UPPER TRIASSIC CALCAREOUS ALGAE FROM THE PANTHALASSA OCEAN

Upper Triassic calcareous algae, abundant and well-diversified in Tethyan deposits, have rarely been described in rocks of Panthalassan origin. Over the past ten years, several studies were performed on Upper Triassic carbonate deposits of Panthalassan affinity in North America, Japan and Far East Russia, revealing unexpectedly rich and diversified assemblages. The samples were collected from nine localities situated on both sides of the Pacific Ocean. The identified algal assemblage consists of green and red algae, including fourteen dasycladaleans, rare bryopsidaleans, and several rhodophyceans. This paper describes the main algal taxa, including six new species: Holosporella? rossanae Bucur & Del Piero n. sp., Holosporella magna Bucur & Fucelli n. sp., Griphoporella minuta Bucur & Peybernes n. sp., Patruliuspora pacifica Bucur, Del Piero & Peyrotty n. sp., Patruliuspora oregonica Bucur & Rigaud n. sp. and Collarecodium? nezpercae Bucur & Rigaud n. sp. Rivulariacean-like cyanobacteria and thaumatoporellacean algae are also present. The whole Panthalassan algal assemblage comprises both unknown (?endemic) and common taxa of the Tethyan domain. To explain the cosmopolitan distribution of various Upper Triassic benthic organisms scleractinian corals, calcified sponges, foraminifera), a close connection with the Tethys Ocean was hypothesized by different authors. During the Late Triassic, the Tethys was open to the east on the Western Panthalassa but not to the west, suggesting that Triassic calcareous algae were able to efficiently colonize environments that are estimated to be more than 10’000 km apart. An adventitious transport of calcareous algae and/or their spores is proposed to explain this long-range algal dispersal

Downslope re-sedimentation from a short-living carbonate platform: Record from the Upper Triassic Hosselkus limestone (Northern California)

Despite their discontinuous occurrence and poor preservation, knowledge about Triassic carbonates from North America has increased considerably during recent years. Their characterization represents a uniqueway to better assess evolution and recovery of the biosphere after the major Permo-Triassic biological crisis in the Panthalassa Ocean. The Eastern Klamath terrane, located in Northern California, is a key terrane due to its geographic position. It is placed halfway between the terranes of the Canadian Cordillera and the Northern Mexico counterparts, both extensively studied and characterized in recent decades, leaving a gap in knowledge along the Pacific coast of the United States. A few kilometers north-east of Redding, Shasta County, California, Upper Triassic carbonates (i.e., the Hosselkus limestone) crop out as a narrow north–south belt about 20 km long, near the artificial reservoir of Lake Shasta. All the accessible localities in this region have been extensively sampled for microfacies and micropaleontological analysis, leading to new insights about the depositional condition and age of the Hosselkus limestone. A depositional model has been proposed for the first time, corresponding to a steep slope system subjected to platform progradation and collapse, recording shallow water facies and associated fauna in the form of calcareous breccia. Numerous conodont specimens have dated the whole succession as Upper Carnian. Identification of shallow water organisms, associated to a reliable stratigraphic interval, allowed comparison of the Hosselkus limestone with other Upper Triassic carbonates from the Panthalassan domain. Despite the faunal affinities, especially with buildups developed at middle-paleolatitudes, the Hosselkus limestone is among the oldest of the terrane-based carbonates in Eastern Panthalassa. Thanks to peculiar geodynamical and bathymetrical conditions, allowing carbonate deposition slightly earlier than in other terranes, the Hosselkus limestone probably acted like a pioneer reef and may have had a great influence in the further expansion of carbonate buildups in the eastern part of the Panthalassa Ocean

Entrevista a la Dra. Sandra Fucelli, flamante titular de la Sociedad Latinoamericana de Investigación en Abejas (SOLATINA)

Entrevista a la Dra. Sandra Fucelli, titular de la Sociedad Latinoamericana de Investigación en abejas (SOLATINA

Siliciclastic input controlling carbonate deposition on a low-angle ramp system: New insight from the Upper Triassic Luning Formation (Western-Central Nevada)

Although more than one century has passed since the first studies, knowledge about the Upper Triassic shallow-water carbonates from the Panthalassa Ocean remains lower than their Tethyan counterparts. Characterising these sedimentary rocks represents a unique way to deepen our understanding of the biosphere's evolution and recovery after the major Permian–Triassic biological crisis. The Triassic Luning Formation in Western–Central Nevada is a crucial sedimentary succession due to its considerable thickness and areal extent. Among the three members forming the Luning Formation, the present study has only described the upper one in detail due to the minor areal distribution of the Lower Member and the pure siliciclastic nature of the middle Member. All accessible localities in this region, 21 in total, have been extensively sampled for facies and micropalaeontological analyses, including conodonts and poorly preserved foraminifera, leading to new insights about the depositional conditions and exact age of the Luning Formation's Upper Member. A depositional model is proposed for the first time, corresponding to a low-angle ramp with homogeneous bathymetric and hydrodynamic conditions subjected to frequent siliciclastic input from the continent. The regular terrigenous influx causes a significant cyclicity in this portion of the formation, comprising heterogeneously thick limestone beds. The environment-diagnostic fauna is characterised by pioneer organisms that regenerate carbonate production after the main break related to the pure siliciclastic Middle Member's deposition. Numerous conodont specimens indicate that the entire Upper Member is middle Norian in age. Identifying the observed organisms, tied to a reliable stratigraphic interval, allows comparing the Luning Formation with other Upper Triassic carbonates from the Panthalassa Ocean, now cropping out at different latitudes on the eastern and western coasts of the Pacific Ocean. Despite some faunal affinities, especially with carbonate build-ups developed at middle-palaeolatitudes the Luning Formation differs from most other East Panthalassa carbonates because of its short palaeo-distance from the continent (i.e. the American craton), being deposited near the mainland coast instead of on an isolated volcanic arc

Influence of cultivar and concentration of selected phenolic constituents on the in vitro chemiopreventive potential of olive oil extracts

One of the main olive oil phenolic compounds, hydroxytyrosol (3,4-DHPEA), exerts in vitro chemopreventive activities (antiproliferative and pro-apoptotic) on tumor cells through the accumulation of H2O2 in the culture medium. However, the phenol composition of virgin olive oil is complex, and 3,4-DHPEA is present at low concentrations when compared to other secoiridoids. In this study, the in vitro chemopreventive activities of complex virgin olive oil phenolic extracts (VOO-PE, derived from the four Italian cultivars Nocellara del Belice, Coratina, Ogliarola, and Taggiasca) were compared to each other and related to the amount of the single phenolic constituents. A great chemopreventive potential among the different VOO-PE was found following this order: Ogliarola > Coratina > Nocellara > Taggiasca. The antiproliferative and pro-apoptotic activities of VOO-PE were positively correlated to the secoiridoid content and negatively correlated to the concentration of both phenyl alcohols and lignans. All extracts induced H2O2 accumulation in the culture medium, but this phenomenon was not responsible for their pro-apoptotic activity. When tested in a complex mixture, the olive oil phenols exerted a more potent chemopreventive effect compared to the isolated compounds, and this effect could be due either to a synergistic action of components or to any other unidentified extract constituen