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Carnets Geol., vol. 25, no. 07 David J. Jutson, Michael D. Bidgood & Ben Johnson.- Microfossil and nannofossil analysis of the Upper Cretaceous to Lower Paleogene interval from two wells in the locality of the U.K. North Sea 'Silverpit Crater'.- Micropaleontological and nannopaleontological analyses have been carried out on ditch cuttings samples from two wells (Arco British 43/24-3 and British Gas 43/25-1), which penetrated the 'Silverpit Crater' structure in the Southern North Sea Basin (UK Sector). A stratigraphic gap (within the limits of resolution imposed by sampling constraints) has been identified between chalky limestones of Maastrichtian age, which are overlain by sediments of latest Paleocene age or younger. Accepting an impact-origin for the structure, the gap represents an impact-event, which occurred almost certainly post Cretaceous and Early Paleocene times and thus probably within the Late Paleocene, close to the Paleocene-Eocene boundary, ruling out an association with the K/P extinction impact. In well 43/25-1 a short interval of mixed microfaunas and nannofloras was observed, which is suggested as being related to 'resurgence deposits' entering the crater immediately after the impact-event. Geologia Acta, vol. 23, no. 9, 18 p. DomĂnguez-Carretero D., Villanova-de-Benavent C., TorrĂł L., Pujol-SolĂ N., Bover-Arnal T., Mestre Ă., Aiglsperger T., RamĂrez A., RodrĂguez J., Espaillat J. & Proenza J.A. (2025).- Mineralogy, geochemistry and origin of karst bauxite deposits from the Reserva Fiscal Ăvila, SW Dominican Republic.- The energy transition, which aims to reduce carbon emissions and to slow down climate change, demands an ever-increasing supply of the so-called "critical metals". Rare-earth Elements and Yttrium (REY) are among the most critical metals, as they are indispensable in most technologies associated with the generation and storage of renewable energy. In recent years there has been a growing interest in the potential of karst bauxites as non-conventional sources of REY and other critical metals such as Sc and Ga. The Sierra de Bahoruco (SW Dominican Republic) contains the most REY-enriched karst bauxites globally. In view of the high potential for hosting important REY contents, the Dominican Republic government has declared the Reserva Fiscal Ăvila (RFA), a state-owned area within the Sierra de Bahoruco for assessment and exploration of its REY resources. In this study, we present the first data on the mineralogy and composition of bauxitic rocks from the RFA. The bauxitic deposits comprise clayey bauxites and Fe-rich bauxites that are composed predominantly of Al-oxyhydroxides (gibbsite, boehmite and nordstrandite), kaolinite and Fe-oxyhydroxides. The bauxites are enriched in REY, with a median value of 1,310ppm and up to 2,542ppm, with a consistent enrichment in Light REE (LREE) and Y compared to Middle REE (MREE) and Heavy REE (HREE). The positive correlation between the contents of REY and Th, and negative correlation with K, makes gamma-ray spectrometry an appropriate tool for the exploration. In addition, bauxitic rocks from the RFA contain significant Sc (up to 105ppm) and Ga (up to 54ppm) contents, and their extraction could potentially represent a substantial economic surplus to the revenue generated solely from the aluminum production. BoletĂn de la Sociedad GeolĂłgica Mexicana, vol. 77, no. 01, A031024 AndrĂ©s Michael Vite Galindo, Ana MarĂa Soler Arechalde & VerĂłnica Ortega Cabrera.- Aportaciones a la cronologĂa de la plaza de la PirĂĄmide de la Luna, TeotihuacĂĄn, MĂ©xico - Contributions to the chronology of the Moon Pyramid square, TeotihuacĂĄn, Mexico.- The chronology of the Pyramid of the Moon square in TeotihuacĂĄn was determined through relative dating of the ceramic remains present in the different strata sampled, during archaeological excavations carried out since the 1960s, so establishing dating through archaeomagnetism will allow having a database that complements those obtained in different urban sectors such as La Ciudadela, Xalla and Teopancazco, thus generating greater certainty in the chronology and understanding of the phenomena of urban growth and renewal of the ancient city. In this work, the results of the first archaeomagnetic dating carried out in the Plaza de la Luna are presented, based on the sampling of three floors of gravel and a tamped floor, corresponding to the different construction moments of this space, with the aim of establishing a sequence chronological base, with which to compare future dating, both for the square and for other public spaces in the city. Mineralogia, vol. 56, no. 1, p. 34-43 Walczak K.A., Wlodek A., Cuthbert S., Carter I.S.M. & Ziemniak G.- Long story encrypted in a small grain â zircon from meta-andesite in the Lower Köli Nappes reveals a complex history of the Virisen Arc Terrane, Scandinavian Caledonides, Sweden.- This short report presents the investigation results on the zircon from meta-andesitic rock from the Ankarede Volcanite Formation of the Lower Köli Nappe Complex in Scandinavian Caledonides. Previous U-Pb dating revealed a wide span of dates ranging from ca. 520 to ca. 480 Ma, with a mean age of 491 ± 3 Ma for the zircon cores. Using cathodoluminescence and back-scattered electron imaging, along with chemical mapping, we identified distinct zones within the zircon grains; 1) cores of clear magmatic provenance, 2) mantles also of magmatic origin but with a slightly different chemical composition and 3) zircon rims that suffered metamictisation and fluid-induced alterations. These findings highlight a complex growth history and alteration of studied zircon that affect the interpretation of zircon dating results. This research underscores the importance of detailed zircon studies for understanding the intricate processes involved in the magmatic and metamorphic evolution of Virisen terrain in Scandinavian Caledonides. Mineralogia, vol. 56, no. 1, p. 34-43 Walczak K.A., Wlodek A., Cuthbert S., Carter I.S.M.. & Ziemniak G. (2025).- Long story encrypted in a small grain â zircon from meta-andesite in the Lower Köli Nappes reveals a complex history of the Virisen Arc Terrane, Scandinavian Caledonides, Sweden.- Long story encrypted in a small grain â zircon from meta-andesite in the Lower Köli Nappes reveals a complex history of the Virisen Arc Terrane, Scandinavian Caledonides, Sweden. This short report presents the investigation results on the zircon from meta-andesitic rock from the Ankarede Volcanite Formation of the Lower Köli Nappe Complex in Scandinavian Caledonides. Previous U-Pb dating revealed a wide span of dates ranging from ca. 520 to ca. 480 Ma, with a mean age of 491 ± 3 Ma for the zircon cores. Using cathodoluminescence and back-scattered electron imaging, along with chemical mapping, we identified distinct zones within the zircon grains; 1) cores of clear magmatic provenance, 2) mantles also of magmatic origin but with a slightly different chemical composition and 3) zircon rims that suffered metamictisation and fluid-induced alterations. These findings highlight a complex growth history and alteration of studied zircon that affect the interpretation of zircon dating results. This research underscores the importance of detailed zircon studies for understanding the intricate processes involved in the magmatic and metamorphic evolution of Virisen terrain in Scandinavian Caledonides. Geologia Acta, vol. 23, no. 8, 13 p. RoquĂ©-Rosell J., Ibåñez-Insa J., Granado P., MartĂn-MartĂn J.D., Ălvarez-Pousa S., CerdĂ -DomĂšnech M. & JimĂ©nez-Franco A. (2025).- Major-element analysis of the La Alquimia CompañĂa AnĂłnimarock collection: Establishing a geochemical repository for the systematic classification of Iberian karstic bauxite and kaolin deposits.- The La Alquimia CompañĂa AnĂłnimarock collection comprises a diverse range of rock samples collected across the Iberian Peninsula to identify bauxites suitable for aluminum oxide production. In this study, the major-element compositions of the rock samples were analysed using non-destructive portable X-Ray Fluorescence (XRF). The data were processed through Principal Component Analysis (PCA), calibrated and used to calculate the Index of Laterisation/Index of Bauxitisation (IOL/IOB) and the Chemical Index of Alteration (CIA). The PCA results revealed SiO#8322;, Al#8322;O#8323; and Fe#8322;#8322;O#8323; as the key components explaining most of the rock samples compositional variance. The calibrated data provided the major-element compositions, confirming that the rock samples predominantly correspond to karstic bauxites and kaolin deposits. For the karstic bauxite samples, the calculated IOL/IOB values, combined with theSiO#8322;--AlâOâ--FeâOâ ternary diagram, facilitated their classification. The samples were categorised into bauxitic types associated with regions of moderate uplift and karst development and near-lateritic types indicative of advanced weathering processes typical of more stable continental terrains under warm and humid climates. Besides, the calculated CIA values and the Al#8322;O#8323;-CaO*+Na#8322;O-K#8322;O ternary diagram were applied to classify the kaolin deposits. This approach also identified compositional variations among the kaolin rock samples, reflecting differences in their formation. The rock collection serves as a repository for advancing the regional understanding of the formation, distribution and geochemical trends of Iberian karstic bauxite and kaolin deposits. Moreover, these deposits hold significance as potential sources of Al, Li and REE, emphasising the value of the La AlquĂmia CompañĂa AnĂłnima collection as a geochemical repository, particularly considering the growing demand for these critical resources. Carnets Geol., vol. 25, no. 06 Olev Vinn, Andrej Ernst, Mark A. Wilson & Ursula Toom.- Symbiosis between bryozoans with erect cribrate colonies and rugose corals from the lower Katian (Upper Ordovician) of Estonia.- Specimens of the rugose coral Streptelasma? sp. are found intergrown with a host bryozoan Oanduellina bella in the lower Katian of Estonia. Rugosa also occur in the bryozoan Proavella proava. This is the earliest and only known record of endobiotic rugose symbionts in cryptostome bryozoans from the Late Ordovician of Baltica. The erect bryozoan colonies provided symbiotic Rugosa with both a higher and more advantageous tier for feeding in the water column and a hard substrate that these encrusting Rugosa required. The rugose corals may have protected the bryozoans with their stinging cells against predators. The lack of malformations in the bryozoan zooid architecture and their normal dimensions around the Rugosa show that the relationship between the Rugosa and bryozoans could have been mutualistic, which is similar to many other Rugosa-bryozoan associations in the Late Ordovician of Baltica, although the exact nature of this association remains uncertain. Geologia Acta, vol. 23, no. 7, 17 p. MartĂn-Closas C., Lozano-FernĂĄndez I., PĂ©rez-Cano J. & Bover-Arnal T. (2025).- The non-marine Lower Cretaceous of El Montsec thrust sheet (South-Central Pyrenees).- The aim of this study is resolving uncertainties on the lithostratigraphy and chronostratigraphy of the non-marine Lower Cretaceous of El Montsec thrust sheet, which contains the most developed record of such facies in the central Pyrenees (Catalonia, Spain). The materials, traditionally known as "El Montsec Charophyte Limestones", overlie upper Berriasian marine limestones and belong in fact to two different stratigraphic units, separated by an angular unconformity, which is represented by an irregular karstic surface. The lower unit, newly defined as the Cova dels Lladres Intraclastic Limestone Formation, is composed by metric-scale fining-upward parasequences with black intraclast conglomerates at the base covered by charophyte limestones at the top. This first non-marine unit is attributed to the lower Barremian Eurasian charophyte biozone Atopochara trivolvis triquetra. The upper non-marine unit, (revisited El Montsec Charophyte Limestone), is made of metric-scale fining-upward parasequences of charophyte limestones. Ferruginous marls at the base of the upper unit have yielded charophytes of the Hemiclavator neimongolensis neimongolensis Eurasian charophyte biozone, corresponding to the early-late Barremian boundary. El Montsec Charophyte Limestone Formation transitions laterally to La Pedrera de RĂșbies Lithographic Limestones Formation, which includes the two famous fossil Konservat LagerstĂ€tten of La Pedrera de MeiĂ and La Cabroa. In sum, the non-marine Lower Cretaceous succession of El Montsec thrust sheet shows at its base a stratigraphic gap ranging from the upper Berriasian to the early Barremian. Furthermore, the angular unconformity separating the Cova dels Lladres Formation and El Montsec Formation clearly reflects the strong tectonic activity associated with the Barremian Iberian rift, which has been linked with the opening of the Bay of Biscay. Mineralogia, vol. 56, no. 1, p. 23-33 Bal S., Nejbert K., Michalski K., Domanska-Siuda J., Manby G., Holda-Michalska A. & SlĂĄma J. (2025).- Petrographic and mineralogical characteristics of diagenetic overprinting in Neoproterozoic diamictites from Murchisonfjorden, Nordaustlandet, Svalbard.- Petrographic and mineralogical characteristics of diagenetic overprinting in Neoproterozoic diamictites from Murchisonfjorden, Nordaustlandet, Svalbard. The diagenetic processes exhibited by the Neoproterozoic diamictites from Murchisonfjorden (Nordaustlandet, NE Svalbard) are presented. Diamictite samples from the Cryogene Polarisbreen Group - the Petrovbreen Member of the Elbobreen Formation and the Wilsonbreen Formation were analysed. The mineralogical associations composed of chlorite group minerals (chamosite), albite, calcite, Fe-dolomite, clay minerals (illite) and quartz, recognized by integrated optical microscopy, scanning electron microscopy (SEM) and Raman spectroscopy techniques are typical for an advanced stage of mesogenetic diagenesis. Low-grade burial mineral associations were not identified. Our investigations indicate that during diagenesis increased heat flux accompanied fluid migration and remineralization. Identified Fe-Ti â oxides, anatase in thin sections and magnetite identified by rock-magnetic experiments are the products of the secondary diagenetic mineralization. The ferromagnetic carriers representing primary depositional remanence magnetization (DRM) were not preserved. Geologia Acta, vol. 23, no. 6, 23 p. Alçiçek H., Bouchal J.M. & Alçiçek M.C. (2025).- Sedimentology and isotope geochemistry of Early Pliocene shallow lacustrine dolomitic succession in the Baklan Basin, Southwestern TĂŒrkiye.- A multiproxy study of the Lower Pliocene (Zanclean) shallow lacustrine succession in the southwestern margin of the Baklan Basin (southwestern Anatolia, TĂŒrkiye) provides new insights into the paleoclimatic and paleohydrologic evolution of an extensional basin located at the top of the western Taurides mountain range in the southeastern Mediterranean region. Detailed petrographic, sedimentological, palynological and stable isotope analyses on Mg-rich carbonates were carried out on the dolomitic succession in the Sapaca locality in the basin, indicating a vegetated, quiet to slow-moving, low-gradient, perennial, alkaline shallow lake environment under warm and arid climate conditions. The stable isotopic analysis of the dolomitic carbonates exhibits a narrow range of values (-1.31<ÎŽ18O<+5.82â° and -7.10<ÎŽ13C<-2.10â°) and the ÎŽ18O-ÎŽ13C correlation (r=0.70) indicates a hydrologically closed lake. Two types of dolomite are identified in the studied section. Type-1 crystals formed mainly as a result of primary precipitation of dolomite in the shallow lake, whereas type-2 crystals probably indicate microbially controlled dolomite precipitation. The palynological record from Sapaca reveals that the Early Pliocene paleoenvironment was dominated by steppe and open vegetation with some isolated shrubs. Similar paleoclimatic and paleovegetational conditions are observed in other Anatolian basins and in the southern Mediterranean region. Therefore, the results of this study demonstrate that the shallow lacustrine system of the Baklan Basin serves as a good analogue for understanding Early Pliocene warmth and aridity in this region. Geologia Acta, vol. 23, no. 5, 12 p. Benaiges-FernĂĄndez R., Palau J., Urmeneta J., Cama J., Soler J.M. & Dold B. (2025).- Comparative study of iron and trace element mobilization during Fe-oxide bioreduction in mine tailings: a case study of Ensenada Chapaco (Chile) and Portman Bay (Spain).- Bioreduction of Fe-oxides in mine tailings deposited under marine conditions releases Fe and associated trace elements (e.g. Ti, Ni, Cd, Pb), leading to contamination of the marine environment. Sea-Tailings Disposal (STD) along the northern coast of Chile (Ensenada Chapaco) and along the eastern coast of Spain (Portman Bay) results in an adverse impact on the environment. This paper focuses on bioreduction under marine conditions. To this end, two column experiments were carried out with samples from Portman Bay and Ensenada Chapaco. Lactate (i.e.organic matter source) was supplied during the experiments. The results obtained are compared with those from batch experiments performed under similar conditions.In the column filled with Portman Bay tailings, the high content of magnetite (15wt%) in contact with water gives rise to a large magnetite surface area and abundant Fe(III), which results in a high release of Fe(II) and Trace Elements (TE). Since Fe(II) adsorbs onto the magnetite surface reducing the availability of Fe(III), the magnetite bioreduction and the consequent TE release decrease after 2000h. By contrast, the magnetite bioreduction lasts longer (3000h) in the column with Ensenada Chapaco tailings. This is because a lower magnetite content in the tailings (1wt%) provides a smaller reactive surface area yielding less Fe(III). Consequently, the concentrations of Fe(II) and TE in the output solutions are lower, which slows down the Fe(II) adsorption onto magnetite. This results in a longer magnetite bioreduction. Bioreduction is regulated by the availability of Fe(III) in both columns. It is inferred that the bioreduction rate diminishes as a function of time and increases as a function of soluble Fe(II) concentration. Moreover, the concentrations of TE released from the two bioreduced tailings exceed the elemental concentrations under marine conditions. Mineralogia, vol. 56, no. 1, p. 13-22 Walters J.B.. & Gies N.B. (2025).- Syn-volcanic melt-rock reactions recorded in peridotitic xenoliths from Scania, S Sweden.- MinPlotX: A powerful tool for formula recalculation, visualization, and comparison of large mineral compositional datasets. MinPlotX is an open-source software for mineral formula recalculation and compositional plotting providing an easy-to-use stand-alone graphical user interface (GUI) as well as an advanced programming interface (API). The aim of MinPlotX is to provide publication-ready tables of mineral formulae and plots of mineral composition. The new GUI-based approach allows for a wider variety of calculation and plotting options, including both commonly used pre-defined mineral specific diagrams and a large variety of multi-dimensional diagrams that can be created quickly and easily by the user. The most powerful feature is the addition of nearly any kind of numerical or categorized metadata, such as sample name, analysis location, trace element concentration, age, and others, that can be used to subdivide or contour data. The modular nature of the program makes it possible to add new mineral formula recalculation and plotting routines, as well as other data science tools, without changing the overall structure of the program. Therefore, MinPlotX provides advanced users the means to add new routines and interact with the program through the API, while simultaneously providing a simple and effective platform for users who have no programming experience or do not have access to MATLABÂź. Geologia Acta, vol. 23, no. 3, 21 p. Urrutia-Fucugauchi J., PĂ©rez-Cruz L., Venegas-Ferrer R. & SĂĄnchez-Solis P. (2025).- The Chicxulub crater drilling program - continuous coring, well logging and core analyses reviewed.- Continuous core recovery, core scanning and logging are used for borehole characterization and petrophysical analyses in the Chicxulub drilling projects. The crater formed by an asteroid impact on the Yucatan platform ~66Ma ago, marking the Cretaceous/Paleogene (K/Pg) boundary. The K/Pg boundary clay layer, characterized by the Ir and platinum group element anomaly, has been studied worldwide. The crater has a ~200km rim diameter and is covered by up to ~1km of carbonate sediments, with studies based on geophysical surveys, drilling and ejecta deposits. The Yaxcopoil-1 borehole, drilled in the southern crater terrace zone sampled the post-impact carbonates, impact breccias and target Cretaceous carbonates. The M0077A borehole drilled in the marine sector sampled the peak ring succession, with the post-impact carbonates, impact breccias, melt and basement. The Yaxcopoil-1 and M0077A boreholes were continuously cored from about 400m to 1511 and 1335m, respectively and sampled distinct crater structures. Studies provide constraints on the crater formation, crustal deformation, lateral/vertical displacement, ejecta emplacement and crater collapse. Impact breccias are heterogeneous materials, with clasts of melt, carbonates and basement in carbonate-rich and melt-rich matrix. The lower breccias were emplaced by high-temperature basal surges, followed by collapse of the impact plume and lateral curtains. The upper breccias are reworked deposits of the post-collapse stage. The crater formed a depositional basin, filled with sediments that preserve records of sea level and sediment transport across the platform. Core analyses and scans provide constraints on the structure, stratigraphy, textures, mineralogy, deformation and hydrothermal alteration. Studies show the usefulness of continuous coring and core analyses to constrain the crater formation, impact deformation, ejecta and impact dynamics. Geologia Acta, vol. 23, no. 4, 22 p. Shahab M., Ali L. & Alshehri F. (2025).- Integrated remote sensing, petrographic and mineralogical techniques for mapping of marble deposits in the vicinity of the ophiolite sequence in North Pakistan.- Marble, a high-pressure and high-temperature metamorphic rock primarily composed of calcium carbonate (CaCO3) and calcium magnesium carbonate (CaMgCO3), has been utilized extensively by ancient civilizations for various architectural purposes globally. The expansion of marble production during the 19th century facilitated its widespread use, with major quarries emerging in various regions, notably China, India, Italy, and Turkey. Despite its historical significance and economic importance, mapping and identifying marble deposits in remote and inaccessible areas remain challenging. This study presents an integrated approach utilizing advanced remote sensing techniques for mapping carbonate lithologies in the Northwest Mohmand District, Khyber Pakhtunkhwa, Pakistan. By employing Advanced Spaceborne Thermal Emission and Reflection Radiometry (ASTER) imaging coupled with Iterative Adaptive Reweighted Regression (IARR), Principal Component Analysis (PCA), Minimum Noise Fraction (MNF) and Spectral Angle Mapper (SAM) classification techniques, we processed and analyzed the ASTER images using the Environment for Visualizing Images (ENVI) software. Subsequently, Geographic Information Systems (GIS), ArcMap, and ArcScene software were used for spatial analysis and model generation. Validation of the results was conducted through extensive fieldwork, X-Ray Diffraction (XRD), and petrographic analysis. The XRD and petrographic data corroborated the findings derived from the classified ASTER imagery, confirming the presence of significant concentrations of dolomite and calcite, which are indicative of carbonate deposits. The integration of these techniques underscores the efficacy of remote sensing as a viable tool for identifying and mapping mineralized zones in remote locations.The findings of this study have significant implications for Pakistan's marble industry, particularly in Khyber Pakhtunkhwa, Punjab, and Baluchistan, where an estimated 300 million tons of marble reserves exist. Leveraging remote sensing techniques, this research contributes to the delineation of valuable marble resources and facilitates recommendations for targeted exploration activities in the Mohmand area and beyond. Mineralogia, vol. 56, no. 1, p. 4-12 Kukula A., Matusiak-Malek M., Mikrut J., Ntaflos T. and Johansson L. (2025).- Syn-volcanic melt-rock reactions recorded in peridotitic xenoliths from Scania, S Sweden. Peridotite xenoliths from Scania (S Sweden), brought to the surface by Mesozoic basanitic magmas, provide insights into the lithospheric mantle underlying the East European Craton. During their ascent, some of the entrained xenoliths were infiltrated by a Si-undersaturated melt. The infiltration triggered orthopyroxene dissolution and the formation of fine-grained olivine, clinopyroxene and Si-rich glasses (trachytic/trachydacitic and dacitic). The latter interacted with clinopyroxene and/or spinel creating spongy rims of various thicknesses (from few to hundreds of ”m). The reactions varied in intensity and effect depending on the distance from the xenolith margin and the duration of the reaction time. At the outer parts of xenoliths, intense reactions dissolved orthopyroxene entirely, forming spongy rims on spinel and clinopyroxene, while inner sections showed limited reactions, primarily between mafic melts and orthopyroxene. The local reheating and melting of fine-grained aggregates during the ascent of xenoliths resulted in the formation of a hydrous, high-Mg, glass-like phase. Carnets Geol., vol. 25, no. 05 Bruno R.C. Granier, Emmanuel Robert & Joanaitz PĂ©rez-Malo.- The Aptian-Albian of the Costa Blanca (SE Spain): Implications for identifying the Aptian/Albian boundary in the neritic zone within the Tethys realm.- The Aptian-Albian interval of the Costa Blanca (SE Spain) has been studied to provide new insights into the evolution of the neritic domain of carbonate platforms in the Tethys. Three areas have been re-examined: Serra Gelada, Puig Campana, and Cabeçó d'Or. The biozonations of large benthic foraminifers (LBF) have been revised based on ammonite biostratigraphy. Updated ammonite datings and stratigraphic revisions reveal that several LBF and calcareous algae (CA) taxa previously attributed to the late Aptian actually originated in the early Albian. These findings correct and refine the calibration of LBF and CA biozones and ranges with standard ammonite zones. Furthermore, the identification of a significant local hiatus during the middle Albian at Cabeçó d'Or is likely linked to halokinesis. Carnets Geol., vol. 25, no. 04 Felix Schlagintweit, Yiwei Xu & Shijie Zhang.- Calcareous green algae (Dasycladales, Halimedaceae) from the Upper Cretaceous of the western Tarim Basin, NW China: Systematic palaeontology, microfacies, and palaeobiogeographic significance.- Few stratigraphical and micropalaeontological data are available from Upper Cretaceous shallow-water marine carbonates of the southwestern Tarim Basin, western China. The present study provides new data about the microfauna and calcareous algae of the Cenomanian-Turonian Kukebai Formation and the Campanian Yigeziya Formation. The investigated bioclastic carbonates yield a rather poorly diversified microfauna (benthic foraminifers) contrasting with a relatively well diversified assemblage of dasycladalean green algae comprising 16 taxa. For several taxa, the available material does only allow for an open taxonomic treatment. A new species is described herein as Morelletpora sinica. These calcareous algae are supplemented by debris of halimedacean algae (Arabicodium? sp.). Occurrences of calcareous algae and larger benthic foraminifers in Cenomanian and Campanian carbonates coincide with two major transgressions reported from the Tarim Basin. The observed faunal and phycological elements indicate a direct connection between the Neotethys and the Tarim epicontinental sea. The lack of several typical Cenomanian (e.g., alveolinoids, orbitolinids) and Campanian larger benthic foraminifers in the studied material is striking. Geologia Acta, vol. 23, no. 1, 29 + XV p. GarcĂa-Penas Ă., Zamora S., Moreno-Bedmar J.A., CalvĂn P. & Aurell M. (2025).- Latest Barremian - early Aptian chronostratigraphy and sedimentary evolution of the northwestern Maestrat Basin.- Some aspects on the age and correlation of the upper Barremian-lower Aptian stratigraphic units of the NW Maestrat Basin were uncertain prior to this study, due to the differing lithostratigraphy of the marginal Oliete subbasin compared to the more depocentral Galve and Morella subbasins. New magnetostratigraphic, ammonite and sedimentological data presented in this study refine the age and sequence stratigraphy of the upper Barremian-lower Aptian succession, enabling a direct and precise correlation across these subbasins. Three third-order TR sequences are identified. The lower boundary of Sequence 1 corresponds to a transgressive surface found on top of the continental red beds of the lower Morella Fm. These beds are equivalent in age to the continental succession of the upper Blesa Fm.(Oliete subbasin). The boundary between the M1 and M0r magnetozones (latest Barremian) is found above this surface, in the lower part of the AlacĂłn Fm. Sequence 1 includes the lower part of the AlacĂłn Fm., which passes basinwards to the upper Morella and Xert formations. Sequence 2 corresponds to the upper part of the AlacĂłn Fm and basinwards to the Cap de Vinyet and Barra de Morella members of the Forcall Fm. The boundary between the M0r and C34n magnetozones (earliest Aptian) is found towards the lowermost part of Sequence 2. Sequence 3 includes the Josa Fm. and its offshore equivalents, the Morella la Vella Mb. and the Villarroya de los Pinares Fm. Additionally, the overall facies distribution in successive depositional stages is reconstructed, describing the lateral transition from marginal protected to open marine areas. The improved chronostratigraphic framework presented here will enable more accurate correlations with other subbasins of the Maestrat Basin, and the reconstructed sedimentary evolution may be useful for the interpretation of other Lower Cretaceous successions of the Tethys. Geologia Acta, vol. 23, no. 2, 25 + XVI p. MarĂn M., Carola E., Beamud E., Bover-Arnal T., LĂłpez-Blanco M., GarcĂ©s M., Roca E., Costa E., Ferrer O. & Cabrera L. (2025).- Paleogene kinematics of the central Catalan Coastal Ranges: temporal constraints from magneto-chronology and provenance analysis in synorogenic deposits in the SE margin of the Ebro Basin (NE Spain).- The precise determination of the tectonic deformation timing such as thrust emplacement has always been a challenge for understanding the evolution of fold-and-thrust belts. In the Catalan Coastal Ranges, this issue has traditionally been addressed through the mapping and the analysis of the syn-tectonic successions preserved in the SE margin of the Ebro Basin. However, the age of the Paleogene contractional structures located towards the hinterland and responsible of the inversion and uplift of the inherited Mesozoic structure remained uncertain due to the lack of preserved syn-kinematic strata in these areas. With the aim of better understand the contractional evolution of the area during the Paleogene, this work presents a tectono-stratigraphic analysis approach that combines structural reconstructions, provenance analysis and magnetostratigraphic dating in well-exposed synorogenic sediments in the central SE margin of the Ebro Basin. The results of the study allow to establish the precise age of the main contractional structures present in the central Catalan Coastal Ranges. The combined analysis has revealed that: i) the inversion of the Montmell-VallĂšs Faults System started in the Bartonian and continued up to the late Priabonian, and ii) the emplacement of the GaiĂ -El Camp Thrust and the formation of the Cabra-Carme Anticline took place from early to late Priabonian and was the responsible of the sudden increased of the sedimentation rates. A later decrease of the sedimentation rates during late Priabonian (chron C15n) has been interpreted as the prelude of the end of the Paleogene compressional phase in the area. Mineralogia, vol. 56, no. 1, p. 1-3 Topolska J. (2025).- Long story encrypted in a small grain â zircon from meta-andesite in the Lower Köli Nappes reveals a complex history of the Virisen Arc Terrane, Scandinavian Caledonides, Sweden.- Tracking trace chemical alterations in biogenic apatite â improvements in tooth sample preparation for experimental approach. Studying the properties of hard tissues, such as bones or teeth, often requires an experimental approach that enables the mechanisms observed in clinical settings to be explained or supports the safe planning of clinical trials. This paper compiles some methodological insights on the proper preparation of biogenic apatite found in human teeth for in vitro studies. These insights were gathered through experimental work and a review of some literature related to in vitro studies on the impact of metal orthodontic appliances on the chemical and crystallographic properties of dental enamel. | |
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