The Earth's sole active carbonatite volcano, Oldoinyo Lengai (Tanzania), is presently erupting unique natrocarbonatite lavas that are characterized by Na- and K-bearing magmatic carbonates of nyerereite [Na2Ca(CO3)2] and gregoryite [(Na2,K2,Ca)CO3]. Contrarily, the vast majority of older, plutonic carbonatite occurrences worldwide are dominated by Ca-(calcite) or Mg-(dolomite)-rich magmatic carbonates. Consequently, this leads to the conundrum as to the composition of primary, mantle-derived carbonatite liquids. Here we report a detailed chemical investigation of melt inclusions associated with intrusive (plutonic) calcite-rich carbonatites from the ~120 Ma carbonatite complex of Oka (Canada). Melt inclusions are hosted by magnetite (Fe3O4), which crystallizes through a significant period of carbonatite melt solidification. Our results indicate mineral assemblages within the melt inclusions that are consistent with those documented in natrocarbonatite lavas. We propose therefore that derivation of alkali-enriched parental carbonatite melts has been more prevalent than that preserved in the geological record.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/ncomms3687 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Damage due to ice crystallization.
Sci Rep
January 2025
Van der Waals-Zeeman institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
The freezing of water is one of the major causes of mechanical damage in materials during wintertime; surprisingly this happens even in situations where water only partially saturates the material so that the ice has room to grow. Here we perform freezing experiments in cylindrical glass vials of various sizes and wettability properties, using a dye that exclusively colors the liquid phase; this allows precise observation of the freezing front. The visualization reveals that damage occurs in partially water-saturated media when a closed liquid inclusion forms within the ice due to the freezing of the air/water meniscus.
View Article and Find Full Text PDFTuning of Water Vapor Permeability in 2D Nanocarbon-Based Polypropylene Composite Membranes.
Nanomaterials (Basel)
December 2024
Foundation for Research and Technology-Hellas (FORTH), Institute of Chemical Engineering Sciences (ICE-HT), Stadiou Str., GR-265 04 Rio-Patras, Greece.
This work focuses on the incorporation of 2D carbon nanomaterials, such as graphene oxide (GO), reduced graphene oxide (rGO) and graphene nanoplatelets (GNPs), into polypropylene (PP) via melt mixing. The addition of these 2D carbon nanostructured networks offers a novel approach to enhancing/controlling the water vapor permeable capabilities of PP composite membranes, widely used in industrial applications, such as technical (building roof membranes) or medical (surgical gowns) textiles. The study investigates how the dispersion and concentration of these graphene nanomaterials within the PP matrix influence the microstructure and water vapor permeability (WVP) performance.
View Article and Find Full Text PDFRelease and Disintegration Properties of Poly(lactic Acid) Films with Allyl Isothiocyanate-β-Cyclodextrin Inclusion Complexes for Active Food Packaging.
Molecules
December 2024
Department of Analytical Chemistry, Nutrition & Food Sciences, University of Alicante, 03690 Alicante, Spain.
This study aimed to enhance the properties and compostability of active poly(lactic acid) (PLA) films by incorporating β-cyclodextrin (β-CD) inclusion complexes with allyl isothiocyanate (AITC). Films were prepared using melt extrusion and characterized based on their structural, chemical, morphological, thermal, and barrier properties. These inclusion complexes improved the thermal stability and moisture absorption of films, enhancing disintegration under composting conditions.
View Article and Find Full Text PDFThe Effect of Ice-Binding Protein from sp. AY30 (LeIBP) on the Physicochemical Quality and Microstructure of Largemouth Bass During Freeze-Thaw Cycles.
Foods
December 2024
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
This study investigated the effect of various concentrations (0.01%, 0.05%, 0.
View Article and Find Full Text PDFProbing the impact of commercial cryoprotectants and freezing technique on the motility of human spermatozoa cryopreserved onto extremely water-repellent soot-coated surfaces.
Cryobiology
January 2025
Specialized Surgical Hospital "Doctor Malinov", 46, Gotse Delchev blvd., 1860, Sofia, Bulgaria.
The cryopreservation of human spermatozoa is an integral part of cryobiology, aiming to support the in-vitro fertilization. The latter relies on the availability of as much as possible reproductively active spermatozoa, whose number after thawing decreases due to the accompanied freezing injury and the cytotoxicity of cryoprotectants. An innovative option to circumvent these obstacles is to make the freezing interface non-wettable, by coating it with rapeseed oil soot possessing intrinsic cryoprotective properties, delaying the ice formation and possibly providing identical rates of intracellular dehydration and extracellular crystallization.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!