FLUVIAL LIMESTONE TUFFS FROM THE S. PORTUGAL (LOULE-TAVIRA) AND N. MOROCCO (TETUAN): COMPARISON AND ENVIRONMENTAL IMPLICATIONS

Limestone tuff deposits precipitated in fluvial environments are widespread in the northern Morocco and the S Portugal. These deposits represent environmental conditions prone for the carbonate precipitation mainly in areas of Mesozoic limestone substratum with active water seepage from the aquifers. The mesoscopic and microscopic characteristics of tuff deposits from Tetouan (Morocco) and Loule and Tavira (Portugal) are very alike; namely on deposit types (e.g. phytoherm barriers; banded limestones with abundant vegetation macro-remains; carbonates precipitation as cement of some early alluvial conglomerates or interbedded alluvial deposits). The common textural features and macro-facies (e.g. banded calcite in regular layers ; moldic porosity; textures resulting from carbonate precipitation mediated by bacteriological activity) point to a similar origin of these limestone tuffs on both sides of Gibraltar Strait despite their slightly different climatic conditions that are influenced by the active inflow of surface Atlantic water towards the Mediterranean (for the Tetouan region) and by the Azores anticyclone (for the Loulé-Tavira region). The field observations show that the limestone tuffs precipitation is nowadays residual and radiocarbon dating of Portuguese deposits points to a chronological framework for their formation starting in the beginning of the post-Younger Dryas climatic recovery and ending around 2.5 ky BP. The oxygen stable isotopes data show a gradual change in the tuffs isotopic signature through the time interval during which the system remained active, without any particular record of climate events such as the 8.2 ka. The available data and those from monitored modern pluvial characteristics allow the speculation on the parameters controlling the limestone tuffs deposition on both northern and southern sides of the Gibraltar Strait during the Holocene. The carbonate deposition on fluvial systems, such as the studied ones, probably depends on the precipitation / evaporation balance leading to the availability and turbulence of the flowing water along the streams. Acknowledgments: This works was done with the financial support of the FCT Proc. 441.00 CNRST- MARROCOS and PTDC/CTE-GIX/117608/2010 projects and the SFRH/BD/62323/2009 grant

Tectonic evolution of the ‘Liguride’ accretionary wedge in the Cilento area, southern Italy: A record of early Apennine geodynamics

International audienceThe early stages of southern Apennine development have been unraveled by integrating the available stratigraphic record provided by synorogenic strata (of both foredeep and wedge-top basin environments) with new structural data on the Liguride accretionary wedge cropping out in the Cilento area, southern Italy. Our results indicate that the final oceanic subduction stages and early deformation of the distal part of the Apulian continental margin were controlled by dominant NW-SE shortening. Early Miocene subduction-accretion, subsequent wedge emplacement on top of the Apulian continental margin and onset of footwall imbrication involving detached Apulian continental margin carbonate successions were followed by extensional deformation of the previously 'obducted' accretionary wedge. Wedge thinning also enhanced the development of accommodation space, filled by the dominantly siliciclastic Cilento Group deposits. The accretionary wedge units and the unconformably overlying wedge-top basin sediments experienced renewed NW-SE shortening immediately following the deposition of the Cilento Group (reaching the early Tortonian), confirming that the preceding wedge thinning represented an episode of synorogenic extension occurring within the general framework of NW-SE convergence. The documented Early to the Late Miocene steps of southern Apennine development are clearly distinct with respect to the subsequent (late Tortonian-Quaternary) stages of fold and thrust belt evolution coeval with Tyrrhenian back-arc extension, which were characterized by NE-directed thrusting in the southern Apennines

The age of the foredeep sedimentation in the Betic-Rifian Mauretanian Units: A major constraint for the reconstruction of the tectonic evolution of the Gibraltar Arc.

In the Gibraltar Arc, the age of the turbiditic formations capping the Mauretanian successions, deposited in the internal side of the Maghrebian Flysch Basin Domain and testifying to the foredeep stage of the basin occurring immediately before its deformation, has been re-examined using the calcareous nannoplankton. The base of the successions resulted to be not older than Chattian or Early Miocene, whereas the top is not older than Late Burdigalian. Therefore, the foredeep evolution and the deformation of the Mauretanian Sub-Domain started not before the Late Oligocene and the Late Burdigalian, respectively, and the Iberia-Africa collision occurred as from the Middle Miocene

Sedimentary evolution of Quaternary tufas and travertines (Tetouan-Northern Morocco): implications for earth processes and depositional systems.

The continental carbonates, such as travertine and tufa, are among the sediments recording climate change manly during Quaternary times. Their lithofacies and petrofacies are useful for understanding the related hydrologic, geomorphologic and climatic processes as well as the depositional palaeoenvironments. Thus, the present work deal with the analysis and interpretation of the main facies association of Tetouan city travertine cliffs and terraces. According to morphologic, sedimentologic and petrographic investigations coupled with 1/5000 scale mapping, four main facies associations were recognized and show from the top to bottom: i) barrage and cascade limestones, ii) base of the cascade limestone breccias and blocks, iii) lacustrine detrital deposits and iv) carbonate pedogenic crusts. The barrage facies associationis characterized by carbonate deposits with a wide textural features: a) massive micritic limestone, b) brecciated limestone with remnants of calcified leaves, stems of macrophytes and fresh-water gastropods, c) thin-layered calcite sheets (probably corresponding to ancient algal mats) or calcite layers to remnants of herbaceous plants, d) soft black pocket marls with remnants of calcified leaves, stems and mollusks (i.e. terrestrial and fresh-water gastropods). The base of the cascade facies association, located at the east and the central part of the escarpment, is made of fallen blocks detached from the carbonate build-up that constitutes the dam that are embedded in multi-colored crystalline travertine bands. The third facies association is constituted by detrital sediment strata with an obvious contribution from barrage and cascade limestones mainly supplied from the Dorsal calcaire relieves mainly made of calcacareous plateform deposits The fourth facies association correspond mainly to pedogenic carbonate crusts usually topping outcrops of lacustrine sediments, but also present in erosive surfaces or within cascade limestones. Vertical NNE-SSW fracture sets are found in the Oued Martil slope, fulfilled by carbonate crust-like material. Tetouan travertine petrofacies are mainly represented by: i) rolled crusts made of different morphological types: cylindrical, oncholites, flat and corrugated crystallized around various nucleus. ii) detrital fine to medium grained calcareous sands, iii) homogenous micritic facies with primary precipitation of micrite during periods of low flow velocities and calm waters and probably in relation to microbial activities, iv) micrite-coarse banded crystalline sheets consist of palisade calcite crystals related to cyclic changes in chemical, physical and/or environmental conditions or even diurnal cycles of microbial activity. In addition, this study has highlighted that Tetouan travertines may have formed under strong hydrodynamic environments within rapid water flow waterfalls intercalated with slower flow and calm waters periods. These travertines may also record the occurrence of seasonal climatic variations related to microclimatic fluctuation during part of the Holocene. In Southern Portugal the same type of Holocene terrestrial carbonate deposits, exhibit similarities in the petrofacies observed and in the facies association. A smaller urban coverage allows a detailed observation of the outcrops showing the existence of active and fossil incrusting systems fed by the Jurassic aquifers

Galantamine ameliorates hyperoxia-induced brain injury in neonatal mice

Introduction: Prolonged oxygen therapy in preterm infants often leads to cognitive impairment. Hyperoxia leads to excess free radical production with subsequent neuroinflammation, astrogliosis, microgliosis and apoptosis. We hypothesized that Galantamine, an acetyl choline esterase inhibitor and an FDA approved treatment of Alzheimer’s disease, will reduce hyperoxic brain injury in neonatal mice and will improve learning and memory. Methods: Mouse pups at postnatal day 1 (P1) were placed in a hyperoxia chamber (FiO2 95%) for 7 days. Pups were injected IP daily with Galantamine (5 mg/kg/dose) or saline for 7 days. Results: Hyperoxia caused significant neurodegeneration in cholinergic nuclei of the basal forebrain cholinergic system (BFCS), laterodorsal tegmental (LDT) nucleus and nucleus ambiguus (NA). Galantamine ameliorated this neuronal loss. Treated hyperoxic group showed a significant increase of choline acetyl transferase (ChAT) expression and a decrease of acetyl choline esterase activity, thus increasing acetyl choline levels in hyperoxia environment. Hyperoxia increased pro-inflammatory cytokines namely IL -1β, IL-6 and TNF α, HMGB1, NF-κB activation. Galantamine showed its potent anti- inflammatory effect, by blunting cytokines surges among treated group. Treatment with Galantamine increased myelination while reducing apoptosis, microgliosis, astrogliosis and ROS production. Long term neurobehavioral outcomes at P60 showed improved locomotor activity, coordination, learning and memory, along with increased hippocampal volumes on MRI with Galantamine treated versus non treated hyperoxia group. Conclusion: Together our findings suggest a potential therapeutic role for Galantamine in attenuating hyperoxia-induced brain injury. Copyright © 2023 Zaghloul, Cohen, Ayasolla, Li, Kurepa and Ahmed.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]