BUSCADOR RECOLECTA

[Description of methods used for collection/generation of data] Field measurements of P- and S-wave velocities using a Monolith A1220 Velocity Tester., Multiparamatetric petrophysical dataset of experimental measurments on borehole samples from Collinstown (Ireland). Contains measurements of Vp, Vs, density, resistivity, chargeability and magnetic susceptibility., VECTOR., Peer reviewed

Description of methods used for collection/generation of data] field measurements of P- and S-wave velocities using a Monolith A1220 Velocity Tester; and SM-20 susceptibility meter., Multiparamatetric petrophysical dataset of experimental measurments on borehole samples from the Spremberg (Germany). Contains measurements of Vp, Vs and Magnetic susceptibility., VECTOR., Peer reviewed

The data acquisition contract was funded by the "Programa estatal de fomento de la investigación científica y técnica de excelencia-subprograma estatal de generación de conocimiento" of the Ministry of economy and competitiveness and took place in 2015. Seismic data was successfully collected in Alhama de Murcia (Spain). The total amount of seismic reflection data collected was 13.2 km in 6 profiles NW-SE oriented. Technical specifications of the profiles: Receiver number: 240, Receiver interval: 2 m, Source: accelerated weightdrop 250 kg, Source interval: 6 m, Sample rate: 1 ms, Record time: 4 s. Contact people: Martínez-Díaz, J.; jmdiaz@geo.ucm.es and Carbonell, R.; rcarbo@ictja.csic.es, This work is part of the research project: “InterGeo”. One of the main objectives of this project is to understand the seismogenetic behavior of the Alhama de Murcia Fault (FAM) located in the Betic Cordillera (Spain). In this study several intersegment areas were defined. Some structural and paleoseismic studies and geophysical surveys have been carried out on these zones., Research project reference code: CGL2013-47412-C2-1-P, Peer reviewed

The acquired data comprises 2D/3D and 3C components. The acquisition employed 647 seismic receivers, distributed in a 3D mesh around the target and along six 2D crooked lines sampling the study area. The source employed was a 32 t vibroseis truck, operating at c. 900 points in the pathways along the 2D profiles. Each vibration point was used three times, with frequency sweeps of 10-100 Hz., Fair and sustainable production of raw materials is one of the main challenges faced by our society. Through its RawMaterials Programme, the European Institute of Technology (EIT) encourages research and innovation solutions for mineral exploration to make them safer, sustainable and cost-effective. The SIT4ME project, funded by EIT, addresses these objectives by undertaking seismic mineral exploration methods in crystalline tectonic settings, at a reduced cost. The SIT4Me project will analyse the efficiency of passive seismic methods (i.e. ambient noise interferometry) for subsurface imaging, by comparing active- and passive-source datasets in mining areas. The files in this dataset correspond to the controlled-source acquisition., European Institute of Innovation & Technology, Grant number EIT 17024, SIT4ME project, Peer reviewed

The data acquisition contract was awarded to ENRESA and took place in November and December 2013. Seismic data was successfully collected in the Záncara river basin (Cuenca, Spain). The total amount of seismic reflection data collected was 9.7 km in 4 high-resolution seismic reflection profiles E-W oriented. Technical specifications of the profiles: Seismometer: 10 24-channel GEODE ultra-light seismic recordes, Receiver number: 240, Receiver interval: 2 m, Source: accelerated weightdrop 250 kg and 100 kg, Source interval: 6 m, Sample rate: 1 ms, Record time: 4 s. Contact person: Carbonell, R., rcarbo@ictja.csic.es, A high-resolution 2-D seismic reflection survey was acquired to obtain a seismic image of the geological structure of the Záncara river basin (eastern Spain). The study area consists of lutites and gypsum from a Neogene sedimentary sequence. The project also targeted the geometry of the geological structure and the mechanical properties of the underground materials. In addition, this study allowed for an improvement of the geophysical acquisition technics and protocols that provided with a better resolution seismic imaging. Thus, reducing costs and improving the effectiveness of the seismic acquisition., Convenio Colaboración CSIC-ENRESA. Código CSIC: 20133830, Peer reviewed

The data acquisition contract was awarded to ENRESA and took place in January 2014. Seismic data was successfully collected in the Záncara river basin (Cuenca, Spain). This is a high-resolution seismic tomography survey to obtain a full 3-D P-wave seismic velocity image of the studied area. A regular and dense grid of 676 shots and 1200 receivers was used to image a 500 m x 500 m area of the shallow surface. A 240-channel system and a seismic source, consisting of an accelerated weight drop, were used in the acquisition. Half a million travel-time picks were inverted to provide the 3-D seismic velocity distribution up to 120 m depth. The 3-D survey was acquired in five swaths, each one consisting on five receiver lines, resulting in a total of 3380 shot gathers. Technical specifications of the profiles: Receiver number: 240, Receiver interval: 2 m, Source accelerated weightdrop: 250 kg, Source interval: 6 m, Sample rate: 1 ms, Record time: 4 s., In this repository, in addition to the seismic 3DSurvey, a resistivity model (VICANAS_3D_Res_UTM30), a lithological model (VICANAS_3D_Vp_Res_Lito_UTM30), and a training set (VICANAS_Training_set) are available. In order to improve the geological interpretation of the seismic tomography, we integrated it with the resistivity model to build a 3D lithological model. To this aim, we created a new bi-parameter grid with Vp and Res values at each node. Then, we lithologically classified the nodes using supervised learning according to a training set extracted from the wells., A high-resolution seismic tomography survey was acquired to obtain a full 3-D P-wave seismic velocity image of the Záncara river basin (eastern Spain). The study area consists of lutites and gypsum from a Neogene sedimentary sequence. The project also targeted the geometry of the underground structure with emphasis on defining the lithological contacts but also the presence of cavities and faults or fractures. An extensive drilling campaign provided uniquely tight constraints on the lithology; these included core samples and wireline geophysical measurements. The analysis of the well log data enabled the accurate definition of the lithological boundaries and provided an estimate of the seismic velocity ranges associated with each lithology. The final joint interpreted image reveals a wedge-shaped structure consisting of four different lithological units. The study features the necessary key elements to test the travel time tomographic inversion approach for the high-resolution characterization of the shallow surface. In this methodological validation test, travel-time tomography demonstrated to be a powerful tool with a relatively high capacity for imaging in detail the lithological contrasts of evaporitic sequences located at very shallow depths, when integrated with additional geological and geophysical data., Convenio Colaboración CSIC-ENRESA. Código CSIC: 20133830, Peer reviewed

IBERSEIS is a 303 km long deep seismic reflection profile. The transect was recorded in 56 days (from May to July 2001) using a 400 channel SERCEL 388 and five 22 Ton Vibroseis trucks. The asymmetric split spread configuration changed along the profile according to the dips of outcropping structures. To achieve a high resolution at shallow levels and to image steep dips, a 35 m station spacing and a 70 m Vibration Point interval was used with a high fold (60 in average). A relatively long sweep (20 s) was chosen to increase the source energy rather than increasing the number of sweeps per Vibration Point. The migrated and stack dataset derived from this raw data are available in http://hdl.handle.net/10261/220989, IBERSEIS NI: Migrated and stack files: http://dx.doi.org/10.20350/digitalCSIC/12643 ; http://hdl.handle.net/10261/220989, IBERSEIS Normal Incidence (IBERSEIS-NI) is a NE-SW oriented deep seismic reflection profile that provided for the first time a complete section at crustal scale of the Variscan Iberian Massif in the SW of Spain. This seismic profile samples three major tectonic terranes: the South Portuguese Zone, the Ossa-Morena Zone, and the Central Iberian Zone. These terranes show a distinctive seismic signature, as do the sutures separating them. Late strike-slip movements through crustal wedges are apparent in the seismic image and have strongly modified the geometry of sutures. The upper crust appears to be decoupled from the lower crust all along the seismic line, but some deformation has been accommodated at deeper levels. A sill-like structure is imaged in the middle crust as a 1–2 s thick and 175 km long high-amplitude conspicuous reflective band. It is interpreted as a great intrusion of mafic magma in a mid-crustal decollement. Taking into account surface geological data and the revealed crustal architecture, a tectonic evolution is proposed for SW Iberia which includes transpressional collision interacting during Early Carboniferous with a mantle plume. The Moho can be identified along the entire transect as subhorizontal and located at 10 to 11 s, indicating a 30–35 km average crustal thickness. Its seismic signature changes laterally, being very reflective beneath the South Portuguese Zone and the Central Iberian Zone, but discontinuous and diffuse below the Ossa Morena Zone., Comisión Interministerial de Ciencia y Tecnología-Fondo Europeo de Desarrollo Regional (CICYT-FEDER), 1FD1997-2179/RYEN1.-- Junta de Andalucía.-- ENRESA.-- Swedish Research Council.-- Instituto Geológico y Minero de España.-- Spanish Ministry of Science and Technology, BTE2000-0583-C02-01, BTE2000-3035-E, BTE2000-1490-C02-01, Peer reviewed

The wide-angle seismic reflection data set consists of two transects. Transect A coincides with the trace of the IBERSEIS deep seismic reflection profile and transect B is located farther to the SE. The explosive charge was located in a single 20 cm diameter, 50–60-m deep shothole. Explosive shots with charge sizes of 1000, 750 and 500 kg, where distributed along the transect, with the largest charges located at the edges of the profile. 650 digital seismic recorders (590 Texans and 60 3-component Refteks) from IRIS (Incorporated Research Institutions for Seismology) instrument pool where used. These instruments where placed along the 300-km transect A at a 400-m station spacing. For transect B, a denser trace spacing was used. To achieve this, shots were fired twice. The stations were firstly placed at 300–400 m spacing along transect B. Once the shots were fired, the stations were moved 150–200 m toward the north along the profile. All shots were then fired a second time, resulting in shot records with a 150–200 m trace spacing., The IBERSEIS wide-angle seismic reflection dataset consists of two NE-SW oriented transects acquired in the SW of the Iberian Massif. They crossed three major geological zones (South Portuguese Zone, Ossa-Morena Zone, and Central Iberian Zone), with their tectonic contacts and the Pyrite Belt being of greatest interest. The velocity models obtained by forward modeling show a complex crust, especially in the middle crust. The velocity models are the most detailed ones that have been produced in the area and contain a large amount of new features that are relevant to the understanding of the composition of the crust and upper mantle beneath the zone., Spanish Ministry of Science and Innovation, CGL2004-04623, CSD2006-00041.-- Generalitat de Catalunya.-- Junta de Andalucía.--, Peer reviewed

The ALCUDIA transect is a 230 km long, vertical incidence deep seismic reflection profile acquired in 2007. The acquisition parameters, 35 m station spacing, 70 m Vibration Point spacing resulted in a 60-90 fold high resolution seismic reflection image. A 20 s long Vibroseis sweep with frequencies between 8-80 Hz was recorded by a 400 station recording cable and 14 km long split spread configuration., ALCUDIA Normal Incidence (ALCUDIA-NI) is a NE-SW oriented vertical incidence deep seismic reflection transect in the SW of Spain that aimed to image the Variscan Iberian Massif. This transect sampled the Central Iberian Zone and was designed to be the northward continuation of the IBERSEIS-NI seismic profile. The processed image shows a weakly reflective upper crust, a thick, highly reflective and laminated lower crust, and a flat Moho located at 10 s TWTT (30 km depth). The transect can be divided into three segments with different structural styles in the lower crust. In the central segment, the lower crust is imaged by regular, horizontal and parallel reflectors, whereas in the northern and southern segments it displays oblique reflectors interpreted as an important thrust (north) and tectonic wedging involving the mantle (south). The ALCUDIA-NI shows that in an intracontinental orogenic crust, far from the suture zones, the upper and lower crust may react differently to shortening in different sectors, which is taken as evidence for decoupling. The interpreted structures, as deduced from surface geology and the seismic image, show that deformation was distributed homogeneously in the upper crust, whereas it was concentrated in wedge/thrust structures at specific sectors in the lower crust., Spanish Ministry of Science and Innovation, CGL2004-04623/BTE, CSD2006-00041.-- Ministerio de economía y competitividad, CGL2007-63101/BTE.-- Ministerio de economía y competitividad; Fondos Europeos de desarrollo regional (FEDER), CGL2011-24101.-- Junta de Castilla-La Mancha.--, Peer reviewed

The acquisition design included three lines of receivers, having a total length of ca. 350 km. The main line, ALCUDIA-WA, is ca. 310 km long strikes NE-SW to NNE-SSW, it is approximately perpendicular to the structural grain. A 40 km long line of receivers that trends NNW-SSE was deployed perpendicular to the Central System (CS) mountain range. Over 900 TEXANS (single component, digital recording seismic station) from the IRIS-PASSCAL Instrument Pool were deployed from the northern boundary of the Ossa-Morena Zone to the alpine thrust representing the southern boundary of the CS. The entire ALCUDIA-WA survey had a nominal shot and receiver spacing of 70 km and 400m, respectively. Five explosive sources, each one consisting in 1 TM of explosive, were placed in ~55m deep single boreholes, providing a signal rich in high frequencies resulting in shot records characterized by high signal-to-noise ratio. For this reason, these data can be qualified as a high-resolution wide-angle data set., The high-resolution, wide-angle seismic reflection experiment, ALCUDIA-WA, was acquired in 2012 across central Iberia, aiming to constrain the lithospheric structure and resolve the physical properties of the crust and upper mantle. The seismic transect, ca. 310 km long, crossed the Central Iberian Zone from its suture with the Ossa Morena Zone to the southern limit of the Central System mountain range., Spanish Ministry of Science and Innovation, CGL2004-04623/BTE, CGL2007-63101/BTE, CGL2011-24101, CSD2006-00041.--, Peer reviewed