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High-pressure and ultrahigh-pressure metamorphic rocks have been collected from three districts located in the Tien-Shan Mountains, Kyrghyzstan: the Aktyuz, Atbashy and Makbal districts. All of them have suffered high-pressure metamorphism, and one of them, has experienced ultrahigh-pressure conditions. Chemical compositions of the constituent minerals from the metamorphic rocks in these localities are provided in this paper.13

Geologia Lurra aztertzen duen zientzia da: lurraren osaera, egitura eta jatorria, eta bai arroketan aztarnak utzi dituzten iraganeko edo gaur egungo gertaerak ere. Baina, zergatik du gizarteak geologoen beharra? Hona hemen zenbait arrazoi: - Geologoek lurrazalari eta lurpeari buruzko informazioa bildu, eta interpretatu egiten dute. Informazio horrek guztiak ahalbidetzen du planetaren iraganeko historia, Lurrean aurreikus daitezkeen aldaketak eta gure planetak Eguzki-sistemarekin duen harremana finkatzea. - Gizarteak beharrezkoak ditu baliabide naturalak (metalikoak, ez-metalikoak, ura eta erregai fosilak). Geologoen parte-hartzea erabakigarria da hobi berriak aurkitzeko eta ingurumena zaintzen duten baliabide naturalen ustiapen eta kudeaketarako irizpideak ezartzeko. - Kartografia geologikoen bidez arrisku-eremuak identifikatu eta lurzoruaren erabilerak mugatzen dira. Geologoak beharrezkoak dira, beraz, lurraldearen planifikaziorako eta garapen iraunkorrerako estrategiak garatzeko. - Geologiaren ezagutzak eta informazio geologikoaren erabilera egokiak laguntzen dute bizitzak salbatzen eta lurrikarak, tsunamiak, erupzio bolkanikoak, uholdeak eta lurjausiak bezalako katastrofe naturalek eragindako diru-galerak murrizten. Halaber laguntzen dute eraikuntza-proiektuak, herri-lanak eta abar garatzen ere. Proposatutako jardueren bitartez, Zientzia Geologikoen adar desberdinen oinarrizko zenbait alderdi ezagutzera eman nahi ditugu. Horretarako, lau saio antolatu ditugu Paleontologia, Mineralogia, Petrologia eta Tektonika arloetan murgiltzeko.

Geology is the science that studies the Earth, its composition, structure and origin in addition to past and present phenomena that leave their mark on rocks. So why does society need geologists? Some of the main reasons are listed below: - Geologists compile and interpret information about the earth’s surface and subsoil, which allows us to establish the planet’s past history, any foreseeable changes and its relationship with the rest of the solar system. - Society needs natural resources (metals, non-metals, water and fossil fuels) to survive. The work of geologists is therefore a key part of finding new deposits and establishing a guide for exploring and managing resources in an environmentally-friendly way. - The creation of geological maps allows us to identify potential risk areas and survey different land uses; in other words, they make an essential contribution to land planning and proposing sustainable development strategies in a region. - Learning about Geology and the proper use of geological information contributes to saving lives and reducing financial loss caused by natural catastrophes such as earthquakes, tsunamis, volcanic eruptions, flooding and landslides, while also helping to develop construction projects, public works, etc. Through the proposed activities we aim to explain some of the basic elements of the different specialities within the field of Geological Sciences. In order to do this, four sessions have been organised that will allow for a quick insight into the fields of Palaeontology, Mineralogy, Petrology and Tectonics.

Geology is the science that studies the Earth, its composition, structure and origin in addition to past and present phenomena that leave their mark on rocks. So why does society need geologists? Some of the main reasons are listed below: - Geologists compile and interpret information about the earth’s surface and subsoil, which allows us to establish the planet’s past history, any foreseeable changes and its relationship with the rest of the solar system. - Society needs natural resources (metals, non-metals, water and fossil fuels) to survive. The work of geologists is therefore a key part of finding new deposits and establishing a guide for exploring and managing resources in an environmentally-friendly way. - The creation of geological maps allows us to identify potential risk areas and survey different land uses; in other words, they make an essential contribution to land planning and proposing sustainable development strategies in a region. - Learning about Geology and the proper use of geological information contributes to saving lives and reducing financial loss caused by natural catastrophes such as earthquakes, tsunamis, volcanic eruptions, flooding and landslides, while also helping to develop construction projects, public works, etc. Through the proposed activities we aim to explain some of the basic elements of the different specialities within the field of Geological Sciences. In order to do this, four sessions have been organised that will allow for a quick insight into the fields of Palaeontology, Mineralogy, Petrology and Tectonics.

La Geología es la ciencia que estudia la Tierra en su conjunto, su composición, estructura y origen, así como los fenómenos que han tenido lugar en el pasado o que se producen en la actualidad y que han dejado sus huellas en las rocas. Pero, ¿por qué necesita la sociedad a los geólogos? A continuación se citan algunas de las principales razones: - Los geólogos recopilan e interpretan información de la superficie terrestre y del subsuelo, lo que permite establecer la historia pasada del planeta, sus cambios previsibles y su relación con el resto del sistema solar. - La sociedad requiere para su subsistencia recursos naturales (metálicos, no metálicos, hídricos y combustibles fósiles). La labor de los geólogos es determinante para la localización de nuevos yacimientos y para establecer las guías de una explotación y gestión respetuosa con el medio ambiente. - La elaboración de cartografías geológicas permite identificar potenciales zonas de riesgo y acotar distintos usos del suelo; es decir, es esencial para la planificación del territorio y para proponer estrategias de desarrollo sostenible en una región. - La educación en Geología y el buen uso de la información geológica contribuye a salvar vidas y a reducir las pérdidas económicas originadas por catástrofes naturales tales como terremotos, tsunamis, erupciones volcánicas, inundaciones y desprendimientos, así como a desarrollar proyectos de construcción, obras públicas, etc. Con las actividades propuestas se pretende dar a conocer algunos aspectos básicos de distintas especialidades de las Ciencias Geológicas. Para ello se han organizado cuatro sesiones destinadas a realizar una pequeña inmersión en el campo de la Paleontología, la Mineralogía, la Petrología y la Tectónica.

High-pressure granulitic tectonites from shear zones at the contacts between the Bacariza Formation and its bounding units developed after eo-Hercynian subduction, during the initial exhumation of the Cabo Ortegal complex. Structural, petrographic, and crystallographic analysis of these tectonites with the EBSD technique enables us to unravel different, syn-metamorphic, deformation mechanisms in the minerals of the high-pressure granulitic assemblage. Dislocation creep and recovery were the main deformation mechanisms in garnet during peak metamorphism, followed by porphyroclast rigid rotation. The matrix minerals accommodated subsequent ductile deformation, still under high-pressure. Mass transfer, anisotropic growth and dislocation creep dominated deformation of augite. Subgrain rotation-recrystallisation by climbaccommodated dislocation creep operated in plagioclase and dislocation creep by prism-slip in quartz. Subsequent, static amphibolite-facies retrogradation was followed by decompression-related microfracturing during exhumation through medium- to upper crustal realms. Ductile rock deformation was non-coaxial and accommodated a top-to-the-NE displacement of hangingwall blocks

High-pressure granulitic tectonites from shear zones at the contacts between the Bacariza Formation and its bounding units developed after eo-Hercynian subduction, during the initial exhumation of the Cabo Ortegal complex. Structural, petrographic, and crystallographic analysis of these tectonites with the EBSD technique enables us to unravel different, syn-metamorphic, deformation mechanisms in the minerals of the high-pressure granulitic assemblage. Dislocation creep and recovery were the main deformation mechanisms in garnet during peak metamorphism, followed by porphyroclast rigid rotation. The matrix minerals accommodated subsequent ductile deformation, still under high-pressure. Mass transfer, anisotropic growth and dislocation creep dominated deformation of augite. Subgrain rotation-recrystallisation by climbaccommodated dislocation creep operated in plagioclase and dislocation creep by prism-slip in quartz. Subsequent, static amphibolite-facies retrogradation was followed by decompression-related microfracturing during exhumation through medium- to upper crustal realms. Ductile rock deformation was non-coaxial and accommodated a top-to-the-NE displacement of hangingwall blocks

Occurrence of tectonites with features characteristic of both pseudotachylytes and ultramylonites formed under high-pressure granulite-facies conditions is reported in the Cabo Ortegal Complex of NW Spain. We interpret that these rocks were originated due to a seismic event at great depth (1.4 GPa) under high temperatures (740 ºC). Shear heating would have affected the still hot and mechanically rigid granulites and provoked melt formation. Ambient high P and T would have led to subsequent recrystallization of the previously formed melt giving rise to a weak planar fabric

Occurrence of tectonites with features characteristic of both pseudotachylytes and ultramylonites formed under high-pressure granulite-facies conditions is reported in the Cabo Ortegal Complex of NW Spain. We interpret that these rocks were originated due to a seismic event at great depth (1.4 GPa) under high temperatures (740 ºC). Shear heating would have affected the still hot and mechanically rigid granulites and provoked melt formation. Ambient high P and T would have led to subsequent recrystallization of the previously formed melt giving rise to a weak planar fabric

High-pressure volcanic-arc granulites, N-MORB eclogites and shallow crustal volcanosedimentary high-pressure gneiss units occur in the high-pressure metamorphic fold-nappes and ductile thrusts that make up the Cabo Ortegal upper allochthons. Confluence of units from such disparate tectonic settings occurred at an eo-Hercynian convergent plate margin, that in this case, involved oceanic, arc and continental lithosphere. We argue that the sheath-like form of the fold nappes and the mineral and stretching lineations defined by high-pressure mineral assemblages subparallel to fold axes depict the internal organization of high-pressure sheets at deep tectonic realms of an oblique subduction/collision orogenic channel

High-pressure volcanic-arc granulites, N-MORB eclogites and shallow crustal volcanosedimentary high-pressure gneiss units occur in the high-pressure metamorphic fold-nappes and ductile thrusts that make up the Cabo Ortegal upper allochthons. Confluence of units from such disparate tectonic settings occurred at an eo-Hercynian convergent plate margin, that in this case, involved oceanic, arc and continental lithosphere. We argue that the sheath-like form of the fold nappes and the mineral and stretching lineations defined by high-pressure mineral assemblages subparallel to fold axes depict the internal organization of high-pressure sheets at deep tectonic realms of an oblique subduction/collision orogenic channel

Heterogeneous ductile deformation occurred in the Bacariza formation coeval with hercynian high-pressure granulite facies metamorphism. Eye and anvil fold structures in YZ structural sections have been identified in several outcrops as well as on the map scale. They are interpreted as lineation-perpendicular sections of sheath folds. The mapped foliation trajectory closures produce a variety of geometries defining dome, saddle, basin and inverted saddle configurations, likely related to culminations and depressions of secondary sheath folds within a major one. These sheath-like folded structures might be considered as natural examples of heterogeneous shear in deep subduction/collision channels

Heterogeneous ductile deformation occurred in the Bacariza formation coeval with hercynian high-pressure granulite facies metamorphism. Eye and anvil fold structures in YZ structural sections have been identified in several outcrops as well as on the map scale. They are interpreted as lineation-perpendicular sections of sheath folds. The mapped foliation trajectory closures produce a variety of geometries defining dome, saddle, basin and inverted saddle configurations, likely related to culminations and depressions of secondary sheath folds within a major one. These sheath-like folded structures might be considered as natural examples of heterogeneous shear in deep subduction/collision channels

[EUS] Lan honetan Chimparra Gneisak izeneko milonitak aztertuko dira, gradu eta presio altuko metamorfismoa jasan duten jatorri bolkanosedimentariodun arrokak. Bilatzen den xede nagusia Chimparra Gneisen petrologia eta mikroegiturak deskribatzea da; alde batetik, deformazio faseak ezberdintzeko eta arrokak jasandako presio eta tenperatura baldintzak ezagutzeko, eta bestetik, milonitizazio faseari buruzko informazioa lortzeko: mineralen orientazio preferenteak bilatzea, mineral ezberdinek kristal barneko deformazioan aktibatutako irristatze-mekanismoak ezagutzea eta lineazio eta zizaila motak argitzea. Horretarako, landa eta laborategi lana egin izan da, ikerketa bibliografikoaz gain. Mikroskopio optikoan azterketa petrologikoa burutu, eta EBSD teknika berria erabili da datu petrologiko osagarriak eta datu mikroestrukturalak lortzeko.