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Found 15 results.

Magnetotelluric investigations in the Spremberg area (eastern Germany)

New magnetotelluric (MT) data were collected in the Spremberg area (Brandeburg, eastern Germany) at 22 sites along 2 perpendicular profiles. All sites were equipped with five-component broad-band MT stations recording three magnetic field components and two horizontal electric field components. The main objective of the study was to assess the utility of MT techniques for mineral exploration at depth in sedimentary basins and for a region which is affected by strong electromagnetic noise from various sources. In particular, we aim to quantify the electrical conductivity distribution of the top 0.1–5 km of the Earth’s crust to determine electrically conductive zones and their possible correlation with sulfide mineralization. <default:br/> Interestingly, the MT data were recorded during a series of very powerful geomagnetic storms (Kp index 5-9). During the storms (from 10-13 May 2024), the quality of the derived MT transfer functions was generally much higher than for the geomagnetically quiet periods.<default:br/> This data publication (10.5880/GIPP-MT.202403.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Magnetotelluric exploration of Zn-Pb mineralization in Stonepark

To meet the objectives of the European Green Deal, Europe requires an increase in the supply of raw materials. To extract these materials responsibly and sustainably the complex social, environmental and technical challenges and how they interact need to be understood. The EU funded project VECTOR aims to assess these challenges and integrate them to produce human centred solutions. In this framework, minimally disruptive geological and geophysical studies have been carried out at three different locations across Europe. Stonepark is one of these locations located in the Irish Midlands in the Limerick Basin. The area includes potentially economic ore pods within Carboniferous carbonates and volcanic rocks. In Stonepark, new MT data were collected at a total of 108 sites in an area of 1.2 km x 5 km, of which 33 sites were equipped with five-component broad-band MT stations in concert with 75 two-component stations recording only the electric fields. The novel experimental layout using mobile electric field only stations sped up fieldwork while still allowing the use of local and remote reference techniques. Major goal of the study is to assess the utility MT techniques for mineral exploration at depth in sedimentary basins. In particular, we aim to quantify the 3D electrical conductivity distribution of the top 1–5 km of the crust from new MT data, in order to determine the location of electrically conductive ore mineralization. This data publication (https://doi.org/10.5880/GIPP-MT.202223.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Mapping of the Whitehill Formation in the Eastern Karoo Basin near Jansenville

The South African Karoo Basin, which is known for its potentially shale gas bearing formations, was the target of an extensive research programme launched by the Nelson Mandela University, South Africa. The aim of this project was to obtain a fundamental understanding of the geology, petrology and hydrology of the sedimentary layers. In 2014, Magnetotelluric (MT) measurements were conducted in the Eastern Karoo Basin to image the electrical conductivity structure of the shallow subsurface and to develop a three-dimensional (3D) model. Previous studies by Weckmann et al. (2007a, b) and Branch et al. (2007) identified the potentially shale gas bearing Whitehill Formation as an electrically conductive sub-horizontal layer, which covers large parts of the Karoo Basin. The increased interest in future shale gas exploration raised concerns regarding the potential impact on aquifers in this water scarce and fragile environment. Since the electrical conductivity is sensitive to fluids, imaging both, the black shale horizon and the deep aquifer system in this region was the ultimate goal of the MT study. Our field experiment is designed to serve as a baseline study before any activity regarding shale gas exploitation commenced. With high resolution 2D and regional 3D inversion and forward models several aquifers, the Whitehill formation and the possible source region of the Beattie Magnetic Anomaly could be mapped.This data publication (10.5880/GIPP-MT.201423.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Magnetotelluric Study of the Hangai Dome, Mongolia: Phase II

Surface deformation in the continental interior, away from active tectonic margins, is enigmatic, with the underlying mechanisms responsible not fully understood. Therefore, it is considered an open and important question in continental dynamics. The Hangai Dome, central Mongolia, is an ideal location to explore this because it is a high-elevation, low-relief, intra-continental region within the Mongolian plateau, between the Siberian and North China cratons, and within the Central Asian Orogenic Belt. The tectonic history of Central Mongolia is not well understood. It consists of several lithotectonic units that have influenced the formation and development of the region. The Hangai region has had intraplate volcanism throughout the Cenozoic, including as recently as the Holocene, in addition to older Mesozoic volcanic activity. It is characterized by dispersed, low-volume, alkali basaltic volcanism. Furthermore, major shear fault systems bound the Hangai region and central Mongolia. Our objective is to collect high-resolution magnetotelluric data to image the electrical resistivity structure of the crust and upper mantle beneath the Hangai Dome in order to better understand the processes and mechanisms responsible for intracontinental uplift and intraplate volcanism in this unique region, helping shed light on the Hangai region. Building on the successful first phase of the project (2016), a second phase was completed in 2017. We expanded our magnetotelluric measurement array: to the west along four new profiles; to the south, across the Gobi-Altai mountains; to the north, across the Bulnay fault segments; filling in the previous profiles for denser site spacing. This new grid of data is ~650 km long and ~400 km wide, with a nominal site spacing of 50 km for broadband measurements. In addition, we completed a small profile across the Tariat/Khorgo region and a reconnaissance profile in Zavkhan. This data report provides details on the data collection, the measurement site locations, the instrumentation, and the data format. This data publication (10.5880/GIPP-MT.201706.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Magnetotelluric and Radiomagnetotelluric measurements near Geyer in the Ore Mountains, Germany

The region of Geyer in the Ore Mountains (Erzgebirge) of Germany, situated approximately 110 kilometres south of Leipzig, has a long history of ore mining. The region is known for its deposits of tin, zinc, tungsten, molybdenum, copper, iron, silver, and indium. Due to this long history and known reservoir potential, this area was selected as a test site for the Innovative, Non-invasive and Fully Acceptable Exploration Technologies (INFACT) project. INFACT is a EU funded project aiming to foster new and innovative non-invasive methods for the exploration of new mineral deposits and is coordinated by the Helmholtz Institute Freiberg for Resource Technology (HIF) at Helmholtz-Zentrum Dresden-Rossendorf (HZDR). Within the framework of this project, the GFZ - German Research Centre for Geosciences, Potsdam, Germany, acquired magnetotelluric (MT) and radiomagnetotelluric (RMT) data near Geyer. The main objectives of these measurements were to map the shallow subsurface for mineral deposits and to evaluate the potential of these methods in densely populated areas with high levels of anthropogenic noise. This data publication (10.5880/GIPP-MT.201933.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Magnetotelluric Study of the Hangai Dome, Mongolia: Phase I

Surface deformation in the continental interior, away from active tectonic margins, is enigmatic, with the underlying mechanisms responsible not fully understood. Therefore, it is considered an open and important question in continental dynamics. The Hangai Dome, central Mongolia, is a natural laboratory to explore this question. It is a high-elevation, low-relief, intra-continental region within the Mongolian plateau. It is located between the Siberian and North China cratons and lies within the Central Asian Orogenic Belt. Central Mongolia has a complex tectonic history that is not well understood. It consists of several lithotectonic units that have influenced the formation and development of the region. The Hangai region has a long history of volcanic activity, including Cenozoic episodes of intraplate volcanism, which occurred as recently as the Holocene. It is characterized by dispersed, low-volume, alkali basaltic volcanism. Furthermore, major fault systems bound the Hangai region and large parts of central Mongolia. The processes and driving mechanisms responsible for creating the Hangai region remain largely unexplained. Therefore, we aim to collect high-resolution magnetotelluric data to image the electrical conductivity structure of the crust and upper mantle beneath the Hangai Dome in order to better understand the mechanisms responsible for intracontinental uplift and intraplate volcanism in this unique region. To achieve this objective a project was created, titled “Crust-mantle interactions beneath the Hangai Mountains in western Mongolia - Insights from 3-D magnetotelluric studies and 4-D thermo-mechanical modelling”. The first phase of the project was completed in 2016. Magnetotelluric data were recorded across the Hangai Dome in a grid (~400 by ~200 km), with a nominal site spacing of 50 km. Broadband measurements were acquired at each grid node and, additionally, long period measurements were acquired along two profiles. This data report provides details on the data collection, the measurement site locations, the instrumentation, and the data format. This data publication (https://doi.org/10.5880/GIPP-MT.201613.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Magnetotelluric measurements in the Mérida Andes, western Venezuela

The 100 km wide Mérida Andes extend from the Colombian/Venezuelan border to the Caribbean coast. To the north and south, the Mérida Andes are bound by hydrocarbon-rich sedimentary basins. This mountain chain and its associated major strike-slip fault systems formed by the oblique convergence of the Caribbean with the South American Plate and the north-eastwards expulsion of the North Andean Block in western Venezuela. In 2013, the Integrated Geoscience of the Mérida Andes Project (the GIAME project) was initiated to image the Mérida Andes on a lithospheric scale and to develop a dynamic model of their evolution by integrating wide-angle seismic, magnetotelluric and potential field data. Magnetotelluric (MT) dataset was acquired in 2015 along a 240 km long profile across the Mérida Andes. MT studies of orogens often reveal complex resistivity structures, typically associated with active deformation and characterized by high electrical conductivity zones. Fluids in fault systems and fluids derived from remineralization reactions of hydrous minerals often characterise high conductivity in active tectonic regimes. Cruces-Zabala et al. (2020) identified conductive zones with up to 10 km depth for the Maracaibo Basin and 5 km for the Barinas - Apure Basin. The Mérida Andes are charaterized by high resistivity separated by several conductive anomalies that corelate spatialy to the fault systems at the surface. A conductive zone a great depth (>50km) was identified as a projection of the detachment surface of the Trujillo Block to the east. This data publication encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Site characterization of the PIER-ICDP drill holes by imaging the subsurface electrical conductivity structure: local and regional structure beneath Mýtina and Neualbenreuth Maar (ConeEM)

The West Bohemian Massif as part of the geodynamically active European Cenozoic Rift System is characterised by ongoing magmatic processes in the intra-continental lithospheric mantle. A series of phenomena such as massive degassing of CO2 and repeated earthquake swarms make the Eger Rift a unique target area for European intra-continental geo-scientific research. The ICDP project "Drilling the Eger Rift" was funded to study the field of earthquake-fluid-rock-biosphere interaction. In the framework of this ICDP project, magnetotelluric (MT) experiments have been conducted to image the subsurface distribution of the electrical conductivity down to depths of several tens of kilometres as the electrical conductivity is particularly sensitive to the presence of high-conductive phases such as aqueous fluids, partial melts or metallic compounds. Based on recent MT experiments in 2015/2016, Munoz et al. (2018) presented 2D images of the electrical conductivity structure along a NS profile across the Eger Rift. It reveals a conductive channel at the earthquake swarm region that extend from the lower crust to the surface forming a pathway for fluids up to the region of the mofettes. A second conductive channel is present in the south of the model. Due to the given station setup along a profile, the resulting 2D inversion allows ambiguous interpretations of this feature. As 3D inversion is required to distinguish between the different interpretations, we conducted another MT field experiment at the end of 2018. This data publication (10.5880/GIPP-MT. 201810 .1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

MT_ANT2 - Magnetotelluric Measurements Around Neumayer Station III, Antarctica

Magnetotellurics (MT) is a geophysical deep sounding tool that can help decipher the deep hydrology and geology of Antarctica, in concert with more established and already applied geophysical methods, such as seismology, gravity, and magnetics. Electrical conductivity is an important physical parameter to identify properties of rocks and, perhaps more importantly, constituents within, such as fluids or mineralisation.The unique conditions of Antarctica, which is largely covered with ice cause technical issues, particularly with the electric field recordings, as highly resistive snow and ice at surface of Antarctica hampers contact of the E-field sensors (telluric electrodes) with the ground. The project was a feasibility study to address this principal problem and to test modified MT equipment of the Geophysical Instrument Pool Potsdam (GIPP) in the vicinity of the Neumayer Station III (NMIII) on the Ekström Ice Shelfon.This data publication encompasses a detailed report in .pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Integrated Geophysical Exploration Technologies for Deep Fractured Geothermal Systems. Report on the magnetotelluric data of project IGET.2006

The Integrated Geophysical Exploration Technologies for Deep Fractured Geothermal Systems project (I-GET) was aimed at developing an innovative strategy for geophysical exploration, particularly to exploit the full potential of seismic and electromagnetic exploration methods in detecting permeable zones and fluid bearing fractures.The proposed geothermal exploration approach was applied in selected European geothermal systems with different geological and thermodynamic reservoir characteristics: in Italy (high enthalpy reservoir in metamorphic rocks), in Iceland (high enthalpy reservoir in volcanic rocks) and in Germany and Poland (low to middle enthalpy reservoir in sedimentary rocks).The Groß Schönebeck in-situ geothermal laboratory, located 40 km north of Berlin in northeastern Germany, is a key site for testing the geothermal potential of deep sedimentary basins. The target reservoir is located in Lower Permian sandstones and volcanic strata, which host deep aquifers throughout the Northeast German Basin (NEGB). The laboratory consists of two 4.3-km-deep boreholes.The electrical conductivity of the subsurface is a very important parameter for characterizing geothermal systems as hot and mineralized (saline) fluids of deep aquifers can be imaged as regions of high electrical conductivity. In the first phase of the I-GET project, carried out in summer 2006, MT data was recorded at 55 stations along a 40-km long profile. In order to reduce the effect of the cultural noise, 4 remote reference stations located at distances of about 100 km from the profile were used. This profile is spatially coincident with a seismic tomography profile (Bauer et al., 2010). The main objective of the geophysical site characterization experiments was to derive combined electrical conductivity and P- and S-velocity tomographic models for a joint interpretation in high resolution.The data are provided in EMERALD format (Ritter et al., 2015). The folder structure and content is described in detail in Ritter et al., 2019. The project specific description is available in the associated data description file including information on the experimental setup and data collection, the instrumentation, recording configuration and data processing. Scientific outcomes of this project were published by Muñoz et al., (2010a, 2010b).

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