A substantial quantity of ballast, primarily comprising blocks and pebbles of limestones and quartzose limestones, has been recovered in Parzine Bay (Ilovik Island, Croatia) in the stern section of a sailing vessel discovered in 2016, that wrecked between the second and the third quarter of the 2nd C. BC. This research introduces an integrated methodology for investigating the provenance of ballast stones. Both the skeletal assemblages and the siliciclastic content of the rocks suggest a common source for most of the ballast. Micropalaeontological analyses (benthic and planktic foraminifera) and Sr-87/Sr-86 values indicate an age younger than 500 ka. Three main lithologies dominate the ballast rock assemblage: 1) tightly cemented quartzose grainstones and quartzarenites, 2) bioclastic quartzose grainstone with large mollusks and rhodoliths and 3) weakly indurated and bioturbated quartzose grainstone. An extensive field survey and samples analysis conducted in the Quaternary mixed carbonate-siliciclastic successions along the Adriatic and Ionian coast of Italy, reveal a very high degree of similarity between the ballast stones and the Middle to Upper Pleistocene terrace deposits of the region of Brindisi (Apulia, Italy). These similarities encompass palaeontological assemblages, age, lithofacies and microfacies associations, mineralogical composition, quartz grain morphology, sedimentary and diagenetic features, stable carbon and oxygen isotope compositions, as well as the morphology and alteration features of pebbles. Given the uniformity of the ballast of the Romano-Republican Ilovik-Parzine 1 wreck, the study suggests, with a reasonable degree of certainty, that it was loaded in a single operation near Brundisium, one of the major ports of the Apulian coast (Italy). The results also suggest two additional hypotheses: 1) the ballast could have served as permanent ballast transported to balance the ship after it was launched; 2) the provenance of the ballast may provide insights into the location where the ship was constructed.

An integrated approach combining petrography, photogrammetry, geochronology, SEM, and geochemical data was utilized to analyze lithofacies, stacking patterns, and lateral facies variations, and to interpret environmental dynamics during the deposition of carbonates from 'La Barre du Cengle ' in the Early Paleogene. Located in the SE of France, the elliptical Cengle Plateau stretches 7 km from east to west and is 2 km wide, featuring cliffs ranging in thickness from 20 to 35 m. These cliffs showcase grayish, beige, and pinkish limestones dominated by palustrine facies, forming part of the 'Calcaire de Saint Marc ' Formation of the Arc Basin. Sedimentary deposits within this interval were repeatedly subjected to subaerial exposure due to fluctuations in lake levels driven by climate, resulting in the organization of elementary sequences at decimetric to metric scales, which stack up into small-scale sequences at the decametric order. Deposition occurred under mainly subarid climatic conditions, with paleogeographic variations in the basin corresponding to changes in lake base levels over time and space. At least four frequencies of base level variation are present: very high and seasonal frequency, responsible for the formation of palustrine facies; high frequency, which generates the elementary sequences; medium frequency, which leads to the formation of the small-scale sequences; and low frequency which corresponds to the deposition of the entire set of limestones that form the Cengle cliff. The transition between lacustrine, palustrine, and pedogenic environments consistently occurs from west to east over time. In the more distal regions, the proportion of lacustrine facies tends to increase, and the thicknesses of the preserved sedimentary record tend to be greater. Conversely, palustrine and pedogenic facies predominate in the more proximal areas, typically resulting in decreased thickness. (c) 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Based on detailed sedimentological analyses of cores, interpretation of well logs and a set of geochemical measurements performed on lacustrine sediments, the palaeoenvironmental evolution and the sedimentary architecture of the Paleogene continental Vistrenque Basin (SE France) have been reconstructed. The analysis of sedimentary archives revealed three main stages of basin infill evolution: 1) a transgressive deep-lake basin (Priabonian-earliest Rupelian) whose sedimentation was dominated by terrigenous gravity-driven deposits during a period of high subsidence rate and fault activity and under a prevailing humid climate; 2) a forced-regressive, evaporative deep lake (early Rupelian) characterized by a drastic reduction in terrigenous supplies and deposition of evaporites in disconnected, compartmentalized sub-basins; 3) an overall long-term normal regressive stage (middle Rupelian to earliest Chattian) of lake infill characterized by an increase in terrigenous supplies and a vertical upward transition from deep-lake gravity-driven deposits to marginal lake and floodplain sedimentation. The onset of lake volume reduction and forced regression during the early Rupelian is recorded by 1) the reworking of marginal lake carbonates into the deep lake areas, 2) the deposition of organic-rich sediments (TOC>10%) coupled with sulphate-reduction processes in the deepest areas of the lake, 3) an important decrease in terrigenous supplies and 4) a long-term increase in δ18O of matrix-supported carbonates. This early Rupelian forced regression of the Vistrenque lacustrine system is interpreted to result from a terrestrial lowering in precipitation in response to global cooling during the Eocene-Oligocene Transition (EOT). The final infill of the Vistrenque lake system (late Rupelian-early Chattian) and the installation of a floodplain occurred in more humid conditions during a stage of decreased activity of the Nîmes Fault, prior to or during an early stage of the Liguro-Provençal rifting.

In the Tuamotu Archipelago, central South Pacific, some north-western atolls - e.g. Makatea, Mataiva, Tikehau, Rangiroa, Kaukura, Niau, and Anaa - exhibit raised reef limestones, locally at unusual elevations above present sea level. These islands were formerly interpreted to have been primarily uplifted by a lithospheric flexure generated by the load of nearby Society high volcanic edifices (Tahiti, Moorea). A reappraisal of previous field data and additional uranium-series, ESR and strontium isotope dating of the exposed reef limestones reveal the flexure-induced load model failed to account for the tectonic evolutionary history of the 7 uplifted north-west Tuamotu atolls, mentioned above. A new geodynamical scenario is proposed, implying the episodic thermal rejuvenation of the Society hotspot swell, thus generating an asthenospheric bump. At Makatea, Mataiva, Tikehau, Rangiroa and Kaukura, the basements and reef-rims were known to be Miocene in age. At Makatea, the closest island to the bump centre, the upper plateau peaks at present at 113 m above present mean sea level (pmsl), while on the other atolls, in peripheral positions, remnants of reef limestones are at 2.5 to 12 m above pmsl. At Niau, the atoll reef-rim, made up of a Pliocene core, locally overlapped by Late Pleistocene reef units, peaks at +7.5 m. At Anaa, the reef-rim is strictly composed of Late Pleistocene reef deposits at elevations of about +4-5 m. Makatea, Mataiva, Tikehau, Rangiroa and Kaukura, resting on the Pacific plate, have shifted northwestwards and as such entered the influence zone of the hotspot swell, approximately two million years (Ma) ago. The hotspot reheating phase that generated Moorea and Tahiti edifices, resulted in the uplift of Makatea - at estimated long-term rates of about 0.16 to 0.20 mm/yr - and of the nearer atolls. By contrast, the most southeastern ones (Niau and Anaa), at that time, located further south-east from the hotspot swell, are assumed to have continued subsiding according to expected standard crust cooling conditions. From approximately 0.5 Ma to 0.3 Ma, due to their continuous motion northwestwards, the most north-western islands ended up escaping the hotspot influence and started to re-subside. At the same time, Niau and Anaa Atolls, as subjected increasingly to the hotspot reheating effects, presumably in relation to the activity of sub-aerial Tahiti-Iti and Mehetia volcanoes, stopped subsiding and presumably were slightly uplifted prior to being stabilized. This is supported by the occurrence of Last Interglacial high-stand reefs at present-day elevations close to their presumed eustatic position. The uplift-stabilization-subsidence resumption scenario is consistent with a northwestward motion of islands carried away on a treadmill, i.e. the drifting Pacific plate, running over a rejuvenated mantle plume.

The combination of a detailed analysis of microfacies, diagenetic features and isotopic signatures (carbon and oxygen) of limestones from protohistoric statues and the comparison with substantial regional petrographic and geochemical databases have proven to be successful for constraining the provenance and providing insights into the production of statuary materials in Provence during the Iron Age. The limestones forming the sculptures from Roquepertuse (twin-headed "Hermes", the lintel with horses and the warrior seated cross-legged) and Rognac (warrior seated cross-legged) are interpreted to derive from lower Barremian carbonate formations from La Fare Massif, likely from near Coudoux, based on 1) micropalaeontologic markers (orbitolinids), 2) grain size, texture and grain composition (oolitic, oobioclastic and bioclastic grainstones), 3) dissolution features affecting ooid cortices and 4) carbon and oxygen isotope signatures. The bryozoan-echinoderm association and the occurrence of Amphistegina suggest that the bust of warrior from La Cloche oppidum (3rd to 1st century BCE) is made of a Miocene limestone from La Couronne Formation. Its isotope composition suggests a provenance from quarries located at Anse du Verdon or possibly further west. The fragment of scapulary tunic found in a disturbed archaeological context dated of 6th to 2nd century BCE on the Baou de Saint-Marcel oppidum, in Segobrige territories east of Massalia, is made of a vuggy limestone whose clotted peloidal-fenestral fabric and isotope signature are consistent with local, lower Pleistocene travertines. The young male head from the Ziem Museum was made of a planktonic foraminiferal, quartz-free limestone with Heterohelix for which no analogue is known in the region, thus suggesting that its place of manufacture is likely to be located outside Provence. Finally, the analyzed set of limestones from protohistoric sculptures, and of certain Provencal provenance, derive from stone production sites geographically close (<20 km) to the places of discovery. A set of non-invasive in situ techniques has been also used to discriminate among the possible sources (magnetic susceptibility, X-ray fluorescence chemical analysis, sound velocity, photogrammetry), but they appeared non discriminant for the present case.

New insights into the geodynamic evolution, the paleogeographic framework and the paleoclimatic setting of the Upper Eocene-Oligocene lacustrine basins from South-East France have been provided by an integrative approach combining geochronology, micropaleontology and stable isotope analyses. UPb dating on calcite, pollen-based climatostratigraphy and strontium and sulfur isotope signatures of sulfates provided a robust chronostratigraphic framework for the Upper Eocene and Oligocene succession from the Vistrenque, Alès and Roussillon basins. The thick Priabonian- lower Rupelian lacustrine succession from the Vistrenque Basin is interpreted to be deposited in a strike-slip basin associated with the latest stages of pyrenean shortening. Floral assemblages are used to reconstruct the vegetation cover in the lacustrine systems and their neighbouring lowlands and highlands. Composition of saltwater inferred from strontium and sulfur isotope signatures of sulfates, the occurrence of calcareous nannofossils, dinoflagellate cysts and pollen grains of mangrove-related plants provided strong evidence for marine intrusions into the Alès Basin during the Priabonian and the Vistrenque Basin during the Rupelian and Chattian. Paleogeographic reconstructions of Southeast France during the Priabonian and late Rupelian strongly suggest marine incursions from the Alpine Sea via two potential pathways: upper Rhône Valley via the Crest Sill and lower Rhône Valley via the Haut-Var Pyrenean synclines. On the other hand, Upper Oligocene evaporite basins in the Camargue area have been subjected to marine intrusions from the Western Mediterranean Sea following the collapse of the eastern pyrenean relief during the Liguro-Provençal rifting stage. Finally, pollen analysis and Climate Amplitude Method revealed a brief but significant stage of cooling and aridification at the very base of the Rupelian which could represent the regional and terrestrial expression of the global climate cooling following the Eocene-Oligocene Transition.

Normal fault zones can have a significant role on fluid flows as they can form barriers or drains (Agosta et al., 2010; Bense et al., 2013; Brogi and Novellino, 2015). In carbonates rocks, which are very sensitive to fluid-rock interactions, these fault-related fluid flows can strongly enhance or alter carbonate reservoir properties (Deville de Periere et al., 2017; Fournier and Borgomano, 2009). This work aims at determine fluid flow evolution in a carbonate reservoir affected by a normal fault. For this purpose, we studied structural and diagenetic properties of the Esperelles normal fault and the surrounding Barremian and Aptian formations located on the northern flank of Nerthe anticline (SE France). Esperelles fault developed during the Durancian uplift (Albian) and was weakly reactivated during the opening of Liguro-Provençal basin during Oligo-Miocene times. We defined seven different cements under cathodoluminescence (C0 to C6), their distributions along the outcrop, their geochemical properties (18O and 13C stable isotopes, Δ47 thermometry), and their ages (U-Pb). Diagenetic properties have been correlated with petrophysical measurements. We determined the paragenetic sequence, as well as the nature and temperature of the fluids that led to the formation of C1 and C6 cements. Four U-Pb ages have been obtained using an ELEMENT XR (Thermo-Fisher) SF-ICP-MS coupled to a 193 nm Excimer Laser (ESI) at CEREGE (Aix-en-Provence, France). These ages allowed to relate the C6 cementing phase with the opening of Liguro-Provençal basin. This study shows that fault zone development impacted reservoir fluid flows, leading to significant diagenetic events and development of heterogeneous reservoir properties. References Agosta, F., Alessandroni, M., Antonellini, M., Tondi, E. and Giorgioni, M.: From fractures to flow: A field-based quantitative analysis of an outcropping carbonate reservoir, Tectonophysics, 490(3–4), 197–213, doi:10.1016/j.tecto.2010.05.005, 2010. Bense, V. F., Gleeson, T., Loveless, S. E., Bour, O. and Scibek, J.: Fault zone hydrogeology, Earth-Science Rev., 127, 171–192, doi:10.1016/j.earscirev.2013.09.008, 2013. Brogi, A. and Novellino, R.: Low Angle Normal Fault (LANF)-zone architecture and permeability features in bedded carbonate from inner Northern Apennines (Rapolano Terme, Central Italy), Tectonophysics, 638(1), 126–146, doi:10.1016/j.tecto.2014.11.005, 2015. Deville de Periere, M., Durlet, C., Vennin, E., Caline, B., Boichard, R. and Meyer, A.: Influence of a major exposure surface on the development of microporous micritic limestones - Example of the Upper Mishrif Formation (Cenomanian) of the Middle East, Sediment. Geol., 353, 96–113, doi:10.1016/j.sedgeo.2017.03.005, 2017. Fournier, F. and Borgomano, J.: Critical porosity and elastic properties of microporous mixed carbonate-siliciclastic rocks, Geophysics, 74(2), E93–E109, doi:10.1190/1.3043727, 2009.

In recent years, pyroarchaeology has expanded rapidly and included experimental approaches. However, analyses of the combustion products carried by smoke (mainly soot and microcharcoal) and the study of fixing, recording, and preserving processes of this material on parietal surfaces remain limited. We therefore launched the ExTraS (Experiments on Traces of Soot) program, which aims to document the processes of fixation, recording, and preservation of combustion products in speleothems. We focused on various parameters, including the influence of wall surfaces, meteorological and seasonal conditions, and the nature of the fuel. Here, we present results acquired over several years (2015–2023) that combine macroscopic, microscopic, and colorimetric observations, as well as Raman microspectroscopy characterization. Our findings improve our understanding of the formation process of sooty speleothems observed at archaeological sites in rock shelters and caves.

In rock shelters and caves, the geo-archaeological reading of sediments can allow, in favourable cases, a micro-chronological study of traces of anthropogenic activities and in particular in the use of fire. If the recurrence in the use of fireplaces can sometimes be identified by a micromorphological study of these ground structures, it is very uncertain that all the different combustion episodes can be identified. It turns out that paleo-fire events can be recorded elsewhere than in the hearths. For instance, they can be recorded as soot marks trapped in speleothems, which are witnesses of fires made inside the caves. Thus they can be the object of a fuliginochronological study (lat. fuligo, fuliginosus: soot), which consists in studying the succession of soot deposits trapped in a matrix. Some limestone speleothems have another advantage, which is to be annually laminated. When it can be demonstrated, the joint study of soot films and calcite doublets allows the construction of precise paleo-fire chronicles. In this study, we demonstrate, with the help of both crystalline fabric analysis and seasonal variations of strontium (Sr) content, that the calcite doublets observed in the fine parietal carbonated crusts of the Grotte Mandrin archaeological site are indeed annual. We used LIBS technics (Laser Induced Breakdown Spectroscopy), which reveals relative variations of minor and traces elements, within speleothems carbonates, on an annual or sub-annual level. Soot film sequences can then be indexed to the annual carbonates precipitation calendar, giving precise paleo-fire chronicles. The study of the rhythmicities of human occupations at the Grotte Mandrin then becomes accessible with an unequalled precision.

Dans les abris-sous-roche et grottes, la lecture géoarchéologique des sédiments peut permettre, dans des cas favorables, une étude micro-chronologique des traces d’activités anthropiques et en particulier de l’usage du feu. Si la récurrence dans l’utilisation des foyers peut parfois être identifiée par une étude micromorphologique de ces structures au sol, il n’est pas évident que l’ensemble des différents épisodes de combustion puisse y être identifié. Il se trouve que les événements de paléo-feux peuvent être enregistrés ailleurs que dans les foyers, par exemple sous la forme d’imprégnations de suie enregistrées dans les spéléothèmes, témoins des feux passés dans les cavités ; elles peuvent faire l’objet d’une étude fuliginochronologique (lat. fuligo , fuliginosus : suie), qui consiste à étudier la succession des dépôts de suie piégés dans une matrice. Certaines concrétions calcaires ont un autre avantage, celui de présenter des lamines pouvant être annuelles. Lorsque cela peut être démontré, l’étude conjointe des films de suie et des doublets de calcite permet de caler les chroniques de paléo-feux sur une échelle micro-chronologique de temps mesuré. Dans cette étude, nous démontrons, grâce à l’analyse conjointe des alternances de fabrique cristalline et des variations saisonnières de la teneur en strontium (Sr), que les doublets de calcite observés dans les fins encroûtements carbonatés pariétaux du site archéologique de la Grotte Mandrin sont annuels. Pour ce faire, nous avons recours à la spectroscopie sur plasma induit par laser (LIBS – Laser Induced Breakdown Spectroscopy ) qui permet de révéler des variations relatives d’éléments mineurs et traces dans ces concrétions avec une échelle annuelle à sub-annuelle. Les séquences de films de suie peuvent donc être indexées sur le calendrier annuel de la précipitation des carbonates et les chroniques de paléo-feux calées sur une échelle chronologique relative et précise à l’année près, voire la saison. L’étude des rythmicités des occupations humaines sur le site de la Grotte Mandrin devient alors accessible avec une résolution jusqu’alors inégalée.

Integrated sedimentological, diagenetic and structural analyses have been carried out on microporous and tight Urgonian (Barremian – Aptian) limestones in a study area in SE France in order to understand the influence of diagenetic changes and structural deformation on the spatial distribution of reservoir properties. A diagenetic history for the carbonates was established and was divided into phases which correspond to episodes of regional geodynamic activity. Petrographic (optical, SEM and cathodoluminescence microscopy), structural and geochemical (δ18O, δ13C) studies were carried out to characterize the cement phases in the carbonates, especially micrite and blocky calcite, and to investigate their relationship with episodes of fracturing.Eleven calcite cement phases and four micritic cement phases were identified in relation to the two main phases of structural deformation which affected the Urgonian limestones. A first phase of micrite cementation occurred early in the diagenetic history and was linked to early marine cementation at the tops and bases of depositional cycles during the Barremian. A major phase of micrite recrystallization, which generated microporosity in carbonates that had previously been preserved from early cementation, was followed by a first phase of blocky calcite which occluded intergranular pore spaces. The blocky cement formed in a shallow burial meteoric environment and contributed to the preservation of microporosity during late Durancian tectonism (Albian – Cenomanian). A second phase of blocky calcite is associated with fracture activation during latest Eocene (Priabonian) – Oligo‐Miocene extension.Reservoir rock‐types (RRTs) proposed in a previous study were consistent with the diagenetic characteristics and the results of δ13C / δ18O analyses. Microporous RRTs formed as a result of early to late shallow burial processes and display low δ13C values; whereas cemented RRTs developed both due to early marine cementation (with high δ13C values) and/or as a result of cementation related to fluid flow linked to the reactivation of faults and fractures. This suggests that some late diagenetic and microstructural processes were pre‐determined by early diagenetic changes in the carbonates. The resulting stratigraphic architecture consists of a vertical stacking of weakly fractured microporous limestone intervals alternating with highly fractured, cemented limestone units.

Upper Barremian - Lower Aptian inner platform "Urgonian" limestones in the Mont de Vaucluse region, SE France, consist of alternating metre-scale microporous and tight intervals. This paper focuses on the influence of structural deformation on the reservoir properties of the Urgonian limestone succession in a study area near the town of Rustrel. Petrographic, petrophysical and structural data were recovered from five fully-cored boreholes, from the walls of a 100 m long underground tunnel, and from a 50 m long transect at a nearby outcrop. The data allowed reservoir property variations in the Urgonian limestones to be studied from core to reservoir scale. Eleven Reservoir Rock Types (RRTs) were identified based on petrographic features (texture, grain size), reservoir properties (porosity, permeability), and the frequency of structural discontinuities such as fractures, faults and stylolites. Tight and microporous reservoir rock types were distinguished. Tight reservoir rock types were characterised by early cementation of intergranular pore spaces and by the presence of frequent structural discontinuities. By contrast microporous reservoir rock types contained preserved intragranular microporosity and matrix permeability, but had very few structural discontinuities. Observed vertical alternations of microporous and tight rock types are interpreted to have been controlled by the early diagenesis of the Urgonian carbonates. Deformation associated with regional-scale tectonic phases, including Albian - Cenomanian "Durancian" uplift (similar to 105 to 96 Ma) and Pyrenean compression (similar to 55 to 25 Ma), resulted in the modification of the initial petrophysical properties of the Urgonian limestones. An early diagenetic imprint conditioned both the intensity of structural deformations and the associated circulations of diagenetic and meteoric fluids. Evolution of the Reservoir Rock Types is therefore linked both to the depositional conditions and to subsequent phases of structural deformation.

Summary Fractures in folded carbonate layers are sampled along a scan-line, such as an “Along Well Measure Depth”. We deciphered 11 types of brittle structures (stylolites, joints, tension-gashes, faults) which are relatively date as pre-, syn- and post folding. Brittle stages are plot on the loading path and at each step we characterize the reservoir properties and Nelson reservoir type. With burial, the reservoir would evolve from type I to type II. Then, the tectonic inversion trigger fractures and faults which increased and decreased the fracture and matrix contribution respectively The data-base is shown like a well data-set what allows challenging and calibrate the structural analysis performable from a well.

Bed-perpendicular, opening-mode diffuse fractures are common features in carbonate rocks because they become brittle during the first stages of diagenesis. Early-fractures could be independent of tectonics and form a background structural network from sub-millimeter to 10's of centimetres scale. This study focuses on the outcrop-to-micro scales structural, stratigraphic, and petrographic characterization of Lower Cretaceous, shallow-water, tight limestones of the Inner Apulian Platform exposed along the axial sector of the southern Apennines fold-and-thrust belt, Italy. This work aims at understanding the formation of early diagenetic fractures during the first stages of sediment lithification, and on their impact on subsequent deformation mechanisms associated to polyphase tectonics. The results of field structural surveys, of petrographic and cathodoluminescence analyses of representative samples unravel the main structural-diagenetic processes in shallow-water carbonates. We document that early brittle fractures were intrinsically related to the host rock pore type and cementation processes, and summarize the overall time-dependant evolution of the structural assemblages in a conceptual model. This model includes all abutting and crosscutting relationships among the various structural elements from field to thin-section observation, and form the now days fracture network.

Fractures in rocks are sensitive cursers that may enhance porosity and permeability. This is particularly true in carbonates because background fractures might be ubiquitous after embrittlement at early burial (Lavenu & Lamarche, 2018). Barren fractures at depth are susceptible to chemical reactions with underground fluids and cementation that might totally or partially reduce porosity and permeability (Laubach et al., 2019; Aubert et al., 2019). Hence, early background fractures with long lasting tectonic history and structural diagenesis, in addition to fractures neo-formed at any time during burial, tectonic inversion and folding join the game of matrix/fracture permeability and porosity modification. To predict the fractures contribution to flow in Naturally Fractured Reservoirs, it is fundamental to know the fracture sequence and geometry resulting from the geological history in folded carbonates, from the host-rock embrittlement to the present-day situation. At any step, we intent quantifying the fracture geometry and estimating their contribution to the host reservoir properties. The study is performed in Upper Jurassic to Lower Cretaceous carbonates (Oxfordian, Tithonian, Berriasian) formed in the South-Provençal Basin. From deposition to present-day, the platform carbonates underwent alternating subsidence, uplift, erosion and folding. We sampled a scan-line along a horizontal path across both flanks of the Mirabeau Anticline (SE France). We measured all tectonic and stratigraphic features crossed by the line, checked their nature and position. We deciphered their chronological relationships with respect to each other and to the bed tilting. We compiled all cross-cutting relationships into a coherent sequence of deformation of pre-, syn- and post-fold structures and correlated it to burial, uplift and folding of the host rock. At each brittle stage, the fracture pattern was characterized in terms of architecture, mechanical stratigraphy and reservoir properties in order to draw a time-path in a matrix versus fracture permeability and porosity table (Nelson Reservoir types) during 150My. After embrittlement, the host-rocks bear fractures, pressure-solution, faulting, folding and erosion. If it was a reservoir, its Nelson type would have evolved from IV to III during the burial and initial brittle deformation. The tectonic inversion and onset of multiple-scale brittle structures would have increased and decreased the fracture and matrix contribution respectively and the reservoir evolved to types II and I. During the 150My history, fracture porosity and permeability depends on their geometry (veins versus tension gashes) and cementation. This results in several switches from type II to I as a function of the fracture timing, geometry, connectivity and diagenesis. Aubert I. et al. (2019). Imbricated structure and hydraulic path induced by strike-slip reactivation of a normal fault in carbonates. Fifth International Conference on Fault and Top Seals, 8-12 September 2019, Palermo, Italy. Bestani L.et al. (2016) Reconstruction of the Provence Chain evolution, southeastern France., Tectonics Vol: 35, p.1506–1525 Laubach, S. E. et al. (2019) The role of chemistry in fracture pattern development and opportunities to advance interpretations of geological materials. Reviews Geophysics, 57. Lavenu A.P.C., Lamarche J. (2018) What controls diffuse fractures in platform carbonates? Insights from Provence (France) and Apulia (Italy), JSG 108, p. 94-107

SummaryBed-perpendicular diffuse fractures are common features in carbonates that could be affected by early embrittlement process, which may enhance vertically persistent, opening-mode fractures during the first stages of diagenesis. Early-developed fractures could be independent of tectonics and form a background structural network at different scale. This study focuses on the structural, stratigraphic and petrographic characterization, from outcrop- to micro-scale of Lower Cretaceous, shallow-water, tight limestones pertaining to the Inner Apulian Platform paleogeographic/tectonic domain. These carbonates consist of a wide spectrum of inner platform-platform margin calcareous facies, namely mudstones, wackestones, packstones, grainstones, bindstones, floatstones and rudstones. The presented work is addressed on understanding the development of the early diagenetic features which occurred during the first stages of the sediment lithification processes and the description of the formation, geometry and distribution of the contemporaneous and subsequent structural elements. Field analyses in concert with laboratory analyses unrevealed the main structural-diagenetic events which affected the studied shallow-water carbonates. Petrographic analyses highlight early fractures are intrinsically related to the host rock pore type. Finally, evolution of the fracture network is summarized in a conceptual model by taking into account the several tectonic phases which affect the Monte Alpi sector

Fracture properties are important in carbonate reservoir characterization, as they are responsible for a large part of the fluid transfer properties at all scales. It is especially true in tight rocks where the matrix transfer properties only slightly contribute to the fluid flow. Open fractures are known to strongly affect seismic velocities, amplitudes and anisotropy. Here, we explore the impact of fracture evolution on the geophysical signature and directional V-p anisotropy of fractured carbonates through diagenesis.For that purpose, we studied a meter-scale, parallelepiped quarry block of limestone using a detailed structural and diagenetic characterization, and numerous V-p measurements. The block is affected by two en-echelon fracture clusters, both being formed in opening mode (mode 1) and cemented, but only one being reactivated in shear. We compared the diagenetic evolution of the fractures, which are almost all 100% filled with successive calcite cements, with the P-wave velocities measured across this meter-scale block of carbonate, which recorded the tectonic and diagenetic changes of a South Provence sedimentary basin.We found that a directional V-p anisotropy magnitude as high as 8-16% correlates with the reactivated fractures' cluster dip angle, which is explained by the complex filling sequence and softer material present inside the fractures that have been reactivated during the basin's tectonic inversion. We show that although a late karstification phase preferentially affected these reactivated fractures, it only amplified the pre-existing anisotropy due to tectonic shear. We conclude that V-p anisotropy measurements may help to identify the fracture sealing/opening processes associated with polyphased tectonic history, the anisotropy being independent of the current stress state. This case shows that velocity anisotropies induced by fractures resulted here from a cause that is different from how these features have often been interpreted: selective reactivation of sealed fractures clusters rather than direction of currently open ones. (C) 2017 Elsevier B.V. All rights reserved.

Summary: Physical properties of carbonate rocks cannot be fully captured from laboratory-sized samples. Indeed, heterogeneous facies distribution and/or diagenetic alterations may lead to significant variations in petrophysical properties within few meters. In carbonates, diagenetic transformations are tightly related to nature of fluids flowing through the formations, e.g. via fractures network. Consequently, reservoir properties may have patchy distribution, and may not be correlatable (e.g. using facies distribution or wells-logs correlations) within few meters. Our works aim at characterizing carbonates anisotropy at different scales, and are subject of two presentations at SEG's 87th Annual Meeting. This abstract deals with the second part of our approach, that's to say characterizing impact of diagenetic alteration on reservoir properties and seismic anisotropy, from centimeter to multi-meter scale. This part of the works integrate data from centimeter-scale (mini-cores), decimeter-scale (5″ cores), multi-meter (ultrasonic crosshole), and hectometer-scale (seismic), which have been measured at suitable frequency ranges (1MHz, 250kHz, 50kHz, and 1–100Hz, respectively). Although anisotropy is measureable at every scales, its origins vary according to scale. In this study, it is shown that matrix of porous samples are weakly anisotropic as a result of inter-crystalline pores. At centimeter-scale, anisotropy can also be related to: (1) patchy distribution of some physical properties, (2) local cracks distribution, and (3) thick single fractures. The lack of correlation between stiffness components from seismic-scale measurements, and laboratory to multi-meter scale ones emphasizes the fact that, when fracturing dominates, measured anisotropy is dominated by fracture/fault related anisotropy and matrix-related anisotropy may be lost. So that, scale effect must be handled carefully in anisotropy analyses, especially for carbonate formations. This paper has been withdrawn from the Technical Program and will not be presented at the 87th SEG Annual Meeting.

In the southwestern part of Algeria, the Cenomanian-Turonian marine deposits build up a prominent ledge in a perched syncline (Ksour Mountains, western Saharan Atlas) or at high radius of curvature (Guir Basin). The petrographical analysis of the Cenomanian-Turonian deposits of the Ksour Mountains and of the Guir Basin reveals unexpected assemblages of roveacrinoidal ossicles comparable with those formerly reported from the Tinrhert area. For the first time, isolated ossicles of genuine and undisputable Roveacrinidae are illustrated. Three sections, Djebel Rhoundjaia (western Saharan Atlas), Berridel and Kenadsa (Guir Basin), were scrutinized to recognize the microcrinoidal sections within the carbonate microfacies and to compile the successive occurrence of respective roveacrinid taxa (besides the classical search for standard index microfossils) in an attempt to pinpoint more precisely the position of the Cenomanian-Turonian boundary (C/T B). These assemblages are particularly morphologically and taxonomically diverse with three species of genus Roveacrinus and one of genus Orthogonocrinus. The presence of Saccocomidae (Applinocrinus) is especially unusual in such stratigraphic levels. The relative abundance and diversity of Roveacrinidae evidence a peak when approaching the C/T B. Such an event is recurring in the latest Cenomanian in various Tethyan and Atlantic areas. These fluctuations are consistent with a high surface-water productivity just before the C/T B. (C) 2017 Elsevier Masson SAS. All rights reserved.