Search Results (9)

The Onil and Ibi sections (Prebetic Zone, Betic Cordillera: Alicante, SE Spain) record a late Ypresian (Cuisian) to early Lutetian (~51 to ~43 Myr) carbonate platform succession, dated using larger benthic foraminifera (LBF) and planktonic foraminifera. Seven field lithofacies (L1 to L7) and five thin-section microfacies (Mf1–Mf5) were identified, indicating inner- to mid-ramp environments (from seagrass meadows to Maërl-LBF-dominated) in warm-water and low-latitude conditions. A distinctive feature of these platforms is their dominance by LBF in association with rhodophyceae, contrasting with typical coral reef factories. We propose a novel carbonate production model, “TC-factory”, to describe these warm-temperate systems. Integrated field logging, drone imagery, and microfacies data allowed us to define a sequence stratigraphic framework comprising five lower-frequency sequences (LFS: ~2 Myr average duration), each of them nesting various numbers of high-frequency sequences (HFS: ~0.25 to ~1 Myr). The LFSs belong to a higher-rank sequence bounded by regional unconformities. The five LFSs only broadly match the upper Ypresian and lower Lutetian cycles in global eustatic curves (~51 to ~43 Myr), indicating that other regional or local controls were important. The number of HFSs being fewer than expected also suggests additional controls, such as local tectonics, erosion during lowstands, or carbonate production feedback. Full article

The middle and upper Eocene sedimentary successions exposed along the northwestern and northeastern portions of the Nile Valley, Egypt, have been thoroughly examined for their ostracod assemblages. This study enhances the understanding of biostratigraphic zonations and evaluates the paleobiogeographic distribution and paleoenvironmental conditions that prevailed during the deposition of this sedimentary record. Lithostratigraphically, the studied successions are subdivided into four stratigraphic units, arranged in ascending order as follows: the Qarara, the El Fashn, the Gehannam, and the Beni Suef formations. A total of 125 rock samples were selected and well analyzed, resulting in the identification of sixty-five ostracod species and subspecies belonging to thirty-three genera, fifteen families, and three superfamilies. The stratigraphic distribution of the recorded ostracod taxa contributed to the construction of four local biozones, spanning the interval from the upper Lutetian to lower Priabonian: Schizocythere fadlensis Zone (upper Lutetian–lower Bartonian), Loxoconcha pseudopunctatella Zone, Dygmocythere ismaili Zone (Bartonian), and Asymmetricythere hiltermanni Zone (Bartonian–Priabonian). These biozones are well described, discussed, and correlated with those previously documented in different areas of Egypt and neighboring countries. The statistical analysis, supported by ternary plot diagrams, indicates that the depositional environments of the studied rock units fluctuated between shallow inner neritic and deeper outer neritic marine environments. The identified taxa display a wide geographic distribution and show a significant similarity with those identified in the southern, northern, and eastern Tethyan provinces, suggesting a direct marine connection during the Eocene. Full article

This study deals with the biostratigraphic determination and paleoenvironmental reconstruction of the middle–upper Eocene sediments along the northwestern and northeastern banks of the Nile Valley, Egypt. The studied successions are classified into four rock units as follow: The Qarara (Lutetian–Bartonian), the El Fashn (Bartonian), the Gehannam, and the Beni Suef (Bartonian–Priabonian) formations. A total of eighty planktonic foraminifera species belonging to twenty-two genera and eight families are identified, and their vertical distribution enabled us to recognize four planktonic biozones, namely the Morozovelloides lehneri Zone (late Lutetian–early Bartonian), Orbulinoides beckmanni Zone (early Bartonian), Morozovelloides crassatus Zone (late Bartonian), and Globigerinatheka semiinvoluta Zone (late Bartonian–early Priabonian). The faunal assemblages characterizing these zones showed a great similarity with those recorded in the lower latitudes (tropical and sub-tropical) regions and correlated with the planktonic zones in the northern and southern Tethyan provinces. The appearance of Orbulinoides beckmanni distinguishes the early Bartonian period, its lowest occurrence defines the upper boundary of the Morozovelloides lehneri Zone, and its highest occurrence marks the lower boundary of the Morozovelloides crassatus Zone. The disappearance of the spinose forms of morozovellids and the large acarininids, besides the highest occurrence of Morozovelloides crassatus, defines the lower boundary of the Globigerinatheka semiinvoluta Zone. The middle/upper Eocene boundary is traced based on the last and first appearance of the marker planktonic species and located herein within the Globigerinatheka semiinvoluta Zone. The paleontological data, including the planktonic to benthic foraminiferal ratio (P/B), statistical analyses of different foraminiferal groups, and ternary plot diagrams in conjunction with the sedimentological features, indicate changes in the depositional settings, fluctuating between the inner to middle and outer neritic environment and the uppermost bathyal environment at some levels. Full article

Two brachiopod species, Terebratulina tenuistriata (Leymerie, 1846) and Orthothyris pectinoides (von Koenen, 1984), have been recorded for the first time from the Middle Eocene (Late Lutetian) nummulitic limestone beds in the Darnah Formation at the Wadi Darnah area in Northeast Libya. These brachiopod species are associated here with Nummulites discorbinus (Schlotheim), Nummulites praelyelli (Boukhary and Kamal), and Nummulites bullatus (Schaub) and are widely distributed on this Middle Eocene Nummulites carbonate platform. The two recorded species are common in the Eocene rocks of Europe and the Arabian Gulf. In northern Africa, the brachiopod species Terebratulina tenuistriata (Leymerie) was only recorded from the Middle Eocene (Bartonian) of Egypt, while Orthothyris pectinoides (von Koenen) is firstly recorded from the Middle Eocene of the southern Tethyan Province (NE Libya) in the present work. Full article

The Eocene deposits of Egypt provide a wide variety of shallow marine facies and fossil assemblages, allowing paleoenvironmental reconstructions in this warmhouse climate interval. Forty-three rock samples have been collected from two middle Eocene sections, exposed at southeast Beni-Suef area in northern Egypt. The studied outcrops are lithologicsally subdivided into two rock units named from base to top as follows: (1) the Qarara Formation (Lutetian) and (2) the El Fashn Formation (Bartonian). Most investigated rock samples showed richness in benthic foraminiferal assemblages and only rare occurrences of index planktonic foraminifera. They yielded 160 foraminifera species which belong to 4 suborders, 19 superfamilies, 34 families, and 59 genera. The stratigraphic distribution of the identified species allowed us to define four local benthic bio-ecozones: (1) Bolivina carinata Lowest Occurrence Zone (Lutetian), (2) Cibicides mabahethi/Cancris auriculus primitivus Concurrent-Range Zone, (3) Nonion scaphum Lowest Occurrence Zone, and (4) Brizalina cookei/Nonionella insecta Concurrent-Range Zone (Bartonian). These biozones are described and discussed in detail and correlated to stratigraphic equivalents in Egypt. The rareness of index planktonic foraminifera through the studied sections does not allow a precise biostratigraphic and chronostratigraphic correlation. The shale samples show low TOC values, which may be related to low productivity, high sediment influx, and/or prevailing oxic conditions. Bulk rock geochemistry, consistent with the benthic foraminifera ecological preferences, indicated that the studied sections were deposited in moderate to high oxygen levels and warm climatic conditions in a typical shelf marine setting. The identified species showed strong similarities with nearby southern Tethys areas, reflecting migration via the trans-Sahara seaway, and minor similarities with those identified from the northwestern Tethys and the North Atlantic province attributed to the change in the environmental and climatic conditions, such as cooler, latitudinal zoned climatic conditions along the northwestern Tethys, which was unsuitable for their biological demands. The warming trend identified from Lutetian to Bartonian intervals corresponds to the onset of the Middle Eocene Climatic Optimum (MECO). Full article

Turtle shells frequently exhibit anomalous osseous modifications on their surface which can sometimes compromise the survival of the organism. Nowadays, despite the large number of anomalies identified in both extant and extinct turtle shells, the etiology, as well as the pathogenesis, of the various osseous modifications remains unknown in most documented extinct representatives. In fact, the interpretation of these anomalies in most fossil turtles is often speculative, the great majority of anomalous osseous modifications being attributed to vertebrate feeding traces, without considering other potential causative agents. In this context, we herein re-analyzed the shell anomalies recognized in an individual determined as Neochelys sp. (Pleurodira, Podocnemididae) from the middle Eocene (Lutetian) of the El Tejar fossil site (Corrales del Vino, Zamora, Spain), previously proposed as traumatic injuries resulting from a crocodile attack. The re-evaluation of these osseous alterations through detailed physical examination, comparison through direct observation and from the literature on extant turtles, and the use of the files obtained from a computerized axial tomography scan, allows the proposal of diverse causal agents, none of them supporting the previous interpretation. In addition, information regarding the pathogenesis and stages of the healing of the shell anomalies studied herein is provided. Full article

This work proposes sustainability criteria for the selection or design of restoration mortars based on their physical and mechanical properties, durability, price in the French market, and the environmental impact estimated by the global warming potential. A score is assigned to the mortars based on normalized values of their physical and mechanical properties. A total of 24 formulations of restoration mortars were characterized, and their scores were compared. A case study showing the application of the proposed selection method is presented, focused on the restoration of historical monuments in Paris, France, built with Lutetian and Euville stones. In this case, hydraulic lime mortars were the most sustainable options. The application of the method is also projected for global application, as showcased for the restoration of Mayan stones in Southern Mexico. Full article

Discrete zircons, up to 9 mm in length, occur in alluvial deposits from the Veneto area. They are likely derived from the disaggregation of lamprophyric rocks belonging to a regional, pervasive dyke-swarm. Zircon and REE phases occur in both alkaline lamprophyres and connate calcite-bearing felsic lithics and their debris in lamprophyre breccia. We present 36 new complete U–Pb and trace element analyses of zircons and associated inclusions. We used a statistical approach on a larger dataset using new and literature data to evaluate the confidence figure to give an estimation of age of zircons. Inclusions suggest a genetic link with an S–CO₂–ZrO–BaO–SrO–CaO-rich fluid/melt possibly associated with carbonate-rich alkaline parental magma and a metasomatised mantle source. This paper confirms the importance of calcite–syenite and lamprophyre genetic link and zircon magmatic origin, in contrast with hydrothermal and metamorphic zircons. U–Pb dating by LA-ICP-MS provides time constrains (40.5–48.4 Ma, Lutetian), consistent with the age of the alkaline magmatic event. Trace element data indicate a link to anorogenic magmatism associated with mantle upwelling. Complex zoning is highlighted by cathodoluminescence images. The Veneto zircons are helpful for regional geological information and may have commercial potential as a critical resource for green technologies. Full article

The biostratigraphy of the Outer Carpathians is based mainly on the ranges of agglutinated foraminifera. Species acmes provide the opportunity to enhance and support the existing biozonations. Assemblages of agglutinated foraminifera from the Campanian to Eocene of various tectonic-structural units were analyzed in terms of their qualitative and quantitative occurrence. In this stratigraphic interval, 19 species display significantly increased abundance within a relatively short interval: Caudammina gigantea (Geroch) (upper Santonian–lowermost Maastrichtian), Caudammina ovulum (Grzybowski) (Campanian–Danian), Placentammina placenta (Grzybowski)-Saccammina grzybowskii (Schubert) (upper Campanian–Danian), Caudammina excelsa (Dylążanka) (lowermost Maastrichtian–Danian), Caudammina ovuloides (Grzybowski) (Danian–Selandian), Hormosina velascoensis (Cushman) (upper Danian–Selandian), Praesphaerammina gerochi (Hanzlíková) (Thanetian), Glomospira charoides (Jones et Parker)-Glomospira gordialis (Jones et Parker) (uppermost Thanetian–lowermost Ypresian), Trochammina spp. (upper Thanetian–lower Ypresian), Reticulophragmium amplectens (Grzybowski) (Lutetian–Bartonian), Reophax duplex (Grzybowski)-Reophax “pilulifer” Brady group of taxa (Lutetian–Priabonian), Haplophragmoides walteri (Grzybowski)-Haplophragmoides nauticus Kender, Kaminski et Jones (Lutetian–Bartonian), Spiroplectammina spectabilis (Grzybowski) (Lutetian–Priabonian), “Ammodiscus” latus Grzybowski (Bartonian–Priabonian), Praesphaerammina subgaleata (Vašíček) (Lutetian–Bartonian). The biostratigraphic position and quantitative data of species with increased abundance are presented. Full article