pinecone/core-2020-05-10-deduplication huggingface dataset:
Exhumation of the southern Pyrenean fold-thrust belt (Spain) from orogenic growth to decay

The deformation and exhumation history of an orogen reflects the interactions between tectonic and surface processes. We investigate orogenic wedge deformation, erosion, and sedimentation in the Pyrenees by (a) quantifying the spatiotemporal patterns of exhumation across the southern fold-thrust belt (FTB) with bedrock apatite fission track (AFT) thermochronology and (b) comparing the results with existing deformation, exhumation, and sedimentation chronologies. Eighteen new samples record exhumation during and after orogenesis between 90 and 10 Ma. Rocks from the range core (Axial Zone) record rapid exhumation that progresses east to west and north to south, consistent with patterns of tectonically driven uplift. Synorogenic sediments shed into piggyback basins on the southern fold-thrust belt during mountain building retain a detrital exhumation signal from the Axial Zone. In contrast, samples from other structural positions record exhumation of the thin-skinned Pyrenean thrust sheets, suggesting sediment burial and heating of sufficient magnitudes to reset the AFT system (>∼3 km). In some locations, exhumation of these fold-thrust structures is likely an erosional response to thrust-driven rock uplift. We identify an exhumation phase ∼25-20 Ma that occurs along the central and eastern Spanish Pyrenees at the boundary between thick- and thin-skinned portions of the wedge. We suggest that this distributed exhumation event records (a) a taper response in the southern orogenic wedge to sediment loading and/or (b) a shift to wetter, stormier climate conditions following convergence-driven uplift and full topographic development. A final exhumation phase between ∼20 and 10 Ma may record the excavation of the southern fold-thrust system following base level lowering in the Ebro Basin. © 2013. American Geophysical Union. All Rights Reserved.Financial support was provided by NSF EAR 0724656 to T. Ehlers and a University of Michigan Scott Turner Award in the Earth Sciences to J. Barnes for the fieldworkPeer Reviewe
A seismic geotraverse across the Iberian Variscides: Orogenic shortening, collisional magmatism, and orocline development

A crustal geotraverse through the Iberian Variscides is presented by integrating the available geological and seismic profiling data. Different modes of orogenic shortening are identified, with varying degrees of coupling between upper and lower crust. In northern and southern regions of the geotraverse, a decoupling in the middle crust permits the lower crust to subduct/underthrust, thus compensating for strong upper crustal shortening. This behavior does not result in great crustal thickening, except in sectors of crustal underthrusting. In southern Central Iberia, moderate upper crustal shortening is due to a mechanically strong lower crust impeded to subduct/underthrust. In this region, shortening is partitioned between upper and lower crust, deformation being distributed in the upper crust while localized at major fault zones in the lower crust. Finally, the central region of the geotraverse (northern Central Iberia) shows a coupled crustal deformation, having given way to the largest orogenic thickening in the Iberian Variscides. The thermal maturity of this much thickened crust originated voluminous crustal melting, and concomitant normal-fault detachments developed, while shortening dominated in other regions. Theoretical models suggest that compressive stresses may prevail in the lower crust beneath the extending upper crust, thus explaining the efficient syncollisional exhumation in this part of the orogen. A particular feature of the Iberian Variscan geotraverse is the great importance of out-of-section mass movements, mainly left-lateral shear zones concentrated in two suture boundaries, which displaced to the NW (present coordinates) central and northern Iberia with respect to southern Iberia. © 2013. American Geophysical Union. All Rights Reserved.Funding for this research has been provided by the Spanish Ministry of Science and Innovation (grants: CGL2004-04623/ BTE, CGL2007-63101/BTE, CGL2011-24101, and CSD2006-00041).Peer Reviewe
Deformed Pleistocene marine terraces along the Ionian sea margin of southern Italy: unveiling blind fault-related folds contribution to coastal uplift

Morphotectonic analysis and fault numeric modeling of uplifted marine terraces along the Ionian Sea coast of the Southern Apennines allowed us to place quantitative constraints on middle Pleistocene-Holocene deformation. Ten terrace orders uplifted to as much as +660 m were mapped along ~80 km of the Taranto Gulf coastline. The shorelines document both a regional and a local, fault-induced contribution to uplift. The intermingling between the two deformation sources is attested by three 10 km scale undulations superimposed on a 100 km scale northeastward tilt. The undulations spatially coincide with the trace of NW-SE striking transpressional faults that affected the coastal range during the early Pleistocene. To test whether fault activity continued to the present, we modeled the differential uplift of marine terraces as progressive elastic displacement above blind oblique-thrust ramps seated beneath the coast. Through an iterative and mathematically based procedure, we defined the best geometric and kinematic fault parameters as well as the number and position of fault segments. Fault numerical models predict two fault-propagation folds cored by blind thrusts with slip rates ranging from 0.5 to 0.7 mm/yr and capable of generating an earthquake with a maximum moment magnitude of 5.9–6.3. Notably, we find that the locus of predominant activity has repeatedly shifted between the two fault systems during time and that slip rates on each fault have temporally changed. It is not clear if the active deformation is seismogenic or dominated by aseismic creep; however, the modeled faults are embedded in an offshore transpressional belt that may have sourced historical earthquakes
The north cycladic detachment system and associated mineralization, Mykonos, Greece: Insights on the evolution of the Aegean domain

International audienceIn the Aegean back-arc domain, some 30-35 Ma ago, an increase of the rate of slab retreat led to the initiation of post-orogenic extension, largely accommodated by large-scale structures such as the North Cycladic Detachment System (NCDS). Although this extension is still active nowadays, an E-W compressional regime developed in the Late Miocene with the propagation of the North Anatolian Fault. On Mykonos island (Cyclades), the NE-SW back-arc extension is particularly well expressed with the Livada and Mykonos detachments that belong to the NCDS and that are associated with NW-SE barite veins emplaced during the synkinematic cooling of the Mykonos intrusion. This study shows that the formation of the mineralization occurred when the pluton crossed the ductile-to-brittle transition during its exhumation below the NCDS at ~11-10 Ma. In addition, the kinematics of mineralized structures evolved with time: (1) most of the displacement was accommodated by the top-to-the-NE Livada and Mykonos detachments accompanied by the formation of mineralized normal faults that were (2) reworked in a strike-slip regime with an E-W direction of shortening and a persistent NE-SW stretching and (3) a latepost-mineralization E-W compressional stage with a minor reworking of shallow-dipping faults (locally including the detachments themselves). We interpret this increase of the E-W shortening component recorded during the mineraldeposition as a consequence of the initiation of the westward motion of Anatolia from 10 Ma, thus 4 Ma before the propagation of the North Anatolian Fault in the Dardanelles Strait and the localization of the strain on the Aegean Sea margins
"Arc-continent collision" of the Aleutian-Komandorsky arc into Kamchatka: Insight into Quaternary tectonic segmentation through Pleistocene marine terraces and morphometric analysis of fluvial drainage

At the NW corner of the Pacific region, just south of the Kamchatsky Peninsula, the northern tip of the Pacific plate subduction and associated volcanic arc interacts with the western end of the Aleutian-Komandorsky dextral transform plate boundary and associated arc. Study of both Holocene and Pleistocene sequences of uplifted marine terraces and also of fluvial drainage patterns on the Kamchatsky Peninsula allows us to highlight active tectonics produced by complex plate interaction. Our results show that the central eastern coast of the peninsula is currently divided into four different zones consisting in uplifted blocks associated with various uplift rates in front of a fold-and-thrust zone to the west. Our main tectonic benchmark—the altitude of the shoreline correlated to the Last Interglacial Maximum (Marine Isotopic Stage 5e)—yields late Pleistocene uplift rates ranging from 0.2 to 2.74 mm/yr. One of the main active faults bounding the coastal blocks is dextral and is interpreted as a prolongation of an offshore fault of the Aleutian-Komandorsky dextral transform plate boundary. We suggest that structures on the Kamchatsky Peninsula accommodate a part of the transform motion, but that mainly, the arc-continent collision of the Aleutian arc against Kamchatka produces a “bulldozer” effect on the Kamchatsky Peninsula
Neogene and Quaternary tectonics of the Eastern Sierras Pampeanas, Argentina: Active intraplate deformation inboard of flat-slab subduction

The ranges of the Eastern Sierras Pampeanas are located >600 km east of the Andean  Cordillera in central Argentina and have been interpreted to be a response to shortening  related to flat-slab subduction of the Nazca plate. Uplift of the ranges has been broadly  documented to occur during Neogene time, but many questions remain regarding the timing  and style of deformation, and the subsurface structural configuration. In this study, we  address these unknowns with observations at multiple scales, integrate our results into a  tectonic model for the area, and discuss how our structural interpretation fits with more  regional tectonic models. Our major findings are: (1) The range-bounding faults thrust late  Proterozoic to Cambrian schist and gneiss over poorly dated Pliocene to Pleistocene alluvial  strata. The timing of fault displacement and age of footwall strata suggest that deformation  may have been active at least by Pliocene time. (2) Apatite and zircon (U-Th)/He  thermochronometry exhibits cooling ages that range from Permian to Early Jurassic time  and suggests that rock exhumation in the area is less than 2?3 km since that time. (3)  Deploying a local seismic array allowed for locating seismicity and calculating receiver  functions. These observations indicate that the Moho lies at a depth of 37 km and that a  midcrustal discontinuity appears to correspond to a detachment zone between 15 and 20 km  depth and aligns with a plane of seismicity. In our tectonic model, the craton appears to act  as a rigid backstop to the eastward propagation of stresses from the shallowly subducting  slab. Deformation then propagates back to the west via westward-verging faults along a  midcrustal detachment.Fil: Richardson, T.. Purdue University. Department of Earth and Atmospheric Sciences; Estados UnidosFil: Ridgway, K.. Purdue University. Department of Earth and Atmospheric Sciences; Estados UnidosFil: Gilbert, H.. Purdue University. Department of Earth and Atmospheric Sciences; Estados UnidosFil: Martino, Roberto Donato. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geologia Básica y Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Enkelmann, E.. University of Cincinnati. Department of Geology; Estados UnidosFil: Anderson, M.. Colorado College. Department of Geology; Estados UnidosFil: Alvarado, Patricia Monica. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
The Ainsa Fold and thrust oblique zone of the central Pyrenees: Kinematics of a curved contractional system from paleomagnetic and structural data

Integration of structural, stratigraphic, and paleomagnetic data from the N-S trending structures of the Ainsa Oblique Zone reveals the kinematics of the major thrust salient in the central Pyrenees. These structures experienced clockwise vertical axis rotations that vary from 70° in the east (Mediano anticline) to 55°in the west (Boltaña anticline). Clockwise vertical axis rotations of 60° to 45° occurred from early Lutetian to late Bartonian when the folds and thrusts of the Ainsa Oblique Zone developed. This vertical axis rotation stage resulted from a difference of about 50 km in the amount of displacement on the Gavarnie thrust and an accompanying change in structural style at crustal scale from the central to the western Pyrenees, related to the NE-SW trending pinch out of Triassic evaporites at its basal detachment. A second rotation event of at least 10° took place since Priabonian, as a result of a greater displacement of the Serres Marginals thrust sheet with respect to the Gavarnie thrust sheet above the Upper Eocene-Oligocene salts. The deduced kinematics demonstrates that the orogenic curvature of the central Pyrenees is a progressive curvature resulting from divergent thrust transport direction. Layer parallel shortening mesostructures and kilometer-scale folds also developed by a progressive curvature related to divergent shortening directions during vertical axis rotation. Rotation space problems were solved by along-strike extension which triggered the formation of transverse extensional faults and diapirs at the outer arcs of structural bends. Key Points Progressive curvature, divergent thrust transport direction Along-strike differential shortening by the distribution of weak salt levels Along-strike extension and related diapirism ©2013. American Geophysical Union. All Rights Reserved.This work was funded by the project INTECTOSAL (CGL2010-21968-C02-01) and by the “Grup de Recerca de Geodinàmica i Anàlisi de Conques 2009SGR1198” Secretaria d’Universitat i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya. Josep Poblet acknowledges financial support by research projects: “Geociencias en Iberia: estudios integrados de topografía y evolución 4D [TOPO-IBERIA]” (CSD2006-041) and “Desarrollo de fracturas y venas asociadas al plegamiento [FRAVEPLE]” (CGL2011-23628) funded by Spanish Ministries.Peer Reviewe
Dating brittle tectonic movements with cleft monazite: Fluid-rock interaction and formation of REE minerals

[1] Two millimeter-sized hydrothermal monazites from an open fissure (cleft) that developed late during a dextral transpressional deformation event in the Aar Massif, Switzerland, have been investigated using electron microprobe and ion probe. The monazites are characterized by high Th/U ratios typical of other hydrothermal monazites. Deformation events in the area have been subdivided into three phases: (D1) main thrusting including formation of a new schistosity, (D2) dextral transpression, and (D3) local crenulation including development of a new schistosity. The two younger deformational structures are related to a subvertically oriented intermediate stress axis, which is characteristic for strike slip deformation. The inferred stress environment is consistent with observed kinematics and the opening of such clefts. Therefore, the investigated monazite-bearing cleft formed at the end of D2 and/or D3, and during dextral movements along NNW dipping planes. Interaction of cleft-filling hydrothermal fluid with wall rock results in rare earth element (REE) mineral formation and alteration of the wall rock. The main newly formed REE minerals are Y-Si, Y-Nb-Ti minerals, and monazite. Despite these mineralogical changes, the bulk chemistry of the system remains constant and thus these mineralogical changes require redistribution of elements via a fluid over short distances (centimeter). Low-grade alteration enables local redistribution of REE, related to the stability of the accessory phases. This allows high precision isotope dating of cleft monazite. 232Th/208Pb ages are not affected by excess Pb and yield growth domain ages between 8.03 ± 0.22 and 6.25 ± 0.60 Ma. Monazite crystallization in brittle structures is coeval or younger than 8 Ma zircon fission track data and hence occurred below 280°C
Upper crustal deformation in continent-continent collision: A case study from the Bernard nappe complex (Valais, Switzerland)

The Penninic nappes in the Swiss Alps formed during continental collision between the Adriatic and European plates in Cenozoic times. Although intensely studied, the finite geometry of the basement-bearing Penninic nappes in western Switzerland has remained a matter of debate for decades (e.g., “Siviez-Mischabel dilemma”) and the paleogeographic origin of various nappes has been disputed. Here, we present new structural data for the central part of the Penninic Bernard nappe complex, which contains pre-Permian basement and Permo-Mesozoic metasedimentary units. Our lithological and structural observations indicate that the discrepancy between the different structural models proposed for the Bernard nappe complex can be explained by a lateral discontinuity. In the west, the presence of a Permian graben caused complex isoclinal folding, whereas in the east, the absence of such a graben resulted mainly in imbricate thrusting. The overall geometry of the Bernard nappe complex is the result of three main deformation phases: (1) detachment of Mesozoic cover sediments along Triassic evaporites (Evolène phase) during the early stages of collision, (2) Eocene top-to-the-N(NW) nappe stacking (Anniviers phase), and (3) subsequent backfolding and backshearing (Mischabel phase). The southward localized backshearing is key to understand the structural position and paleogeographic origin of units, such as the Frilihorn and Cimes Blanches “nappes” and the Antrona ophiolites. Based on these observations, we present a new tectonic model for the entire Penninic region of western Switzerland and discuss this model in terms of continental collision zone processes
Torsional vibration characteristics analysis of DFIG-based wind farm and its equivalent model

As large-scale wind farms (WFs) are integrated with the power grid, the interaction between the WF and the grid may excite torsional vibration of the shaft of the wind turbine. To study the shaft's torsional vibration characteristics of a doubly fed induction generator (DFIG)-based WF, a detailed small-signal model of DFIG is established first. Then the small-signal model for a WF composed of multiple DFIGs is developed on the basis of the single-machine model. Modal analysis is employed to investigate the torsional vibration characteristics of a WF made up of several identical DFIGs, whose accuracy is also demonstrated through time-domain simulation. To simplify the torsional vibration analysis for the DFIG-based WF, a reduced-order equivalent model is proposed. The results obtained from modal analysis show that the equivalent model not only precisely maintains all the torsional vibration modes of the original small-signal model but also greatly reduces the computation complexity. With the equivalent model, the 'curse of dimensionality' problem is solved in torsional vibration analysis for large WFs, which is of great help in the design of further damping schemes
Materials in particulate form for tissue engineering. 2 Applications in bone

Materials in particulate form have been the subjects of intensive research in view of their use as
drug delivery systems. While within this application there are still issues to be addressed, these
systems are now being regarded as having a great potential for tissue engineering applications.
Bone repair is a very demanding task, due to the specific characteristics of skeletal tissues, and the
design of scaffolds for bone tissue engineering presents several difficulties. Materials in particulate
form are now seen as a means of achieving higher control over parameters such as porosity, pore
size, surface area and the mechanical properties of the scaffold. These materials also have the
potential to incorporate biologically active molecules for release and to serve as carriers for cells. It
is believed that the combination of these features would create a more efficient approach towards
regeneration. This review focuses on the application ofmaterials in particulate formfor bone tissue
engineering. A brief overview of bone biology and the healing process is also provided in order to
place the application in its broader context. An original compilation of molecules with a documented
role in bone tissue biology is listed, as they have the potential to be used in bone tissue engineering
strategies. To sum up this review, examples of works addressing the above aspects are presented
Chitosan microparticles as injectable scaffolds for tissue engineering

The use of chitosan microparticles as injectable carriers for cell transplantation represents a
promising alternative to avoid the drawbacks of the implantation of other forms of three-dimensional
(3D) scaffolds seeded with cells. In this study, a 3D construct is obtained in vitro by combining
chitosan microparticles crosslinked with genipin and goat bone marrow stromal cells (GBMCs). Cell
viability and the morphology of GBMCs were evaluated after culture for 7 and 14 days. Our results
show the feasibility of chitosan microparticles as potential injectable scaffolds for tissue engineering
and regenerative medicine.Support from the Generalitat Valenciana through a short-term fellowship (No. BEFPI/2007/012) is kindly acknowledged. D.M.G.C. and J.L.G.R. acknowledge the support of the Spanish Ministry of Science through Project No. MAT2007-66759-C03-01 (including FEDER financial support). This work was also partially supported by the European Union-funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758), and the European NoE EXPERTISSUES (NMP3-CT-2004-500283)
Hierarchical starch-based fibrous scaffold for bone tissue engineering applications

Fibrous structures mimicking the morphology of the natural extracellular matrix are considered promising scaffolds for tissue engineering. This work aims to develop a novel hierarchical starch-based scaffold. Such scaffolds were obtained by a combination of starch-polycaprolactone micro- and polycaprolactone nano-motifs, respectively produced by rapid prototyping (RP) and electrospinning techniques. Scanning electron microscopy (SEM) and micro-computed tomography analysis showed the successful fabrication of a multilayer scaffold composed of parallel aligned microfibres in a grid-like arrangement, intercalated by a mesh-like structure with randomly distributed nanofibres (NFM). Human osteoblast-like cells were dynamically seeded on the scaffolds, using spinner flasks, and cultured for 7 days under static conditions. SEM analysis showed predominant cell attachment and spreading on the nanofibre meshes, which enhanced cell retention at the bulk of the composed/hierarchical scaffolds. A significant increment in cell proliferation and osteoblastic activity, assessed by alkaline phosphatase quantification, was observed on the hierarchical fibrous scaffolds. These results support our hypothesis that the integration of nanoscale fibres into 3D rapid prototype scaffolds substantially improves their biological performance in bone tissue-engineering strategies.This work was partially supported by the European Integrated Project GENOSTEM (Grant No. LSH-STREP-CT-2003-503161) and the European Network of Excellence EXPERTISSUES (Grant No. NMP3-CT-2004-500283). We also acknowledge the Portuguese Foundation for Science and Technology for the project Naturally Nano (Grant No. POCI/EME/58982/2004) and a PhD grant to A. Martins (Grant No. SFRH/BD/24382/2005)