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U-Pb dating and geochemical analyzes (δ18O, δ13C, Δ47, 87Sr/86Sr and elemental composition) have been applied to fracture-filling calcite veins and host carbonates from the Bóixols-Sant Corneli anticline, which developed along the front of the Bóixols thrust sheet in the Southern Pyrenees. This robust dataset is used to determine: (i) the absolute timing of fracturing and mineralization from fluid flow; (ii) the age and duration of fold evolution; and (iii) the variations and implications of fluid behavior across the anticline, as has been described in the article “Spatio-temporal variation of fluid flow behavior along a fold: The Bóixols-Sant Corneli anticline (Southern Pyrenees) from U–Pb dating and structural, petrographic, and geochemical constraints – Marine and Petroleum Geology (2022) (Muñoz-López et al., 2022). In this new contribution, we present the raw data that have been analyzed and discussed in the related research article and, also, the whole elemental and REE composition of calcite veins and host carbonates that has not been published yet. These data may be used to unravel the age and origin of veins, to understand their sequential evolution in orogenic belts and to compare our results with those obtained in similar settings worldwide., This is a contribution to the DGICYT Spanish projects PGC2018-093903-B-C22 and PID2021-122467NB-C22 (Ministerio de Ciencia, Innovación y Universidades/Agencia Estatal de Investigación /10.13039/501100011033/ Fondo Europeo de Desarrollo Regional, Unión Europea), the Grup Consolidat de Recerca “Geologia Sedimentària” (2017-SGR-824) and the Grup Consolidat de Recerca “Modelització Geodinàmica de la Litosfera” (2017SGR-847). This work was also partially funded by ALORBE project (PIE–CSIC–202030E310).

X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - Gasteiz, Calcite veins precipitated in the Estamariu thrust during two tectonic events have been investigated in order to decipher the relationships between deformation and fluid migration in Paleozoic basement rocks. Structural observations constrain the timing of vein formation and fluid migration, whilst geochemical analyses (¿13C, ¿18O, 87Sr/86Sr and elemental composition) of the related calcite cements indicate the fluid origin, pathways and extent of fluid-rock interaction. The first tectonic event, related to the Alpine reactivation of the Estamariu Variscan thrust, is characterized by the upward migration of fluids derived from the crystalline basement, giving rise to the precipitation of calcite cements Cc1 and Cc2. The second tectonic event, developed during the Neogene extension, was responsible of the reactivation of the Estamariu thrust and the development of normal faults and shear fractures in which calcite cements Cc3, Cc4 and Cc5 precipitated. Cc3 and Cc4 precipitated from meteoric fluids that interacted at depth with basement rocks before upflowing through fault zones and related structures. Cc5 precipitated from meteoric fluids percolating from the surface through small fractures., This research was funded by the Spanish Projects CGL2015-66335-C2-1-R and PGC2018-093903-B-C22, and by the Grup Consolidat de Recerca “Geologia Sedimentària” (2017-SGR- 824). The PhD research of DM-L is supported by the FPI2016 (BES-2016-077214) Spanish program from MINECO.

International Ocean Discovery Program Expeditions 352 and 351 drilled into the Western Pacific Izu‐Bonin forearc and rear arc. The drill cores revealed that the forearc is composed of forearc basalts (FAB) and boninites and the rear arc consists of FAB‐like rocks. These rocks are pervaded by calcite veins. Blocky vein microtextures enclosing host rock fragments dominate in all locations and suggest hydrofracturing and advective fluid flow. Significant diffusion‐fed and crystallization pressure‐driven antitaxial veining is restricted to the rear arc. The lack of faults and presence of an Eocene sedimentary cover in the rear arc facilitated antitaxial veining. Rare earth element and isotopic (δ18O, δ13C, 87Sr/86Sr, and Δ47) tracers indicate varying parental fluid compositions ranging from pristine to variably modified seawater. The most pristine seawater signatures are recorded by FAB‐hosted low‐T (95% seawater and, Geochemistry, Geophysics, Geosystems, 21 (2), ISSN:1525-2027

The extensional Val Roveto Fault, which is the longest exhumed potentially-seismogenic structure of central Apennines, Italy, is examined to constrain earthquake-related fluid circulation and fluid sources within shallow carbonate-hosted faults. The study focuses on fault-related comb and slip-parallel veins that are calcite-filled and cut through the principal surface of the Val Roveto Fault. We observe multiple crack-and-seal events characterized by several veining episodes, probably related to different slip increments along the fault plane. We show that vein calcite precipitated in Late Pleistocene time below the present-day outcrop level at a maximum depth of similar to 350 m and temperatures between 32 and 64 degrees C from meteoric-derived fluids modified by reactions with crustal rocks and with a mantle contribution (up to similar to 39%). The observed warm temperatures are not compatible with a shallow (

L’evoluzione a lungo termine dei prismi di accrezione è caratterizzata da interazioni complesse tra tettonica, forze di volume gravitazionali, e processi superficiali. E' influenzata da cambiamenti delle condizioni geodinamiche a grande scala, della configurazione geometrica dei margini di placca convergenti, delle proprietà meccaniche dei materiali coinvolti nella deformazione, e delle condizioni climatiche. In questo contesto, deformazioni contrazionali ed estensionali possono coesistere in porzioni diverse di uno stesso prisma o interessare ciclicamente la stessa area. Pulsi estensionali sviluppati durante la storia orogenica contrazionale di prismi di accrezione, in particolare, sono stati documentati in numerosi contesti e previsti dai modelli geo-meccanici. Le strutture deformative associate a tali pulsi estensionali contribuiscono all’evoluzione a scala regionale degli orogeni, influenzando la circolazione dei fluidi nella crosta superiore e modificando le proprietà meccaniche dei prismi di accrezione. I pulsi estensionali sin-contrazionali hanno perciò una notevole importanza scientifica ed economica. Nell’ambito di questa Tesi di Dottorato vengono investigate strutture deformative sviluppate durante la storia orogenica contrazionale di due prismi di accrezione: le Montagne dell'Oman e l'Appennino Settentrionale. Le attività di ricerca sono caratterizzate da un approccio multidisciplinare; l'evoluzione paleoidrologica delle strutture e i loro effetti sulla circolazione dei fluidi nella crosta superiore sono investigati con particolare attenzione. Il caso di studio di Jabal Qusaybah (Oman) offre la possibilità di studiare una struttura anticlinale sviluppata a livelli strutturali superficiali, al fronte del cuneo tettonico. Nonostante la sua posizione strutturale, l'evoluzione della piega è caratterizzata da interazioni tra deformazioni contrazionali, estensionali, e trascorrenti. I casi di studio nell'Appennino Settentrionale comprendono strutture estensionali chilometriche associate all'evoluzione di interi settori del prisma. Nel caso della Val di Lima, un sistema di faglie estensionali a basso angolo è univocamente inquadrato in un contesto contrazionale, essendo coinvolto in un piegamento successivo associato a sovrascorrimenti fuori sequenza. Nel caso di studio di Tellaro, il sistema di faglie estensionali taglia l'anticlinale di Punta Bianca, essendo associato all'assottigliamento tardo-orogenico del settore interno del prisma Appenninico. Il caso di Studio della Lunigiana include entrambi gli scenari precedenti. The long term evolution of orogenic wedges is characterized by complex interactions between tectonics, gravitational body forces, and surface processes. It is influenced by changes of large-scale geodynamic conditions, geometrical configuration of plate margins, mechanical properties of the materials involved in the deformation, and climate conditions. Within this framework, contractional and extensional deformations may coexist in different sectors of a thrust wedge or cyclically affect the same area. In particular, extensional pulses developed during the contractional orogenic history of thrust wedges have been documented in various contexts and predicted by geo-mechanical models. Deformation structures associated with such extensional events contribute to the regional-scale evolution of orogens, influencing fluid circulation within the upper crust and modifying mechanical properties of thrust wedges. Therefore, sin-contractional extension have remarkable scientific and economic significance. This Ph.D. thesis investigates extensional deformation structures developed during the orogenic contractional history of two thrust wedges: the Oman Mountains and the Northern Apennines. Research is done with a multidisciplinary approach, and close attention is paid to the palaehydrological evolution of the deformation structures and their influence on fluid circulation through the upper crust. The case study of the Jabal Qusaybah (Oman) allows investigating on an anticline developed at shallow structural levels, at the front of a thrust wedge. Despite this structural position, the evolution of the fold is characterized by interactions between contractional, extensional, and left-lateral strike-slip deformations. The Northern Apennines case studies involve km-scale extensional structures associated with the evolution of entire wedge sectors. In the Val di Lima case, a low-angle extensional fault system is unequivocally framed within the contractional orogenic history, being affected by superimposed folding due to out-of-sequence thrusting. In the Tellaro case, the extensional fault system cuts through the Punta Bianca anticline, being likely associated with the late orogenic thinning of the internal sector of the Northern Apennines. The Lunigiana case includes both the previous scenarios.