The geological cartographies available are, in general, of good quality, particularly in the Dominican Republic (result of SYSMIN-I and II), which avoids the significant investment of technical and economic resources that entails obtaining them. However, small-scale maps will be necessary in the Bonao-La Vega and Jarabacoa sectors to establish the basic lithological, structural and petrological relationships for subsequent analytical and modelling studies. The structural study of the mineralization and its host unit is critical in the exploration of mineral deposits. Therefore, it is essential in the field-work stage to define a sequence of deformation phases (D1, D2, D3...) and related metamorphic stages (M1, M2, M3...), in order to frame the recognized mineralization events. The P-T conditions, heterogeneity, pervasively, coaxiality or non-coaxiality, etc. of each deformation phases will control the spatial distribution of mineralization.

The research team already has a considerable collection of samples to study, mainly from field campaigns carried out by the research team and work group in previous projects. However, sampling will be aimed to the resolution of the objectives of this project and will be intensive in areas selected for detailed mapping. Associated with the geological-structural mapping, radiolarites will be sampled for biostratigraphic dating, which will allow establishing the origin and provenance of some oceanic igneous terranes.
Field-work campaigns will be organized together for both Subprojects, if posssible. In the first year of the project, campaigns will be carried out in central and western Cuba (20 days) and in the Bonao-Villa Altagracia region of the Dominican Republic (15 days). In the second year, a field campaign will be carried out in eastern Cuba (20 days) and another in the La Vega-Jarabacoa region of the Dominican Republic (15 days).

These activities will be mainly conducted in the Laboratories of the Department of Mineralogy, Petrology and Applied Geology of the University of Barcelona, the Department of Mineralogy and Petrology of the University of Granada, the Department of Geology of University of Oviedo and the IGME Analytical and Mineralurgical Laboratories in Tres Cantos, Madrid. Hydroseparation is a very suitable technique for the separation of heavy minerals in the fine fraction (zircon, platinum group minerals, native gold, electrum, etc.), proving to be currently the most efficient method for grains <100 microns in size. By means of this technique, zircons even <50 microns in size have been separated in ophiolitic chromitites (Proenza et al., 2018. Geoscience Frontiers. https://doi.org/10.1016/j.gsf.2017.12.005)

These activities will be mainly conducted in the Laboratories of the Department of Mineralogy, Petrology and Applied Geology of the University of Barcelona, the Department of Mineralogy and Petrology of the University of Granada, the Department of Geology of University of Oviedo and the IGME Analytical and Mineralurgical Laboratories in Tres Cantos, Madrid. Hydroseparation is a very suitable technique for the separation of heavy minerals in the fine fraction (zircon, platinum group minerals, native gold, electrum, etc.), proving to be currently the most efficient method for grains <100 microns in size. By means of this technique, zircons even <50 microns in size have been separated in ophiolitic chromitites (Proenza et al., 2018. Geoscience Frontiers. https://doi.org/10.1016/j.gsf.2017.12.005)

These activities will be mainly conducted in the Laboratories of the Department of Mineralogy, Petrology and Applied Geology of the University of Barcelona, the Department of Mineralogy and Petrology of the University of Granada, the Department of Geology of University of Oviedo and the IGME Analytical and Mineralurgical Laboratories in Tres Cantos, Madrid. Hydroseparation is a very suitable technique for the separation of heavy minerals in the fine fraction (zircon, platinum group minerals, native gold, electrum, etc.), proving to be currently the most efficient method for grains <100 microns in size. By means of this technique, zircons even <50 microns in size have been separated in ophiolitic chromitites (Proenza et al., 2018. Geoscience Frontiers. https://doi.org/10.1016/j.gsf.2017.12.005)

The methodology in the geological-structural studies consists in applying various thematic mapping techniques, the realization of balanced and compensated geological cross-sections and the structural analysis at the macro, meso and microscale. The research team is a pioneer in the use of digital technologies under GIS platform in 2-D and 3-D for field data collection, thematic mapping and visualization of mineral structures and deposits. Software to use is ArcGIS v10.6 and ArcGIS-Pro, MOVE2018, FieldMove Clino, ArcPad v10.4 and Geocollector, RockWorks16 (Rockware) and own IGME developments (INGEOTAB and Caderneta Digital de Geologia App-QGIS, PLANAGEO-IGME Angola). The great advantage of this methodology is the storage in spatial databases of all geological information obtained in the field in a georeferenced way and the ease of integrating the results for modelling and visualization techniques. Also the possibility of being able to consult previous geophysical and geochemical data during fieldwork and the ease of a rapid change of scale in its graphic representation.

Among the techniques of structural analysis, the geometric and kinematic analysis of structures, the dynamic analysis of meso and microstructures, the determination of the amounts of displacement and the construction of rigorous geological cross-sections will be used. The geometric and dynamic analysis of mesostructures will be carried out with the RockWorks16 (Rockware), FaultKin 7.4, TectonicsVB, Win-Tensor and T-TECTOX5 programs. SSPX software (Cardozo and Allmendinger, 2008) will be used to calculate the deformation from displacement/velocity data in 2-D/3-D.
The Caribbean accretion-collision complex segment outcropping in the Dominican Republic is deformed by an important syn- to post-collisional strike-slip tectonics. Therefore, structural studies must be performed in 3-D. The representation and interpretation of the aeromagnetic and radiometric data of the SYSMIN project is of great utility in this study. This methodology has already been applied in previous projects and it is essential to visualize structures in areas covered by dense vegetation or under a recent sedimentary cover, as well as for the location and definition of mineral deposits. The large number of laboratory measurements of physical properties in rock samples already made (>1000), establishes an optimal situation for obtaining accurate 2-D and 3-D geological-structural models. The software to be used is OASIS 7.5 and RockWorks16. Eventually, additional samples will be taken to determine the magnetic susceptibility of lithological and mineralization types with little or no coverage in the rock database.

Quantitative microstructural analysis is used in oriented rock samples for the discrimination of mineral phases at the microscale, morphological characterization of grains, and measurement of the preferred crystallographic orientation of constituent minerals. The combined study of these microstructural data with field geological observations provides information on the P-T conditions of deformation, deformation mechanisms involved, orientation of the paleostress field, and its kinematics. Obtaining this information from representative samples allows for the extrapolation of ductile deformation flow paths from the micro- and mesoscale to the regional scale, which is crucial for elucidating the kinematics and dynamics of a specific geological-structural unit. The application of this methodology to deformed peridotites has allowed for the understanding of mantle dynamics in orogenic processes (Hidas et al., 2013, 2016).

In quantitative microstructural analysis, electron backscattered diffraction (EBSD) coupled to a scanning electron microscope (SEM) is used. Combining EBSD and micro-computerized tomography (µ-CT) results allow to reconstruct the microstructure in 3-D following the method of Kahl et al. (2017). EBSD provides morphological and preferential orientation information of the mineral grain network, while µ-CT provides data on their volumetric shape and distribution. Known the orientation of the mineral foliation and lineation in samples of deformed rocks, this combined methodology provides additional information on the orientation of the flow and the conditions of the deformation (Hidas et al., 2016; Dilissen et al., 2018). In parallel, in situ data of the mineral-chemistry and isotopic composition of phases of interest will be obtained in representative rock samples, using the XRD, EMPA, LA-ICP-MS and SIMS techniques. These studies are aimed at determining the tectono-magmatic and tectono-metamorphic evolution of the geological units that contain mineral deposits.

Geochronological studies will be aimed to obtain the absolute age of crystallization or cooling of magmatic bodies and dikes, or veins of metamorphic segregation, coeval to (or syn-tectonically intruded to) mineralization. TIMS equipment of the IGME Laboratories allows the U-Pb dating of zircon, monacite, xenotime, titanite and rutile by isotopic dilution and with high analytical precision. In addition our collaboration with Dr. Beranoaguirre (UPV Bilbao/ Geozentrum Frankfurt) will allow access to MC-ICPMS instrumentation for Lu-Hf dating. 40Ar/39Ar geochronology of amphibole, feldspar and micas will be performed with a mass spectrometer equipped with an electronic ion-count multiplier at the University of British Columbia (Vancouver, Canada), where the research team maintains a collaboration of more than 15 years.

The methodology to be used in this activity is to improve the global geodynamic model developed under ArcGIS platform for the last 600 Ma by Dr. Stampfli group of the University of Lausanne (https://www.unil.ch/iste/en/home/menuinst/recherche/geology-and-geodynamics-of-mountain-belts/ gerard-stampfli.html), with which there are collaborations for the Central American-Caribbean region main in several stays at UNIL by the IP. Techniques and definitions of the model are described by Stampfli and Borel (2002, 2004), Hochard (2008) and Stampfli et al. (2012). Revision of the global model with the geological-structural constraints obtained in the project will allow its updating and the realization of detailed and physically consistent geodynamic reconstructions, where the formation of the mineral systems can be properly introduced.

The methodology consists of an implicit geometric modeling in 2-D and 3-D of the distribution of lithologies, tectonic structures, mineralized bodies and other secondary data (geophysical and geochemical), which allow the precise definition of the mineral deposit and reveal its structural control. Mainly, the software to use is RockWorks16 (Rockware) and Adds for OASIS 7.5. Kinematic and dynamic boundary conditions can also be applied to the geometry, which allow the evaluation of properties in the rock volume such as stress distribution, mechanical behavior, flow of fluids or melts, temperature or permeability. These numerical modelling techniques at different scales allow us to deduce the physical-chemical conditions that control the formation of mineral systems. For the visco-elasto-plastic numerical modeling in 2-D of simplified geodynamic processes (lithospheric extension, arc-continent collision, break-off of the subducted slab, deformation in the accretionary prism, etc.), MATLAB codes proposed by the Gerya group and collaborators (Gerya, 2010, 2019; and references herein) will be used.

Milestones consist of the publication and transfer of the results of the project.

Milestones consist of the publication and transfer of the results of the project.