Bioevents and redox conditions around the Cenomanian-Turonian anoxic event in Central Mexico

The Xilitla section of central Mexico (western margin of the proto-North Atlantic) is characterized by pelagic sediments enriched in marine organic matter. Using biostratigraphic and radiometric data, it was dated at the latest Cenomanian-earliest Turonian transition. We identified an interval coeval with the faunal turnover associated with the Oceanic Anoxic Event 2 (OAE 2), recording the Heterohelix shift and thePeer ReviewedPreprin

Redox conditions and authigenic mineralization related to cold seeps in central Guaymas Basin, Gulf of California

Authigenic carbonate crusts, surface muds and bivalve shell fragments have been recovered from inactive and active recently discovered cold seep sites in central Guaymas Basin. In this study, for first time, redox conditions and fluid sources involved in mineral precipitation were investigated by analyzing the mineralogy and textures of surface samples, along with skeletal contents, and C, O and S isotopes variations. The d13C values of aragonitic bivalve shells and non-skeletal carbonate from some surface muds (1‰ to -3.7‰ V-PDB) suggest that carbonate precipitated from ambient dissolved inorganic carbon, whereas fibrous aragonite cement and non-skeletal carbonate from other sites are highly depleted in 13C (down to -47.6‰ V-PDB), suggesting formation via anaerobic oxidation of methane, characteristic of methane seepage environments. d18O in most of the carbonates varies from +1.4‰ to +3.2‰ V-PDB, indicating that they formed from slightly modified seawater. Some non-skeletal carbonate grains from surface muds have lower d18O values (-12.5‰ to -8.2‰ V-PDB) reflecting the influence of 18O-depleted pore water. Size distribution of pyrite framboids (mean value: 3.1¿µm) scattered within diatomaceous sinter suggests formation from anoxic-sulfidic bottom waters. d34S in pyrite is of -0.3‰ V-CDT compared to +46.6‰ V-CDT in barite, thus implying a fluid sulfate-sulfide fractionation of 21.3‰ that argues in favor of microbial sulfate reduction as the processes that mediated pyrite framboid formation, in a semi-closed system. Barite formation occurred through the mixing of reducing and Ba-rich seep fluids with a 34S-enriched sulfate pool that resulted from microbial sulfate reduction in a semi-closed system. The chemical composition of aragonite cement, barite and pyrite suggest mineral precipitation from modified seawater. Taken together, our data suggest that mineralization at the studied seep sites is controlled by the mixing of seawater with minor amounts of hydrothermal fluids, and oxygen-depleted conditions favoring anaerobic microbial processes.Peer ReviewedPostprint (author's final draft

Characteristics and Evolution of sill-driven off-axis hydrothermalism in Guaymas Basin – the Ringvent site

The Guaymas Basin spreading center, at 2000 m depth in the Gulf of California, is overlain by a thick sedimentary cover. Across the basin, localized temperature anomalies, with active methane venting and seep fauna exist in response to magma emplacement into sediments. These sites evolve over thousands of years as magma freezes into doleritic sills and the system cools. Although several cool sites resembling cold seeps have been characterized, the hydrothermally active stage of an off-axis site was lacking good examples. Here, we present a multidisciplinary characterization of Ringvent, an ~1 km wide circular mound where hydrothermal activity persists ~28 km northwest of the spreading center. Ringvent provides a new type of intermediate-stage hydrothermal system where off-axis hydrothermal activity has attenuated since its formation, but remains evident in thermal anomalies, hydrothermal biota coexisting with seep fauna, and porewater biogeochemical signatures indicative of hydrothermal circulation. Due to their broad potential distribution, small size and limited life span, such sites are hard to find and characterize, but they provide critical missing links to understand the complex evolution of hydrothermal systems

Microfacies analysis and paleoenvironmental dynamic of the Barremian-Albian interval in Sierra del Rosario, eastern Durango state, Mexico

The detailed microfacies analysis on a stratigraphic section located in eastern Durango contribute to the paleoenvironmental and paleogeographic understanding of the Cupido and Coahuila carbonate platforms in the southern part of the Coahuila basement block, a poorly investigated area. The stratigraphic section herein studied spans the Barremian-Albian interval and is composed of the upper Cupido, La Peña and Upper Tamaulipas formations. The recognition of this latter unit in the eastern part of the Durango state is a significant contribution to the stratigraphic scheme of the southern part of the Sierra del Rosario. The studied interval of the Cupido Formation is represented by different microfacies associations: 1) peritidal and subtidal facies deposited in a shallow lagoon. In these facies, an important microbial contribution and high energy events are recognized; 2) sand bars facies accumulated on the platform margin. Interaction of these facies with sea level fluctuations caused different levels of restriction and periodic flooding in the platform interior; 3) platform margin and fore-reef facies. The microfacies associations of the La Peña Formation were deposited on the periplatform zone in an outer neritic to upper bathyal environment. The microfacies associations of the upper part of the La Peña Formation and those belonging to the Upper Tamaulipas Formation are typical of open marine and relatively deepwater conditions. The microfacies have been divided according to their relation with the different phases of the Cupido Platform drowning. The definitive drowning phase began in the early Aptian when the sea level rose over the sand shoals on the platform margin. An increase in the crinoid content and a mixture of lagoonal and open marine biota are characteristics of the drowning phase at the end of the Cupido Formation deposition. The microfacies associations within the lower part of the La Peña Formation recorded the definitive drowning of the platform and an environmental stress that accentuated this event. Post-drowning facies in the upper part of the La Peña Formation and throughout the Upper Tamaulipas Formation are represented by pelagic facies deposited in an open marine environment with significant oxygen variations in the water-sediment interface. The sand shoals facies described in the Cupido Formation correspond to the western continuation of the Barremian-Aptian Cupido Platform margin.El análisis detallado de microfacies de una sección estratigráfica localizada en el este del estado de Durango aporta importante información paleoambiental y paleogeográfica sobre las plataformas estudiada. La sección estratigráfica comprende el lapso Barremiano-Albiano y está compuesta por la parte superior de la Formación Cupido y las formaciones La Peña y Tamaulipas Superior. El reconocimiento de esta última unidad en el este del estado de Durango es una contribución significativa al esquema estratigráfico de la porción sur de la Sierra del Rosario. El intervalo analizado de la Formación Cupido comprende diferentes asociaciones de microfacies: 1) facies lagunares perimareales y submareales, en algunas de las cuales se reconoce un importante aporte microbiano y facies relacionadas con eventos de alta energía; 2) facies de barras arenosas en la margen de la plataforma, cuya interacción con las fluctuaciones del nivel del mar causaron diferentes niveles de restricción en el interior de la plataforma e inundaciones periódicas; 3) facies de margen de plataforma y del frente arrecifal. Las asociaciones de microfacies de la Formación La Peña fueron depositadas en una posición de periplataforma en la zona nerítica externa a batial superior. Las asociaciones de microfacies de la parte superior de la Formación La Peña y las correspondientes a la Formación Tamaulipas Superior son propias de ambientes marinos abiertos relativamente profundos. A partir de los rasgos de las microfacies se discriminaron las asociaciones relacionadas con cada fase del ahogamiento de la Plataforma Cupido. El ahogamiento definitivo ocurrió a inicios del Aptiano cuando el nivel del mar superó las barras arenosas en la margen de la plataforma. El aumento de crinoideos y la mezcla de biota lagunar y de condiciones marinas abiertas caracterizan la fase de ahogamiento al término del depósito de la Formación Cupido. Las asociaciones de microfacies de la parte inferior de la Formación La Peña denotan el ahogamiento definitivo de la plataforma y registran un estrés ambiental que terminó de acentuar este evento. Las facies posteriores al ahogamiento, en la parte superior de la Formación La Peña y en la Formación Tamaulipas Superior, son facies pelágicas depositadas en una zona con circulación libre al océano abierto y variaciones significativas en el contenido de oxígeno en la interfase sedimento-agua. Las facies de barras arenosas descritas en la Formación Cupido corresponden a la prolongación más al oeste de la margen sur de la Plataforma Cupido durante el Barremiano-Aptiano

Análisis mineralógicos, petrográficos y geoquímicos confirman el origen hidrotermal de sedimentos metalíferos sobreyaciendo las peridotitas de Cerro Matoso, Colombia

The Cerro Matoso deposit, one of the largest open-pit ferronickel mines in the world is formed by a sedimentary succession on top of an abducted ultramafic body that makes part of the Cauca ophiolite complex. The set of rocks was accreted in northwestern Colombia during the Cretaceous and exposed to weathering processes during the last Andean Orogeny. Sediment samples were collected and studied using petrographic microscopy, SEM, EPMA, ICP-MS, XRF, and oxygen as well as carbon isotopes analyses. Oxygen isotope results reflect pore-water temperatures reaching up to 130°C during mineral precipitation, which are consistent with serpentinization-derived fluids of mantle rocks that may be related to deep-sea hydrothermal activity. Negative δ13C values (–27.1 to –1‰ V-PDB) in bulk samples of the tabular succession correlate with the δ13C range of methane from modern serpentinite-derived fluids. The REE/Fe data (ratio <0.4) suggest that sediments differenced in black mudstone and fossiliferous green claystone correspond to metalliferous and hydrothermal sediments respectively, formed in the ancient mid-ocean Pacific ridge, far west of its present position. Positive Eu and negative Ce anomalies registered in the black mudstone succession correlate with a hydrothermal plume scenario.[ES] El yacimiento Cerro Matoso, una de las minas de ferroníquel a cielo abierto más grandes del mundo, está formado por una sucesión sedimentaria que reposa sobre un cuerpo ultramáfico adosado al continente, que forma parte del Complejo Ofiolítico del Cauca. El conjunto de rocas fue adosado en el noroeste de Colombia durante el Cretácico, y fue expuesto a procesos de meteorización durante la última orogenia andina. Las muestras de sedimentos fueron recolectadas y estudiadas mediante microscopía petrográfica, SEM, EPMA, ICP-MS, FRX y análisis de isótopos de oxígeno y carbono. Los resultados de los isótopos de oxígeno reflejan temperaturas del agua intersticial que alcanzan los 130°C durante la precipitación mineral, lo que es coherente con fluidos derivados de la serpentinización de las rocas ultramáficas que pueden estar relacionados con actividad hidrotermal en el fondo del mar. Los valores negativos de δ13C (−27,1 a −1‰ V-PDB) en muestras (roca total) de la sucesión sedimentaria, se correlacionan con el rango de δ13C del metano de fluidos modernos derivados de serpentinita. Los datos REE/Fe (relación <0.4) sugieren que los sedimentos denominados lodolitas negras y arcillolitas verdes fosilíferas corresponden a sedimentos metalíferos e hidrotermales respectivamente, formados en la antigua dorsal meso-oceánica del océano Pacífico, muy al oeste de su posición actual. Las anomalías positivas de Eu y negativas de Ce registradas en la sucesión de lodolitas negras se correlacionan con un escenario de plumas hidrotermale

Bioevents and redox conditions around the Cenomanian-Turonian anoxic event in Central Mexico

The Xilitla section of central Mexico (western margin of the proto-North Atlantic) is characterized by pelagic sediments enriched in marine organic matter. Using biostratigraphic and radiometric data, it was dated at the latest Cenomanian-earliest Turonian transition. We identified an interval coeval with the faunal turnover associated with the Oceanic Anoxic Event 2 (OAE 2), recording the Heterohelix shift and thePeer Reviewe

Apunte geológico y revisión histórica de la zona geotérmica de Pathé, Hidalgo

La zona geotérmica de Pathé, en el sector oriental de la Faja Volcánica Transmexicana, ha atraído la atención de exploradores y científicos desde finales del siglo XVIII. El ingeniero de minas alemán Joseph Burkart (1798-1870), discípulo de Alexander von Humboldt (1769-1859), elaboró en 1836 una detallada descripción geológica de la zona, gracias a la cual esta zona geotérmica fue la primera en México en investigarse bajo los paradigmas de la ciencia moderna. A inicios del siglo XX la zona fue estudiada por el ingeniero José Guadalupe Aguilera Serrano (1857-1941), quien en 1907 describió las rocas eruptivas y sus productos de alteración. Su interés eran los yacimientos de caolín de Yexthó, situados a un km de las manifestaciones de termales. A mediados de siglo la zona ya se prospectaba como fuente de energía geotérmica, lo que culminó en la primera planta geotermoeléctrica del continente americano, en operación entre 1959 y 1972 con una capacidad nominal de 3.5 MW. Las manifestaciones termales de Pathé se ubican en la intersección de dos sistemas regionales de fallas, de dirección N-S y E-W, y están encajonadas en una unidad volcánica (toba y lava) de composición básica a intermedia y edad Mioceno superior. Las alteraciones hidrotermales superficiales son conspicuas y su distribución está igualmente controlada por fallas pertenecientes a ambos sistemas. Asociada a las fallas N-S ocurre la asociación de alteración calcita-yeso, que involucra fluidos oxidados y alcalinos. Por otro lado, ligados a las fallas E-W ?más tardías? se hallan los depósitos de caolín, producto de una alteración argílica avanzada, característica de zonas de condensación de vapor. Las condiciones del fluido indicadas por esta alteración son un pH muy ácido (2–3) y temperaturas cercanas a los 100 °C. Por su clara asociación con las fallas, así como por la ausencia de vulcanismo reciente (Cuaternario) cercano, Pathé se clasifica como un sistema geotérmico convectivo controlado por fallas. La sucesión de eventos de alteración sugiere que la actividad hidrotermal inició desde antes del Plioceno. doi: https://doi.org/10.22201/igeof.00167169p.2021.60.3.213

Thermal history of the Sabinas - Piedras Negras Basin (Northeastern Mexico): Insights from 1D modelling

International audienceThe thermal and burial history of the Sabinas-Piedras Negras basin was studied by 1D modelling using vitrinite reflectance values measured on core samples from nine wells. Three heat flow scenarios led to model calibrations, including a simple one and a complex one integrating a thermal anomaly following the maximal burial phase. The differences in hydrocarbon generation curves due to these two scenarios were studied. The studied thermal anomaly induces two distinct phases of primary cracking of kerogen. The first phase is clearly due to burial, whereas the second seems to be due to the thermal event. The increase in the proportion of converted organic matter attributed to this second phase varies depending on the source rocks considered, e.g., for the La Casita source rock, there is a 10% TR increase, whereas that of the La Peña and Eagle Ford source rocks, is 35 and 15% respectively. The thermal evolution of organic matter in the Sabinas-Piedras Negras Basin is mainly due to the burial phase. In contrast, the thermal event considered only causes a temporal shift of hydrocarbon generation. This hydrocarbon generation, primordially gas, occurred mainly before and during the compressive phase ("late Laramide" time step 40-35 Ma [middle-late Eocene]) that affected the Sabinas-Piedras Negras Basin

Paleoenvironment and source-rock potential of the Cenomanian-Turonian Eagle Ford Formation in the Sabinas basin, northeast Mexico

The Cenomanian-Turonian Eagle Ford Formation is a widespread organic-rich mudrock in Texas and northern Mexico. The economic significance of this unit for oil and gas production in USA has led to numerous investigations documenting its lithological and geochemical variability. Comparatively little is known about facies distribution and source rock potential of this unit in Mexico. Here, we studied a section of the Eagle Ford Formation in the central part of the Sabinas basin. In order to evaluate the lateral continuity of the Eagle Ford Formation, and more specifically to gain understanding of the paleoenvironmental drivers of organic matter deposition and the hydrocarbon source source rock potential of this unit, we combined lithological, gamma-ray spectrometric, petrographic and organic geochemical data. Vertical distribution of main lithologic units and gamma-ray signal of the Eagle Ford Formation of the studied section match those documented in several sites from Texas, with the shale-dominated, bentonite-rich succession of the lower Eagle Ford showing the higher gamma-ray values, and the limestone-dominated succession of the upper Eagle Ford exhibiting moderate-high gamma ray values. Th/K and U/Th ratios suggest that the organic-rich lower Eagle Ford was deposited mainly during a warmer and more humid period, probably related to a sub-humid regional climate phase during the Cenomanian-Turonian global warming event, and under anoxic/dysoxic marine environments. Furthermore, a higher abundance of radiolarians indicates its deposition under nutrient-rich surface water conditions induced by upwelling currents. In contrast, these ratios support a less humid climate and oxic/dysoxic conditions during the accumulation of the upper Eagle Ford. Nevertheless, fluctuations of bottom water oxygen are evidenced by the occurrence of high TOC contents and bioturbated levels. Although TOC values throughout the Eagle Ford Formation point to a poor to very good source rock potential, both equivalent vitrinite reflectance (%VReq) and Tmax values indicate that the organic matter is overmature and has an exhausted hydrocarbon generation capability.This research was funded by CONACyT (Consejo Nacional de Ciencia y Tecnología) Ciencia Básica grant number A1-S-18123 to Fernando Núñez-Useche.Peer reviewe

Femoral Head Bone vs Acetabular Subchondral Bone: Selecting the Optimal Anatomical Site to Obtain Mesenchymal Stromal Cells from Human Bone Marrow for Regenerative Medicine. Short Communication

Background: Mesenchymal Stromal Cells (MSC) have a great importance for the field of regenerative medicine. However, there is high variability in existing protocols for MSC in vitro expansion, which can lead to low reproducibility of pre-clinical studies and, even more critically, the reduced safety of patients undergoing clinical trials. Although bone marrow is one of the most important sources for the isolation and in vitro culture of MSC, the preferred anatomical location for obtaining bone marrow is often unclear, and this information is relevant for the interpretation of results obtained from preclinical and clinical trials. Methods: In this study, we compared various biological characteristics of human MSC obtained from five total hip replacement surgery donors isolated from the bone marrow of two different anatomical sites: the femoral head bone (Fh) and the acetabular subchondral bone (Ac). Using the same surgical technique and collection volume, we compared the morphological characteristics, fibroblast colony forming unit (CFU-F) capacity, immunophenotype, capacity for differentiation (osteogenesis, condrogenesis, and adipogenesis) and population doubling time (PDT) of MSC isolated from these distinct anatomical locations. Results: Here, we show that human MSC isolated from Fh have improved morphological and proliferative characteristics that are associated with higher in vitro efficiency for regenerative medicine protocols compared with cells obtained from Ac. Conclusion: This report provides information regarding the importance of establishing a "standard" anatomical site for obtaining bone marrow as one of the most important requirements of the "preanalytical" phase of MSC in vitro expansion for regenerative medicine.https://orcid.org/0000-0003-2436-5621https://orcid.org/0000-0003-0157-3639https://orcid.org/0000-0002-3899-8406https://orcid.org/0000-0003-1881-9367Revista Internacional - No indexadaN