Elias Kassabji’s Post

Nice and useful information about this molecule #diahopane in terms of source rock maturity and clay content #PetroleumGeochemistry #molecular_geochemistry #Geochemistry

Exploring the pore fluid origin and methane-derived authigenic carbonate properties in response to changes in the methane flux at the southern Ulleung Basin, South Korea - Frontiers in Marine Science: We investigated the geochemistry of gas, pore fluid, and methane-derived authigenic carbonate (MDAC) from four sites in the southern Ulleung Basin, South Korea. In contrast to Sites 16GH-P1 and 16GH-P5, Sites 16GH-P3, and 16GH-P4 are characterized by acoustic chimney structures associated with gas flux. The composition of gas and isotopic signatures of methane (CH4) (C1/C2+ > 300, δ13CCH4 < -60‰, δDCH4 ≤ -190‰) indicate microbial source CH4 at all sites. The upward migration of CH4 can affect the chemical and isotopic properties of pore fluid and gas-related byproducts (e.g., gas hydrate (GH) and MDAC) within the shallow sediments including the current sulfate-methane transition (SMT) (< 5 meters below seafloor). Although no GH was found, elevated Cl- concentrations (maximum = 609 mM) with low δD and δ18O values in Site 16GH-P4 pore fluids delineate the influence of massive GH formation in deeper sediment. In contrast, relatively constant Cl-, δD, and δ18O values in fluids from Sites 16GH-P1, 16GH-P3, and 16GH-P5 indicate a predominant origin from seawater. Pore fluids also exhibit higher concentrations of H4SiO4, B, Mg2+, and K+, along with increasing alkalinity compared to seawater. These observations suggest that marine silicate weathering alters fluid chemistry within the sediment, affecting element and carbon cycles. High alkalinity (up to 60 mM) and Mg2+/Ca2+ ratios (> 6) alongside decreasing Ca2+ and Sr2+ concentrations imply carbonate precipitation. MDACs with diverse morphologies, mainly composed of aragonite and magnesian calcite, and characterized by low carbon isotopic values (δ13CMDAC < -31.3‰), were found at Sites 16GH-P3 and 16GH-P4. Interestingly, δ13CMDAC values at Site 16GH-P3 are clearly differentiated above and below the current SMT. High δ13CMDAC values above the SMT (> -34.3‰) suggest the combined influence of seawater and CH4 migrating upward on MDAC precipitation, whereas low δ13CMDAC values below it (< -41.6‰) indicate a predominant impact of CH4 on MDAC formation. Additionally, the vertical variation of δ18OMDAC values at Site 16GH-P4, compared to the theoretical values, reflects an association with GH dissociation and formation. Our findings improve the understanding of fluid, gas, and MDAC geochemistry in continental margin cold seeps, providing insights into global carbon and element cycles. https://lnkd.in/e86v8VTx

https://bit.ly/3T0vKXy - Read the Article here Rheological Models for Behavior of Sesame (Sesamum indicum) oil University of Bucharest #Lubricant #Oil #Rheology #Sesame #chemistry #biochemistry #nanomaterial #analyticalchemistry #chemicalengineering #Phytochemicals #ChemicalSciences #ChemicalTechnology

Geochemical characterisation of the Turonian-Maastrichtian bituminous sands in Dahomey Basin, Southwestern Nigeria. The Turonian-Maastrichtian bituminous sands resource in the Dahomey (Benin) Basin, Southwestern Nigeria, is a potentially economically viable hydrocarbon reserve, which has recently attracted renewed attention. An integrated study involving the use of elemental composition, and geochemical analyses (gas chromatography flame ionisation detector (GC-FID), Fourier transform infrared (FTIR), and gas chromatography mass spectrometry (GC-MS)) were carried out to provide an improved understanding of this resource using geochemical signatures and evaluate the n-alkane distribution of bituminous sands to determine its aliphatic hydrocarbon distribution and the prevailing depositional conditions. Elemental composition shows the dominance of carbon (Av. 79.8%). The atomic ratios of H/C and O/C, respectively, range from 0.05 to 0.11, and 0.04 to 0.08. SiO2 is the dominant oxide, with concentrations ranging between 73.15 and 80.50 wt. %, while Zn is the dominant trace element. Twenty-three aliphatic hydrocarbons: C10, C13, C15, C17–C37, were identified on GC-FID, with distribution showing predominance of long-chain n-aliphatics, with a Carbon Preference Index (CPI) value range of 1.01 to 1.02. A bimodal n-alkane fingerprint envelope is visible on GC, with maxima between nC16–nC18 and nC27, indicating varied contributions from both terrigenous and non-terrigenous (possibly marine algae) organic matter. Despite the biodegradation of n-alkanes, GC-MS chromatograms (m/z 256) show evidence of bicyclic sesquiterpenes (BSs) in the bituminous sands investigated. Infrared (IR) spectra show the dominance of the hydroxyl functional group, while 2922.2cm-1 and 2855.1cm−1 are common in all the samples, revealing the presence of residual organics. This study revealed that the bituminous sands are highly waxy in nature and derived from higher plants of both marine and terrestrial source input with more influence from land-dwelling biogenic sources under oxic conditions.

I am really happy to share our newly published study entitled "Isotopic and kinetic constraints on methane origins in Icelandic hydrothermal fluids". In this study, led by Andri Stefánsson, we aim to unravel and quantify the sources of methane in high-temperature Icelandic hydrothermal fluids by employing a broad array of geochemical tools (gas chemistry, stable and radioactive isotopes, equilibrium and kinetic modeling). https://lnkd.in/ezT-CnHd

Coring of sediments and sampling of pore water are critical processes in marine geochemistry and microbiology. Together with scientists from Aarhus University and The University of Texas at Austin, we found that nearly all published pore water samples retrieved from subsurface sediments are contaminated by seawater to some degree. Our work demonstrates that data on sulfate concentrations in methanic sediments constitute a unique opportunity to quantify this contamination and thereby provide a better possibility to control it. Read more about it in our peer-reviewed publication: https://lnkd.in/e5ibP5iJ

At 𝗖𝗵𝗲𝗺𝗼𝘀𝘁𝗿𝗮𝘁 𝗔𝗣𝗔𝗖, partnered of with our world leading analytical laboratories of our sister company Chemostrat 𝗟𝘁𝗱, we have been driving forward the science of salt characterisation, correlation and distribution modelling as part of our advanced 𝗛𝘆𝗱𝗿𝗼𝗴𝗲𝗻 𝗣𝗿𝗼𝗴𝗿𝗮𝗺𝗺𝗲. Our most recent breakthroughs in sub-dividing complex salt bodies into discernible sub units, and correlating these across basins, stems from our innovative use of 𝗜𝗻𝗱𝘂𝗰𝘁𝗶𝘃𝗲𝗹𝘆 𝗖𝗼𝘂𝗽𝗹𝗲𝗱 𝗣𝗹𝗮𝘀𝗺𝗮 (𝗜𝗖𝗣) techniques, complemented by 𝗫-𝗥𝗮𝘆 𝗙𝗹𝘂𝗼𝗿𝗲𝘀𝗰𝗲𝗻𝗰𝗲 (𝗫𝗥𝗙). The power of 𝗜𝗖𝗣 in salt analysis: 𝗜𝗖𝗣-𝗢𝗘𝗦 (𝗢𝗽𝘁𝗶𝗰𝗮𝗹 𝗘𝗺𝗶𝘀𝘀𝗶𝗼𝗻 𝗦𝗽𝗲𝗰𝘁𝗿𝗼𝗺𝗲𝘁𝗿𝘆) provides high-precision data on major and minor elements, revealing subtle compositional variations within salt formations. 𝗜𝗖𝗣-𝗠𝗦 (𝗠𝗮𝘀𝘀 𝗦𝗽𝗲𝗰𝘁𝗿𝗼𝗺𝗲𝘁𝗿𝘆) offers unparalleled sensitivity for trace element quantification, allowing us to identify minute geochemical signatures that are often overlooked. The combination of 𝗜𝗖𝗣-𝗢𝗘𝗦 and 𝗜𝗖𝗣-𝗠𝗦, calibrated using our in-house proprietary methods and standards, delivers unrivaled precision and accuracy giving us a comprehensive elemental profile, from percentage levels down to parts per million concentrations. We also use 𝗫𝗥𝗙 in our first-stage programme as this offers rapid, non-destructive analysis for initial assessments. In this regard it is a cost-effective way to characterise some of the broader trends in chemistry, but it is our advanced 𝗜𝗖𝗣 process that truly unlocks the hidden complexities within salt bodies. This integrated approach enables us to develop detailed 𝗰𝗵𝗲𝗺𝗼𝘀𝘁𝗿𝗮𝘁𝗶𝗴𝗿𝗮𝗽𝗵𝗶𝗰 schemes, generate high-resolution, high-precision correlations within the salts and indeed the surrounding geology. The generation of such 𝗵𝗶𝗴𝗵-𝗾𝘂𝗮𝗹𝗶𝘁𝘆 𝗱𝗮𝘁𝗮, combined with novel processing and measurement profiles to ensure 𝘀𝗮𝗹𝘁 𝗰𝗵𝗮𝗿𝗮𝗰𝘁𝗲𝗿𝗶𝘀𝗮𝘁𝗶𝗼𝗻, is a major step forward in broad spectrum 𝗵𝘆𝗱𝗿𝗼𝗴𝗲𝗻 𝗲𝘅𝗽𝗹𝗼𝗿𝗮𝘁𝗶𝗼𝗻 and quantification workflows.  This approach has delivered to commercial delivery and project deadlines, a particularly successful deployment being in our recent work in the 𝗔𝗱𝗮𝘃𝗮𝗹𝗲 𝗕𝗮𝘀𝗶𝗻, where we've successfully applied the techniques to subdivide the complex salt formation in this basin. Our work is opening new possibilities for 𝗵𝘆𝗱𝗿𝗼𝗴𝗲𝗻 𝘀𝘁𝗼𝗿𝗮𝗴𝗲 site assessment and optimization, with further work on the key sales in Australia being a primary target for our ongoing work. As we continue to refine our methodologies, we're always eager to collaborate with others in this field. If you're interested in learning more about our approach or discussing potential applications, let's connect! #Geochemistry #HydrogenStorage #EnergyTransition #Chemostratigraphy

Join APATITE enthusiasts at the 4th European Mineralogical Conference 📢 🗓 Date: 18-23 August 2024, 📍 Location: Trinity College Dublin "Apatite – an accessory mineral with a big footprint in geochemical, environmental, and biological processes"   Due to its robust crystal structure allowing for many cationic and anionic substitutions, the apatite supergroup is one of the largest mineral families known. One of its most prominent members, fluorapatite, is a major sink for P, F, and REE in the Earth’s crust and the upper mantle since it occurs as an accessory mineral in almost all rock types. As a host for many isotopes commonly used in radiometric techniques, it plays a significant role in petrochronology. Although normally an accessory mineral, apatite can also be a rock-forming mineral in sedimentary phosphorites and igneous ore deposits of economic importance such as iron oxide-apatite deposits and carbonatites. While it is also the main component of teeth, bones, and certain invertebrate exoskeletons, synthetic apatite and its derivatives have applications in a variety of fields including the pharmaceutical industry and tissue engineering. Moreover, apatite is the foundation of the global phosphorous cycle as well as an essential source for fertilizer and an important agent in environmental remediation. Here we invite all contributions devoted to minerals of the apatite supergroup, both from nature and experiment, including applications in geological and biological systems as well as in agriculture and industry.   Conveners: - Dave Chew (Trinity College Dublin, Ireland) - Daniel Harlov (GFZ German Research Centre for Geosciences) - Alicja Wudarska (Institute of Geological Sciences of the Polish Academy of Sciences and GFZ German Research Centre for Geosciences) - Bartosz Puzio (AGH University of Krakow, Poland) ⚠ The abstract submission deadline (22nd March 2024) is fast approaching! Conference website 👉🏻 https://lnkd.in/d-wa8XRf

It's hot off the press!! We are delighted to share our newly published article titled "Isotopic and Geochemical Modeling Approach to Evaluate Abiotic Nitrite Reduction by Ferrous Iron", available in open access: https://lnkd.in/dhwEMbs3 This research, part of Alex Tiewin Abu phD thesis together with other MAiMA researchers, tested the ability of Fe(II) minerals such as siderite (also in the presence of dissolved Fe(II)) to induce nitrite reduction. A geochemical model coupling nitrite- reduction-Fe(II) oxidation, kinetic isotope fractionation, aqueous speciation in equilibrium and calcite precipitation and dissolution has been implemented to reproduce the experimental results. This geochemical model serves as a foundation for future field applications in using Fe(II) minerals for groundwater nitrate treatment.   #nitrate #nitrite #water #isotopes #contamination