling. The objective of the design analysis is to minimize the ratio of core inertia to efficiency. Two different transformer topologies are considered, in which the power is either transferred in the axial or radial direction. The resulting designs are compared in terms of efficiency, core inertia, and transferred power. The radial design shows the best performance within the optimization problem.

Magnetic Modeling and Potential Hydrocarbon Trap Over Yola and Environs Upper Benue Trough Northeastern Nigeria

With a renewed interest to search for hydrocarbons in the hinter land of Nigeria’s inland basin climaxed after the discovery of a rewarding oil prospects around the Kolmani river II as recently announced by the National Oil Company, the Nigeria National Petroleum Corporation (NNPC). This research was based on analyzing the high-resolution aeromagnetic data over the study area using the Oasis Montaj TM software, in order to get the total magnetic intensity map as well as the residual map, band pass filter map was used to generate magnetic aureoles. GM-SYS module of the Oasis montaj was used for the modeling exercise, the models reveal the horst and graben architecture of the basement with the grabens serving as depocentres, hydrocarbon potentials of the area were highlighted using magnetic aureoles mapping.

Magnetic modeling of the West Iberian Margin constrained by new geophysical data

<p>The nature of the J magnetic anomaly off West Iberia and its implications on the kinematic and geodynamic evolution of the margin has been addressed by several studies, with several distinct interpretations and resulting models. The main reason for this is that one single geophysical dataset (the IAM-9 seismic profile on the Iberia Abyssal Plain) has until now imaged the respective crust and was available as constraint, leaving a large degree of uncertainty for interpretation and modeling. New geophysical imaging of the structure of J anomaly and nearby domains, preferably in different margin sectors, would then be essential to cast new light on the discussion on the Iberian margin evolution. We here present new constrained magnetic modeling for two profiles across the J anomaly off Iberia, in the Tagus and in the Iberia Abyssal Plain, respectively. These profiles were recently surveyed for wide angle and reflection seismics and for magnetic data, during the FRAME-2018 survey. The joint processing of wide angle and reflection seismic data revealed with unprecedented detail the velocity structure and the tectono-stratigraphy along the profiles. Here, we use these results as constraints for magnetic modeling of the measured anomalies, namely for detailed definition of the basement topography and identification of the different domains. Magnetic modeling allowed inferring the relative contribution of each layer and the existence of additional magnetic sources, such as intrusive bodies in exhumed mantle domains. Regarding the J anomaly, we show that it cannot be attributed only to magnetization contrasts between different layers. The J anomaly is rather the result of an anomalous highly magnetized source body, associated with a locally thicker crust, which claims for an abnormal magmatic composition with strong enrichment in iron oxides. We discuss possible origins for the found structure and composition of the J anomaly off Iberia, as well as implications of the new magnetic modeled profiles for the margin conjugation and kinematics.</p><p><span>The author would like to acknowledge the financial support  FCT through project</span><span> UIDB/50019/2020 – IDL.</span></p>