The Chachahuén Volcanic Complex is an eroded Upper Miocene arc to back-arc volcanic system that was emplaced in the north-eastern edge of the Neuquén Basin, southern Mendoza province, Argentina. It was formed as the result of shallowing followed by steepening of the Nazca plate during Miocene-Pliocene, and is characterized by a volcanism which ranges from trachydacites to basalts. Thanks to erosion, the stratigraphy and the shallow plumbing systems of the volcano are well-exposed. A new evolution for the volcano stratigraphy is proposed, based on new field observations, satellite imagery, and incorporating the radiometric and petrological data of previous works. The stratigraphy is constrained around one main explosive event, recorded by a thick dacitic pyroclastic density current (PDC) deposit (the Corrales Ignimbrite) (>150m). The main units forming the Chachahuén Volcanic Complex are (1) the pre-dacite PDC deposits (trachydacitic to rhyolitic) Vizcachas Formation, (2) the thick Corrales Ignimbrite, (3) a post-dacite trachyandesitic PDC deposits (dominated by block and ash (BAF) deposits) and thick lava flows, and (4) thin mafic basaltic lava flows. The collapse of a large elliptical caldera occurred during the Trachyandesite phase. The main magma transport channels and feeders are sub-vertical dykes, which exhibit a radial distribution centred on the main caldera depression. Moreover, cryptodomes mainly preserved outside the rim of the caldera accommodated the transport and emplacement of the more silicic magma during the Trachyandesite phase.

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Granitic magma bodies form in the ephemeral part of magma mush systems and are emplaced by a variety of mechanisms in different tectonic settings. This study investigates how granitic magma emplacement processes and tectonomagmatic interactions assert control over the architecture of mush state pluton-scale magma transport pathways. The 1.45 Ga shallow-crustal Götemar pluton is a 4.5 km diameter circular pluton that consists of three granite units: a coarse-grained red granite, a medium-grained pale to red granite, and fine-grained pale microgranite sheets. We employed geological mapping supported by Anisotropy of Magnetic Susceptibility (AMS) to examine the magmatic and regional tectonic controls on late-stage magma transport in the Götemar granitic magma mush system. Multiple parallel arcuate subhorizontal microgranite and medium-grained granite sheets (from 0.1 to 10s of meters thick) were mapped within the pluton. The arcuate sheets pinch out from the northern part of the pluton toward the SE inferring magma propagation direction. A dominant set of vertical granitic sheets within the granite body strikes NW-SE. The AMS fabrics are contact-parallel in the main medium-grained granite body and indicate inflation. Within the microgranite sheets, the AMS fabrics are parallel to the sheet strike and support a sheet propagation direction to the SE. The Götemar pluton displays a clear link between arcuate (concentric) magma-transporting sheets and concentric strain-partitioning related to the intrusion of medium-grained granite magma. The vertical magma sheet orientations are consistent with an NE-SW extensional stress field that is associated with the extensional back-arc stress regime of the contemporary Hallandian Orogen.

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How the Earth’s crust accommodates magma emplacement influences the signals that can be detected by monitoring volcano seismicity and surface deformation, which are routinely used to forecast volcanic eruptions. However, we lack direct observational links between deformation caused by magma emplacement and monitoring signals. Here we use field mapping and photogrammetry to quantify deformation caused by the emplacement of at least 2.5 km³ of silicic magma in the Reyðarártindur pluton, Southeast Iceland. Our results show that magma emplacement triggered minor and local roof uplift, and that magma reservoir growth was largely aseismic by piecemeal floor subsidence. The occurrence and arrangement of fractures and faults in the reservoir roof can be explained by magmatic overpressure, suggesting that magma influx was not fully accommodated by floor subsidence. The tensile and shear fracturing would have caused detectable seismicity. Overpressure eventually culminated in eruption, as evidenced by exposed conduits that are associated with pronounced local subsidence of the roof rocks, corresponding to the formation of an asymmetric graben at the volcano surface. Hence, the field observations highlight processes that may take place within silicic volcanoes, not accounted for in widely used models to interpret volcanic unrest.

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X-ray transmission sorting is arguably the most successful ore sorting technique used in the mining industry today. In order to establish the suitability of X-ray transmission sorting for a specific ore deposit or raw material type, the current state of the art involves time-consuming and costly empirical testing. In this paper, we show how the success of X-ray transmission sorting can be reliably predicted based on X-ray radiographs that are quick and inexpensive to obtain for a large number of samples. We document this novel approach using a large suite of samples of scheelite ores from the Mittersill deposit in Austria. Using only the X-ray radiographs at a spatial resolution of 0.12 mm we quantify the volume of high-density scheelite at different spatial resolution. The results are compared to and validated by data obtained by computer tomography and scanning electron microscopy-based image analysis. The X-ray radiograph data set is then down sampled to spatial resolutions of 0.8 mm, 3.2 mm, 12 mm and 24 mm in order to gauge the optimum spatial resolution prior to any empirical testing. Upgrading curves can be calculated, and in combination with quantitative data obtained by complementary analytical methods, the mineralogical and chemical composition of concentrate and waste can be predicted. The workflow can be transferred without any problems to many other ore types with a significant density difference between ore mineral(s) and gangue minerals.@en

The multi-purpose research borehole at the Delftse Hout is the third of four seismic monitoring locations of the seismic monitoring network for the geothermal research project on the TU Delft campus (Geothermal Delft GTD, also known as DAPwell, https://geothermiedelft.nl/). For the geothermal research project, two deep wells (“a doublet” consisting of an injector and a producer) for geothermal energy extraction will be installed on the TU Delft campus next to the combined heat and power plant (“warmtekrachtcentrale - WKC”). The system will produce geothermal heat to supply the campus of TU Delft and part of the city of Delft.
The herein presented borehole describes the installation of a multi-purpose research borehole (called DAPGEO-02), which was installed in the period February - May 2022. DAPGEO-02 is part of a seismic monitoring system for the shallow and deeper subsurface in the vicinity of the planned geothermal doublet. The locations of all four stations are given in Figure 1. The monitoring network and the related research gathers knowledge about the current status of the subsurface on the basis of periodic data measurements, and possible seasonal effects.
Within the seismic monitoring network, three seismic monitoring stations have already been installed, respectively DAPGEO-01 on the proposed location of the geothermal project near the Leeghwaterstraat in Delft, DAPGEO-03 on the Kerkpolderweg in Delft, and ZH03 in on the Ackersdijkseweg in Pijnacker-Nootdorp (installed and equipped by KNMI).@en