GeoSciences

Mineralogia, vol. 56, no. 1, p. 44-51

Stepien E., Manecki M. & Bajda T. (2025).- Mimetite precipitation on Pb-clinoptilolite: an effective approach for arsenate removal from water.- This short communication proposes a novel approach to arsenate remediation using in situ precipitation of mimetite [Pb5(AsO4)3Cl], a sparingly soluble mineral phase with an apatite structure. The Pb2+ source was provided by a lead-modified zeolite (clinoptilolite) loaded with approximately 70 g Pb/kg. It was reacted with arsenate (50 mg As/L) and chloride (20 mg Cl/L) at initial pH values of 2 and 7. Mimetite crystallized on and in the vicinity of zeolite due to the reaction of Pb(II) desorbed from zeolite with arsenate and chloride ions present in aqueous solution. Mimetite formed rapidly resulting in efficient arsenate sequestration. At pH 7, arsenate removal reached 99.88% after 24 hr, with minimal lead release (<0.02 mg/L). These results demonstrate that lead-modified clinoptilolite is a promising material for a coupled sorption–precipitation mechanism which provides an effective strategy for arsenic immobilization in contaminated aqueous systems.
https://doi.org/10.2478/mipo-2025-0006
Wed, 23 Jul 2025 10:00:00 GMT

Geologia Croatica, vol. 78, no. 02, p. 103-113

Ioan I. Bucur, Emanoil Săsăran & George Pleş (2025).- Schlagintweitella inopinata, a new genus and species of Dasycladales (green algae) from the Upper Jurassic limestones of Romania.- Within the Upper Jurassic deposits of the Cioclovina-Băniţa area (Southern Carpathians), an outcrop was identified that most likely corresponds to a cavern fill. In several clasts of this fill, including black-pebbles, we found a dasycladalean alga whose morphological features differentiate it from all other Jurassic-Cretaceous dasycladalean algae with two orders of laterals. This alga is described in the present work as a new species of a new genus: Schlagintweitella inopinata nov. gen., nov. sp.
https://doi.org/10.4154/gc.2025.10
Mon, 30 Jun 2025 17:43:46 GMT

Palaeontologia Electronica, 27(2):a26

Tom T.P. van der Linden, Michael P. Taylor, Amy Campbell, Brian D. Curtice, René Dederichs, Lucas N. Lerzo, John A. Whitlock, D. Cary Woodruff & Emanuel Tschopp (2025).- Introduction to Diplodocoidea.- Diplodocoidea is one of the most iconic clades of the giant sauropod dinosaurs, known for their elongated necks and tails, and distinctive skull morphology. This group, existing from the Middle Jurassic to the early Late Cretaceous, encompasses three main families: Rebbachisauridae, Dicraeosauridae, and Diplodocidae. These sauropods were globally distributed, demonstrating significant diversity in body plans, feeding strategies, and ecological niches. Diplodocoid paleontology has been marked by extensive studies focusing on skeletal morphology, biomechanics, histology, and evolutionary relationships. Significant research has also explored their ontogeny and niche partitioning, suggesting that diplodocoids had specialized adaptations for low- to mid-level browsing. This contribution is the introduction to a special volume that aims to synthesize current research on Diplodocoidea, offering insights into their evolutionary success, with subsequent contributions addressing their phylogenetic relationships, ontogeny, and morphological variation.
https://doi.org/10.26879/1518
Sun, 29 Jun 2025 17:43:46 GMT

Volumina Jurassica, vol. XXIII, p. 43-64

Hudson A.J.L., Hesselbo S.P., Hinnov L.A., Littler K., Page K.N., Riding J.B., Ruhl M. & Ullmann C.V. (2025).- Astrochronology of the Sinemurian Stage from the Llanbedr (Mochras Farm) core, NW Wales: Implications for the Early Jurassic timescale.- Early Jurassic palaeoenvironments were perturbed during episodes of major global climate and biogeochemical change at the Triassic–Jurassic boundary and Early Toarcian Oceanic Anoxic Event (T-OAE). Other poorly understood palaeoclimate fluctuations and carbon-cycle perturbations occurred between these episodes, including the mid-Sinemurian Liasidium Event and the Sinemurian–Pliensbachian Boundary Event. Understanding of the causes and significance of these phenomena is limited by uncertainties in the geological timescale, particularly for the Sinemurian Stage. In this paper we present new multiproxy geochemical data through the Sinemurian and earliest Pliensbachian stages from the Llanbedr (Mochras Farm) borehole (NW Wales). The Mochras record is apparently stratigraphically complete except in the Upper Sinemurian which is affected by a normal fault that removes the lower part of the Oxynotum Zone. A floating astrochronology is developed for the Sinemurian Stage based on identification of the 405-kyr orbital eccentricity “metronome� in weight percent calcium and stable organic carbon isotopes (d13Corg) from Mochras, together with data from the Robin Hood’s Bay base-Pliensbachian GSSP section in Yorkshire, UK. The results indicate a minimum duration for the Sinemurian Stage of 7.3 Myr (7.1 Myr from Mochras and an additional 0.2 Myr from Robin Hood’s Bay for the lower Oxynotum Zone). This interpretation of a long Sinemurian requires a short duration (~2 Myr) for the Hettangian stage.
https://vjs.pgi.gov.pl/article/view/34506
Thu, 27 Jun 2025 17:00:00 GMT