Understanding the structural controls and geochronology of diverse mineral deposit types, including iron oxide–Cu–Au (IOCG), porphyry Cu–Mo ± Au (porphyry), and epithermal vein-type (epithermal) systems within the Andean margin, remains a fundamental challenge in economic geology. This study integrates structural mapping, kinematic analysis, and geochronology to constrain the Cretaceous–Eocene tectonic evolution of the Coastal Range and Principal Cordillera in northern Chile (31° and 31°30′S) and its influence on the formation of El Espino (IOCG), Llahuín (porphyry cluster), and La Crucita (epithermal) systems. Our new data delineate three distinct tectonic stages. Stage 1 (Early to late Early Cretaceous, ∼135–115 Ma) was characterized by transtensional deformation along the NNW-trending Atacama Fault System, establishing the structural framework for subsequent IOCG mineralization in the El Espino district (∼93–86 Ma). Stage 2 (Late Cretaceous, ∼115–87 Ma) marked by positive tectonic inversion of Mesozoic extensional basins, during which pre-existing basin-margin normal faults were reactivated as reverse-oblique structures. A new Re–Os molybdenite age of 87.51 ± 0.23 Ma from Central Porphyry in the Llahuín porphyry cluster indicates that porphyry mineralization developed during this transpressional phase, approximately 4–5 Myr after formation of El Espino IOCG deposit. Stage 3 (Eocene, ∼45–35 Ma) reflects peak Incaic compression and significant crustal thickening. A new U–Pb zircon age of 40.7 ± 2.2 Ma from a granodiorite in the La Crucita district marks the southernmost expression of the Paleocene–Oligocene epithermal-porphyry metallogenic belt in this region. The distinct spatial and temporal distribution of IOCG, porphyry, and epithermal deposits reflects contrasting tectonic regimes, demonstrating that structural evolution exerted primary control on mineralization style and location. We conclude that inherited Mesozoic basin architectures, together with their subsequent tectonic inversion, imposed first-order controls on the timing and localization of mineral systems across the Andes orogen.

The Andes of central Chile between 33° and 34°S comprise two major tectonic domains: the Western Principal Cordillera, corresponding to the Abanico Basin, and the Eastern Principal Cordillera, represented by the Aconcagua Fold-and-Thrust Belt. The Abanico Basin developed as a symmetric extensional basin bounded by the Cerro Renca–Portezuelo de Chada Fault to the west and the El Diablo Fault to the east under an E–W extensional regime during the Middle Eocene–Oligocene. It was subsequently inverted during the Early Miocene, forming a bivergent contractional system, although shortening was preferentially accommodated along its eastern margin. However, the geometry, timing, and tectonic significance of this inversion remain poorly constrained. This study integrates brittle structural analysis, geological mapping, deep geometric reconstruction, and palinspastic restoration of regional cross sections to constrain the structural evolution of the basin and its role in Andean deformation. The results reveal distinct structural domains preserving evidence of the pre-extensional architecture of the Western Principal Cordillera and indicate a minimum shortening of 64–67 km across the Principal Cordillera at the latitude of Santiago. Early Miocene inversion was initiated between 21 and 22 Ma along the blind El Maipo Fault, coeval with synorogenic deposition of the basal Farellones Formation, while the San Francisco Fault controlled emplacement of the La Obra Pluton (19–20 Ma). Following Middle Miocene reactivation, the El Diablo Fault system acted as a crustal-scale magmatic conduit controlling emplacement of Miocene intrusions and major porphyry systems such as Río Blanco–Los Bronces and El Teniente. In contrast, the San Ramón and San Francisco faults evolved as purely compressional thrust systems after basin inversion. These results demonstrate that inherited extensional basin architecture exerted a first-order control on Andean shortening, magma ascent, and porphyry emplacement during Miocene orogenesis in the Central Chilean Andes.

The assessment of ground motion vibrational energy harvesting (VEH) potential remains largely unexplored. Unlike mature renewable resources such as solar or wind energy, no standardized frameworks currently exist to quantify how much energy can be realistically harvested from real ground vibrations. This knowledge gap limits the strategic deployment of VEH technologies and constrains their integration into self-powered sensing systems. This study introduces a novel, systematic methodology to evaluate the theoretical harvesting potential of electromagnetic energy harvesters (EMEHs) subjected to real seismic excitations. The proposed workflow comprises six stages: data acquisition, signal preprocessing, event identification (qualification, characterization and classification), device selection, energy harvesting simulation, and potential power estimation. Both natural and anthropogenic vibration sources, including earthquakes, microseisms, mining blasts, and heavy vehicle traffic, are explicitly considered. The methodology is applied to a mining environment in northern Chile using continuous seismic records. Distinct yet partially overlapping power ranges are identified across different event classes, highlighting the strong dependence of harvestable energy on local vibrational characteristics. Spatial energy density maps further reveal preferential deployment zones for EMEHs devices, underscoring the strong spatial dependence of the energy resource and the importance of characterizing local vibrational features when evaluating harvesting feasibility and robustness. By shifting the focus from device-level optimization to resource-level assessment, this work establishes a replicable foundation for evaluating seismic vibrations as an energy resource. The framework represents an initial step toward unlocking the potential of ground motion VEH, including natural events, and enabling its future integration into sustainable, self-powered monitoring infrastructures.

The Lluta Valley, in northern Chile provides an exceptional natural laboratory to investigate the crustal architecture of the western margin of the Altiplano Plateau. Previous subsurface studies in this region have been limited by the extensive Miocene volcanic and fluvio-alluvial cover. In this study, we applied local earthquake tomography using over 26,000 P- and S-wave arrivals recorded by a temporary network of 38 seismic stations to determine a high-resolution 3D Vp/Vs model. Results reveal a complex crustal structure characterized by low Vp/Vs anomalies (1.55-1.70) with low to moderate Vp values (5.2-6.0 km/s) associated with rigid metamorphic and intrusive lithologies such as the Belen Metamorphic Complex and Paleocene intrusions. In contrast, high Vp/Vs anomalies (1.80-1.90) with low Vp (4.5-5.2 km/s) spatially correlate with major fault systems, including the Ausipar Fault, the Oxaya Anticline, and the strike change of the Socoroma-Tignamar Fault System, interpreted here as a zone characterized by the interaction of several regional faults. These high Vp/Vs anomalies are interpreted as fractured and hydrated crustal domains, potentially influenced by pre-existing structural systems, that could locally modulate deformation and fluid migration. Our model supports a mixed-skin fold-and-thrust belt architecture, where rigid basement blocks are uplifted above Neogene units. Notably, high Vp/Vs anomalies are spatially linked to previously proposed strike-slip zones associated with the development of the Bolivian Orocline, suggesting that transcurrent deformation may influence the distribution of crustal heterogeneities and fluids-related within the forearc. Our findings demonstrate the influence of crustal heterogeneity and active subduction dynamics on the tectonic evolution of the Lluta Valley and the western Altiplano Plateau margin, providing insights into upper-crustal architecture, fluids-related pathways, and Andean orogenic evolution.

In orogenic provinces, tectonic inversion structures provide a coherent explanation for the distribution of many architectural elements. Nevertheless, the lack of direct constraints on orogenic growth, crustal thickening, and synorogenic deposits has led to a persistent material-balance problem. Uncertainty regarding the structural mechanisms responsible for mountain building has, in turn, contributed to conflicting interpretations about tectonic evolution. In this study, we propose a novel crustal-scale tectonic model, integrating multi-scale geological and geophysical constraints, together with new tomographic data, of the Inner Andean forearc in northern Chile. This model presents new interpretations about the final structural configuration, putting emphasis on the role of inherited structures and long-lived orogenic architectures. From one-to-one correlation between Vp/Vs ratio distributions and well-constrained surface expressions of regional-scale structures, stratigraphic sequences, and intrusive rocks, we stand out two principal structural systems, which control the subsurface architecture of this portion of the Andean forearc. The first consists of tectonic inversion–related structures, which acted as a major conduit for Late Cretaceous–Paleocene magmatic emplacement, similarly to the role played by the Domeyko Fault System during the Late Eocene–Early Oligocene magmatic phase. The second structure corresponds to an east-verging, low-angle, and thick-skinned thrust system characterized by large displacements, which decapitated and displaced earlier inverted normal faults. The interaction between inherited extensional faults reactivated by positive tectonic inversion and subsequently decapitated by east-verging thrusts represents an efficient mechanism for orogenic growth. This structural configuration provides a coherent explanation for the migration and deformation of imbricated thrust systems through thick-skinned fold-and-thrust belts and supports the interpretation of the inner Andean forearc as a critical wedge–type orogenic system.

Abstract The Central Andean Cordillera between 22°–24°S contains among the highest elevations and largest ignimbrite eruptions on Earth. Cenozoic crustal shortening is a major contributor to orogenic thickening and, while deformation in the upper crust is reasonably well constrained, deeper crust and lithospheric structures remain less understood. From 2022 to 2024, we deployed 298 nodal and 36 broadband seismometers across the Andes in northern Chile and Argentina and calculated high‐frequency receiver functions (RFs) to identify discontinuities in the crust and mantle from the coast to the foreland. In the Andean forearc, we image the oceanic crust top and Moho discontinuities where amplitudes gradationally increase along dip, indicating a transition in the overlying lithology from serpentinized mantle, to hot and coupled mantle wedge. Beneath the Puna Plateau, we image a complex gradational/layered Moho with thinner crust (depth ∼58 km bsl ) beneath the arc compared to thicker crust (depth ∼64 km bsl ) under the eastern Puna plateau with changes in Moho depth likely related to lithospheric removal processes. In the upper crust, we observe the well‐known Altiplano‐Puna Magma Body and additional widespread low velocity zones (<30 km bsl ) throughout the entire Puna, interpreted as additional regions of mid to upper crustal partial melt zones. Beneath the Eastern Cordillera and Santa Barbara thrust belt are a set of west‐dipping discontinuities consistent with the Main Andean Detachment system. These discontinuities merge into the low velocity zones in the Puna at a depth of ∼18–20 km possibly indicating a systemic connection between shortening structures and plateau magmatism.

This study reveals the seismic signature of the 1973 Chilean coup d'& eacute;tat by analyzing historical paper seismograms from September 1973. The continuous traces of the seismic activity preceding, during, and after the military coup were recorded by a Teledyne Geotech seismometer installed near (similar to 2 km) the presidential palace La Moneda. Our analysis revealed that distinct seismic patterns corresponded to specific societal activities, such as the morning commute and nighttime quietness. The seismic records captured the upheaval caused by the coup, including the military intervention, the bombing of La Moneda palace, and the subsequent imposition of a national curfew. The latter led to a significant reduction in anthropogenic noise making it easier to detect seismic events with enhanced clarity. To reconstruct the events of September 1973, we offers a unique perspective on the recent history of Chile. It also highlights the importance of seismic and scientific records as elements of cultural heritage worthy of preservation and recognition. In addition, it underlines the close link between Chile's seismological characteristics and the profound influence they have had on the shaping of the country's identity serving as an invaluable source of inspiration for artistic representations of natural hazards and disasters. Finally, the article emphasizes the imperative of preserving historical scientific records, not only as invaluable resources for advancing scientific understanding, but also as foundational elements for fostering transdisciplinary collaborations. The safeguarding of these records facilitates the interplay between science and art, creating new pathways for the dissemination of complex scientific knowledge, while inspiring creative expressions that engage with and reflect on Chile's cultural and natural history.

To better understand factors controlling the distribution of volcanoes, plate coupling along the subducting plate interface, and the transition from normal to flat slab subduction, we have determined high-resolution Vp, Vs and Vp/Vs models in the central Chile subduction zone where normal slab subduction transits to flat slab subduction. In the study region spanning latitudes of 22 degrees to 31 degrees S, volcanoes to the north of latitude 25.5 degrees S are underlaid by intensive intermediate-depth earthquakes, but those to the south are correlated with very few. Based on velocity features, we proposed that volcanoes to the north are likely caused by partial melting of mantle wedge by incorporation of fluids released during the dehydration reactions of various hydrous minerals in the slab that are responsible for inducing intermediate-depth earthquakes, while volcanoes to the south are likely caused by subslab hot materials migrating upwards through the tear or gap due to the transition from normal subduction to flat subduction. Along the plate surface constructed based on our inverted velocity models and relocated earthquakes, higher plate coupling is spatially correlated with lower Vp/Vs values and fewer earthquakes, whereas lower plate coupling is correlated with relatively higher Vp/Vs values and intensive small earthquakes. These features suggest that the plate coupling state is controlled by the existence of fluids along the plate interface, with high degree of fluids reducing plate coupling and causing the creep deformation. In the region where the flat slab subduction is evident, there exist apparent high velocity anomalies above the intraslab seismicity. This indicates that some buoyant materials such as oceanic plateaus, aseismic ridges and seamount chains that featured high velocity anomalies were subducted with the slab and caused the nominal flat subduction.

In the context of mining exploration, local earthquake tomography serves as a valuable complementary tool, applicable across varying scales from greenfield to brownfield projects. Nevertheless, interpreting body-wave velocity anomalies within tomographies poses a significant challenge, which largely depends on the expertise of the analyst and the availability of information. Addressing this challenge, this paper proposes a geostatistical analysis to effectively compare and enhance the information extracted from tomographies ranging from lower to higher resolutions. The data utilized in this study correspond to the tomographic inversion values of Mantos Rojos (MR) and Radomiro Tomic (RT) porphyry copper deposits situated within the Chuquicamata District in northern Chile. MR has a resolution of 2 × 2 km2, comparatively lower than RT’s resolution of 1 × 1 km2, yet both share the same spatial zone. This study evaluated the discernment capabilities of lower-resolution tomography (MR) in comparison to its higher-resolution counterpart (RT) using turning bands simulation. The simulated Vp/Vs values of MR were compared against RT seismic tomography data. Visual validation revealed that simulated Vp/Vs values from P- and S-wave velocity values of MR can identify the low Vp/Vs anomalies (< 1.7). Moreover, spatial analysis compared the experimental variograms for MR realizations and for RT values in preferential directions for Vp/Vs ratios, finding a correspondence between both spatial tools. Finally, geological validation was carried out by comparing the simulation results with geological maps of the study area and copper grades obtained through drilling campaigns provided by CODELCO, where spatial patterns indicative of mineralization and larger-scale geological features like the West Fault were identified. Our research has practical implications because, through geostatistical simulations, the grid dimensions of seismic tomography of MR can be reduced and still identify low Vp/Vs anomalies within the area of study, being consistent with the lower-resolution validation grid of RT. Our findings demonstrate the efficacy of geostatistical methods in enhancing exploration decision-making by providing insights into subsurface geological features and their relationship to mineralization. This approach not only improves the efficiency and success rate of mineral exploration projects but also minimizes environmental impact by allowing for more targeted and informed exploration activities.

In this study, we assemble body wave arrival times from earthquakes occurring in the central Chile between 2014 and 2019, and Rayleigh wave phase velocity maps at periods of 5-80 s from ambient noise Empirical Green's functions in Chile. By jointly using body wave arrival times and surface wave dispersion data, we refine the Vs model and improve earthquake locations in central Chile. Compared to other velocity models in the region that are determined by individual data type, our joint inversion Vs model shows better consistency with the intraslab seismicity distribution as well as the Moho and slab interfaces. Our Vs model clearly images an eastward dipping high velocity band of 40-50 km thick, corresponding well to the thickness of the Nazca plate estimated by receiver function imaging and thermal modelling.Overall, the intraslab seismicity distribution spatially correlates well with the slab high velocity anomalies except for along the subduction paths of the Copiapó Ridge and Juan Fernández Ridge. Additionally, parallel low-velocity stripes are imaged beneath the subducting plate, which are likely associated with the accumulated melts. The joint inversion velocity model also resolves widespread low-velocity anomalies in the crust beneath the Central Volcanic Zone of the central Andes, likely representing crustal magma chambers for various volcanoes.

Seismic velocity models were compared with coseismic slip distributions for two megathrust earthquakes that occurred along the South American subduction zone. By analyzing the distribution of Vp/Vs ratios, we found that seismic anomalies with values higher or lower than the average coincide with the boundaries of the earthquake ruptures. In contrast, the regions characterized by intermediate Vp/Vs values may represent a mechanical “sweet spot” where the physical properties create favorable conditions for sustained rupture propagation. Our methodology, which combines the Vp/Vs distribution and the analysis of coseismic slip models, could reveal the rupture‐prone regions and the likely magnitude of potential earthquakes, providing relevant information for seismic hazard assessment.

The Chilean Pampean flat slab subduction segment is characterized by the nearly horizontal subduction of the Nazca Plate within the depth range of 100–120 km. Numerous seismic tomography studies have been conducted to investigate its velocity structure; however, they have used only seismic body wave data or surface wave data. As a result, the existing velocity models in the region may have relatively large uncertainties. In this study, we use body wave arrival times from earthquakes occurring in central Chile between 2014 and 2019, as well as Rayleigh wave phase velocity maps at periods of 5–80 s from ambient noise empirical Green’s functions in Chile. By jointly using body wave arrival times and surface wave dispersion data, we refine the VS model and improve earthquake locations in the central Chile subduction zone. Compared with previous velocity models, our velocity model better reveals an eastward-dipping high-velocity plate representing the subducting Nazca Plate, which is 40–50 km thick and is more consistent with the slab thickness estimated by receiver function imaging and thermal modeling. Overall, the intraslab seismicity distribution spatially correlates well with the slab high-velocity anomalies except along the subduction paths of the Copiapó Ridge and Juan Fernández Ridge. Additionally, parallel low-velocity stripes are imaged beneath the subducting plate, which are likely associated with the accumulated melts. The joint inversion velocity model also resolves widespread low-velocity anomalies in the crust beneath the Central Volcanic Zone of the central Andes, likely representing crustal magma chambers for various volcanoes.

The Tuina prospect is situated in northern Chile, approximately 50 km east of Calama in the Antofagasta Region. It lies within the Eocene-Oligocene metallogenic belt, which is home to world-class copper deposits, including Chuquicamata, El Abra, and Radomiro Tomic. To characterize the subsurface architecture, we deployed a temporary seismic network of 37 geophones and applied Local Seismic Tomography to derive seismic velocity models. The results show intermediate Vp/Vs values in the prospect area, suggesting a highly fractured environment consistent with surface geological data. Additionally, we identified a high Vp/Vs anomaly with a northwest orientation, reaching depths of up to 20 km and intersecting the anomaly associated with Tuina. We propose that this structure is not a simple lineament, as previously suggested, but rather a concealed fault system controlling the eastern boundary of the Eocene-Oligocene metallogenic belt. In this context, the so-called Calama-Olacapato-El Toro lineament represents a complex fault system playing a key role in the region’s structural evolution and mineralization. Based on this, we present a five-stage conceptual model explaining how fluid migration from subduction enables the formation of mineral prospects controlled by this fault system. The tomography results correlate with surface data, demonstrating the method’s effectiveness for geophysical exploration.

The Chilean subduction zone is one of the most seismically active regions globally,characterized by extensive intermediate-depth seismicity in the slab.In this study,we construct a new earthquake catalog for northern Chile using seismic waveforms assembled for the period of 2014-2019,from which 320,070 P-wave and 232,907 S-wave first arrivals are obtained for 25,763 earthquakes.Grid search location method NonLinLoc is applied to determine initial earthquake locations and double-difference location method is used to improve relative event locations.The distribution of earthquakes exhibits distinct patterns to the north and south of 21°S.There are many more earthquakes deeper than～150 km to the south of 21°S,while relatively fewer to the north.The intraslab earthquakes shallower than～80 km generally reveal a distinct double seismic zone,and the gap between the two seismic planes disappears at a depth of approximately～80 km,followed by a concentration of seismicity in the depth range of～80-150 km.In the deeper slab,there exist several seismicity clusters with distinct earthquake activities down to～300 km.These characteristics shown in slab seismicity are likely caused by different mechanisms and can be helpful for understanding the subduction process.

The Andean Margin hosts alternating regions of “flat” and “normal” subduction, which includes the Pampean flat slab that extends from central Chile to Argentina. The discovery of an unusual travel time anomaly beneath the high Andes above the flat slab motivated a study to investigate the lithosphere in this region. Leveraging extensive archived seismic data from both Chile and Argentina, we performed a large-scale joint inversion of P and S body wave arrival times from earthquakes, and surface wave dispersion measurements from earthquakes and ambient noise. We created 3D Vp, Vs and Vp/Vs models using at least an order of magnitude more data than previous studies with about an 80% reduction in grid spacing. Our models corroborate results from previous studies: (1) a high velocity, high Vp/Vs region associated with a cool, slightly hydrated and depleted mantle above the flat slab, and (2) a low velocity structure beneath the high Andes interpreted as an overthickened crustal root, with our results showing that the root extends to just above the flat slab. Curiously, our models also reveal two low velocity zones within and below the flat slab seismic zone that have not been previously reported. Notably, the decrease in velocity is more pronounced in Vp than Vs. We postulate that the eastern low velocity anomaly is likely due to hot asthenosphere heating the slab, although no melting is occurring as the Vs is not significantly reduced. The western low velocity anomaly, which spatially correlates with the Juan Fernandez Ridge (JFR), we postulate is either due to the presence of supercritical fluids trapped within the JFR or an increase in silica content possibly linked to petit spot volcanism.

Crustal architecture plays a secondary yet critical role in porphyry copper formation by controlling the transport and focusing of metal-rich hydrothermal fluids. Although upper crustal structures often guide porphyry emplacement, their identification though geological mapping alone remains challenging, necessitating geophysical imaging for robust subsurface characterization. The Late Eocene-Early Oligocene porphyry copper belt of the Chilean Andes hosts one of the worlds largest concentrations of copper mineralization. Within this belt, the El Abra (EA), Radomiro Tomic (RT), and Chuquicamata (CH) deposits (similar to 22 degrees S)-collectively referred to as the EA-RT-CH cluster-are spatially associated with the N-S strike-slip fault West Fault System (WFS) in the Domeyko Cordillera of northern Chile. We present a 3D subsurface model beneath the EA-RT-CH cluster constructed from local earthquake tomography using seismic velocities (Vp, Vs) and the Vp/Vs ratio, integrated with comprehensive structural interpretation. Low Vp/Vs anomalies (similar to 1.6-1.7) at depths <= 3 km spatially coincide with intrusive complexes hosting porphyry intrusions, interpreted as quartz-rich, mechanically rigid cores. Conversely, high Vp/Vs anomalies (similar to 1.8-1.9) delineate structural corridors aligned with the WFS and a previously unrecognized NW-SE high-angle lineament that segments the intrusive complexes. This regional-scale NW-SE lineament not only intersects low Vp/Vs anomalies but also the WFS. We attribute Vp/Vs variations primarily to differences in rock composition, fracture density, and fluid presence rather than mechanical rigidity alone. Our results reveal a transpressional subsurface architecture beneath the EA-RT-CH cluster, where structural intersections between the arc-parallel WFS and major concealed, NW-trending lineaments exert control on segmentation, emplacement, and exhumation of porphyry copper clusters in northern Chile. These findings provide new structural and geophysical constraints for one of the worlds most economically significant porphyry copper districts.

Detections of slow slip events (SSEs) are now common along most plate boundary fault systems at the global scale. However, no such event has been described in the south Peru - north Chile subduction zone so far, except for the early preparatory phase of the 2014 Iquique earthquake. We use geodetic template matching on GNSS-derived time series of surface motion in Northern Chile to extract SSEs hidden within the geodetic noise. We detect 33 events with durations ranging from 9 to 40 days and magnitudes from Mw 5.6 to 6.2. The moment released by these aseismic events seems to scale with the cube of their duration, suggesting a dynamic comparable to that of earthquakes. We compare the distribution of SSEs with the distribution of coupling along the megathrust derived using Bayesian inference on GNSS- and InSAR-derived interseismic velocities. From this comparison, we obtain that most SSEs occur in regions of intermediate coupling where the megathrust transitions from locked to creeping or where geometrical complexities of the interplate region have been proposed. We finally discuss the potential role of fluids as a triggering mechanism for SSEs in the area.

We present an updated and validated seismic catalog for the northern Fennoscandian region, focusing on postglacial faults from the Merasjärvi fault system in the southwest to the Iešjávri fault system in the northeast. This work involved a comprehensive review of continuous waveforms derived from open datasets from 2007 to 2015 and processed using the Regressive ESTimator algorithm. The primary objective was to refine the delineation of seismicity along the above-mentioned postglacial faults and highlight their seismic potential. Our analysis revealed distinct waveform patterns originating primarily from two main sources: approximately 15% were associated with areas mapped as postglacial faults, and the remainder of the events outside these areas, 89%, were concentrated in areas with active mines. Compared to previously reported events in the Fennoscandian Earthquake Catalogue (FENCAT), we observed a 22% increase in seismic activity within postglacial fault zones. These results demonstrate that the Regressive ESTimator algorithm not only improves the detection of tectonic seismicity but also effectively identifies seismic signals resulting from mining activities in the study area. The Merasjärvi, Lainio–Suijavaara, Palojärvi, and Maze and Iešjávri fault systems appear to form a continuous deformation complex of approximately 300 km long, which we propose naming the Merasjärvi–Stuoragurra fault complex.