Mineral Element Composition Research Articles

Determination of Compressive Strength and Combustibility Potential of Agricultural Waste Briquette

This study evaluates the development of a substitute and alternative solid fuel in the form of briquette from agricultural wastes (rice husk, sawdust and cotton stalk charcoal). Four sets of briquette with different grades were produced using a discontinuous briquette production technology, where a single briquette is produced at a time in a closed mould. Some physical properties such as; Length of briquettes (170 mm), diameter of briquettes (50 mm), mass of briquettes (140-160 g), volume of briquettes (133.5 cm3), density of briquettes (1.05-1.20 gm3), texture of briquettes (rough), and colour of briquettes (brown, light brown and mud black), were investigated using physical methods of evaluation. The result of the proximate analysis (moisture 10.5-10.8%, ash 30.3-33.8%, volatile matter 20.5-25.9% and fixed carbon contents 45.2-52.6%. The burning potential tests carried out on the formed briquettes compared to that of firewood showed that firewood boils 5 litres of water in 60 minutes, while Rice husk, Sawdust, Cotton stalk charcoal blended with rice husk, and Sawdust briquettes boils the same volume of water in 35, 30, 20 and 25, minutes respectively. Compressive strength of the briquettes was determined as 155.9, 155.9, 158.1 and 158.1 KN/m2 for rice husk, sawdust, cotton stalk charcoal blended with rice husk and sawdust briquettes respectively. Energy dispersed x-ray fluorescence spectrometer (ED-XRF) analyses revealed the existence of minor and major elemental percentage compositions (Cl, Br, P, K, Ca, Ba, Cu, Zn, Fe, Mn and Si, Ti, V, Cr, Ni, Sr, Rb). Liebig’s and Kjeldahl’s methods of laboratory analyses confirmed the presence of organic elements (C, H, O, N and S) that contributes to the heating value, increase in ignitability, smooth combustion. It can, therefore, be concluded that briquettes produced in this research work provide a better alternative to firewood and charcoal energies, they are eco-friendly, having high heat intensity with smooth burning and are easy to handle, store and transport, they are very cheap, affordable to both rural and semi-urban dwellers.

Effects of Malting on Nutritional Characteristics of Pigeon Pea (Cajanus cajan)

Background/Objective: Malting is a process that is not expensive and is technologically effective in improving the nutritional quality of food. The objective of this study was to determine the effect of malting on the nutritional characteristics of pigeon pea (Cajanus cajan).
 Materials and Methods: The pigeon pea seeds were sorted and washed. The seeds were then steeped in water at 29°C for 24 hours. Changing of water at 6 hours interval was observed during steeping. The resultant steeped seeds were spread on jute bag and were covered with white cotton cloth to germinate for 72 hours. The sprouted seeds were oven dried at a temperature of 50°C for 1 hour and thereafter, the plumules were separated from the seed and the malted seeds were dried and milled into flour. Both the raw and malted samples were subjected to laboratory analysis for proximate, mineral element composition, anti-nutrients and functional properties. The results were determined in triplicate and subjected to statistical analysis using SPSS version 20.
 Results: The result of the proximate analysis showed that the samples were generally low in moisture which are 12.81±0.07 and 15.10±0.81%, protein content are 19.01±0.08 and 22.10±0.16%, Ash content are 2.27±0.23 and 3.18±0.47%, Fat content are 1.02±0.32 and 1.68±0.81%, fibre content are 0.45±0.52 and 1.23±0.63%, carbohydrate are 57.37±0.28 and 63.78±0.01% and energy were 300.32 and 326.20 Kcal/100 g for raw and malted sample respectively. The result of minerals are iron 0.13±0.12 and 1.03±0.08 mg/100 g, magnesium 50.30±0.01 and 68.24±0.45 mg/100 g, zinc 0.27±0.21 an 0.88±0.32 mg/100 g, phosphorus 13.10±0.57 and 18.30±0.32 mg/100 g, potassium 2.10±0.62 and 4.50±0.08 mg/100 g, sodium 6.10±0.31 and 9.33±0.07 mg/100 g and calcium 7.28±0.41 and 10.11±0.22 mg/100 g for raw and malted sample respectively. The anti-nutrients determined are phytate 19.86±0.03 and 7.22±0.78 mg/100 g, oxalate 1.78±0.03 and 0.02±0.42 mg/100 g, trypsin inhibitor 40.53±0.42 and 10.30 m±0.07 g/100 g, tannins 28.80±0.50 and 9.12±0.18 mg/100 g and hydrogen cyanide 1.63±0.68 and 0.68±0.04 mg/100 g, for the raw and malted pigeon pea respectively. The functional properties are Bulk density 0.62±0.81 and 0.98±0.01 g/cm3, water absorption capacity 227.05±0.24 and 261.220.38%, oil absorption capacity 162.72±0.11 and 170.54%±0.42, foaming capacity 18.80±0.28 and 37.73±0.21% and swelling capacity 4.08±0.13 and 6.24±0.31%.
 Conclusion: It was observed that highly nutritious flour can be produced from pigeon pea using malting.

MINERAL CHEMISTRY AND GEOCHEMISTRY OF HYPERSTHENE-BEARING DIORITE FROM ERUSU AKOKO, SOUTHWESTERN NIGERIA

Samples of mafic intrusive rock were analyzed for their mineralogical and chemical properties. The textural relationship was studied using the petrographic microscope, elemental composition of minerals was determined using the Electron Microprobe and the whole rock chemical analysis was done using the XRF and ICP-MS. The following minerals were observed in order of abundance; pyroxene, amphibole, plagioclase, biotite, opaque minerals, quartz and chlorite, with apatite and zircon occurring as accessory mineral. Two types of pyroxenes were observed; orthopyroxene (hypersthene) and clinopyroxene. Texturally, amphiboles have inclusions of plagioclase and pyroxene. The plagioclase has undergone sericitization. The chemical composition of the pyroxene is En51.95Fs44.53Wo3.52, biotite has Fe/(Fe+Mg):0.42, Mg/(Fe+Mg):0.59, and plagioclase is Ab63.5An34.55Or1.95. Whole rock chemistry shows a chemical composition; SiO2: 45.15 %, Al2O3: 14.04 %, Fe2O3: 16.01 %, MgO: 5.65 %, CaO: 7.58 % and TiO2: 3.59 %. There is an enrichment of LREE and a depletion of HREE. Based on the minerals, mineral chemistry and the geochemistry of the studied rock, the rock is mafic and hydrous minerals formed by hydration recrystallization of pyroxene. The rock has extensively retrogressed but has not been affected by any form of deformation.

Mineral Element Composition in Grain of Awned and Awnletted Wheat (Triticum aestivum L.) Cultivars: Tissue-Specific Iron Speciation and Phytate and Non-Phytate Ligand Ratio.

In wheat (Triticum aestivum L.), the awns—the bristle-like structures extending from lemmas—are photosynthetically active. Compared to awned cultivars, awnletted cultivars produce more grains per unit area and per spike, resulting in significant reduction in grain size, but their mineral element composition remains unstudied. Nine awned and 11 awnletted cultivars were grown simultaneously in the field. With no difference in 1000-grain weight, a larger calcium and manganese—but smaller iron (Fe) concentrations—were found in whole grain of awned than in awnletted cultivars. Micro X-ray absorption near edge structure analysis of different tissues of frozen-hydrated grain cross-sections revealed that differences in total Fe concentration were not accompanied by differences in Fe speciation (64% of Fe existed as ferric and 36% as ferrous species) or Fe ligands (53% were phytate and 47% were non-phytate ligands). In contrast, there was a distinct tissue-specificity with pericarp containing the largest proportion (86%) of ferric species and nucellar projection (49%) the smallest. Phytate ligand was predominant in aleurone, scutellum and embryo (72%, 70%, and 56%, respectively), while nucellar projection and pericarp contained only non-phytate ligands. Assuming Fe bioavailability depends on Fe ligands, we conclude that Fe bioavailability from wheat grain is tissue specific.

Mineral profile of weight loss related foods marketed in Spain

Low calorie foods are products designed to replace complete meals or to control snacking in many hypocaloric diets. These products provide many nutrients to the human diet, but little is known about their mineral elements composition. Here we study the mineral profile of weight loss related products, including the analysis of 22 elements (As, Ba, Be, Bi, Cd, Co, Cr, Cu, K, Mn, Mo, Na, Ni, P, Pb, Th, Tl, Sb, U, V, Y and Zn) in 73 commercial products marketed in Spain. In general a portion of these products provide up to 20–30% of the daily dietary reference intake of essential trace minerals like Cr or Mo. On the contrary, some of these foods have large concentrations of toxic minerals like As, Cd or Pb. In fact, the intake of those products with higher concentrations of toxic elements during a weight loss program could pose a risk to human health.

Evolution of Mineral Composition during Eclogite Metamorphism in the Belomorian Mobile Belt: Data from Vichennaya Luda Island

The detailed mineralogical-geochemical study of eclogites and their retrograde products (amphibolites in a rim of eclogite boudin) from Vichennaya Luda Island (Keret Archipelago, White Sea) revealed systematic variations in major-, trace and rare-earth element composition of rock-forming minerals, which should be taken into account in geochronological and thermobarometric studies. Garnets from garnet–amphibole interlayers in the eclogites demonstrate a prograde zoning. In addition, garnet rims differ from their cores in a “hump-like” REE pattern owing to the elevated Sm, Eu, Gd and Dy contents and a negative slope of HREE pattern, as well as in an increase of Sm/Nd and a decrease of Lu/Hf ratio. It has been established that the eclogites contain clinopyroxene with depleted (to chondritic level) REE content, a positive Eu anomaly, and lowered Ti, V, Cr, Y, Zr, and Hf contents. Based on these geochemical features, the Cpx can be ascribed to relict that have preserved during peak eclogite metamorphism. Amphiboles in amphibolite rim of boudin differ sharply from amphiboles in eclogite in the lowered contents of LREE and some HREE. In addition to almost a two-fold decrease of Ti content in the eclogite–amphibolite sequence, amphiboles demonstrate a significant decrease of V, Sr, Y, Nb, and Hf contents. All biotites have sinusoidal REE pattern, which is typical of minerals formed through fluid-induced disequilibrium processes. Biotite from eclogites has higher Ti content and elevated contents of REE, Nb, V, Cr, Ba, and Hf as compared to biotites from the amphibolization rim. The eclogites and amphibolites developed after them are similar in major, trace, and rare-earth element composition.

In Vitro Antioxidant and Antidiabetic Potentials of Syzygium caryophyllatum L. Alston.

Syzygium caryophyllatum L. Alston (Family: Myrtaceae, Sinhala: Heendan) is a red-listed plant that has been used in traditional medicine in Sri Lanka for the treatment of diabetes, but it is yet to be exploited for its potential uses as a functional food or a source of supplements. The present study focused on the evaluation of antidiabetic property of S. caryophyllatum fruits and leaves assessing antioxidant, antiglycation, and antiamylase activities and functional mineral element composition. The crude extracts (CR) of leaves and fruits were fractionated into hexane (Hex) ethyl acetate (EA) and aqueous (AQ) and evaluated for bioactivities along with the crude extracts. The isolated fraction (C3) of Hex fraction of fruit showed significantly high (p < 0.05) antiamylase activity with IC50 value 2.27 ± 1.81 μg/mL where the Hex fraction of fruits exhibited the IC50 value as 47.20 ± 0.3 μg/mL which was higher than acarbose (IC50: 87.96 ± 1.43 μg/mL). The EA fraction of leaves showed highest values for DPPH radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity. Significantly high (p < 0.05) ABTS radical scavenging activity and iron chelating activity were observed in Hex fraction of fruit. The composition of volatiles in leaf oil was studied with GC-MS, and 58 compounds were identified. Inductively coupled plasma-mass spectrometry data revealed the presence of biologically significant trace elements such as Fe, Zn, Mg, Cu, Se, and Sr in leaves and fruits. It is concluded that the Hex fraction of S. caryophyllatum fruits will be a good source for the formulation of supplements for diabetic management with further evaluation of potency and efficacy.

THE CONTENT OF MINERAL SUBSTANCES AND VITAMINS IN THE GRAPE VARIETIES OF MUSCAT PEITEL, SALAM, YAI PINK RAISINS

The qualitative composition and quantitative content of mineral elements and vitamins in the grapes of local varieties of Muscat Peitel, Salam, Yai pink raisins, growing in southern Dagestan, are studied. The elemental composition is determined by the methods of flame and atomic absorption photometry; ascorbic acid - titrimetry; rutin, nicotinic acid and carotene - colorimetry. A certain correlation of minerals and vitamins has been found, and it is crucial at selection of grapes, aimed at high nutritional value. The obtained results can be useful at the correct selection and placement of the varieties with the optimal combination of micronutrients to provide the Republic with table grapes of good quality.

Comparison of the chemistry and mineralogy of ilmenite concentrates sourced from fluvial (Brahmaputra River) and beach placer (Cox’s Bazar) deposits, Bangladesh

Bangladesh has known concentrations of heavy mineral (HM) sand resources in shoreline placer deposits along the southern and eastern coastlines and also within river sand bar placer deposits associated with the extensive river systems throughout the country. The high-grade Cox’s Bazar beach placer deposits are in populated and environmentally sensitive areas making the future of mineral sands exploitation uncertain. In comparison, the Brahmaputra fluvial deposits are less rich in total HMs but constitute a potential major resource.The recovery of Ti-rich ilmenite from beach placer deposits is widespread but rare from fluvial deposits however many river systems in Bangladesh are annually dredged to maintain open waterways offering a new source of heavy minerals. Exploitation will depend on the quality of the ilmenite compared to existing commercially traded material. In this study, ilmenite concentrates derived from fluvial deposits (Brahmaputra River) and beach placer deposits (Cox’s Bazar) were compared using XRF, XRD and EPMA techniques.The level of impurities associated with the Brahmaputra River ilmenite was higher than in the equivalent Cox’s Bazar fractions suggesting possible issues with liberation or the properties of the associated gangue minerals reacted differently to the separation conditions, or both. Ilmenite from both regions exhibited texturally alike grain types and chemically similar compositions with detrital ilmenite from Cox’s Bazar characterised by TiO2 contents ranging from 49–53 wt-% (average 51 wt-%) while the range for the Brahmaputra River was 44–53 wt-% (average 49 wt-%). The slightly higher and much narrower range in TiO2 for the Cox’s Bazar material was consistent with this material having been subject to more chemical weathering resulting from a longer transit time and reworking through wave action. Based on the major and minor element compositions of ilmenites from both sources, the most likely route for processing the ilmenite-rich component would be via the sulphate route to pigment.

Determination of the geographical origin of maize (Zea mays L.) using mineral element fingerprints.

Maize (Zea mays L.) is a staple cereal crop and feed crop throughout the world. In this article, a mineral element fingerprinting technique was applied to single out suitable element indicators to determine the geographical origin of maize. A total of 90 fresh maize samples were collected in 2107 from Jilin, Gansu, and Shandong provinces in China. The contents of 25 mineral elements in all maize samples were measured by inductively coupled plasma mass spectrometry (ICP-MS). The composition of mineral elements was analyzed by multivariate statistical analysis, including one-way analysis of variance (one-way ANOVA), principal component analysis (PCA), k-nearest neighbor (KNN) analysis, and stepwise linear discriminant analysis (SLDA). As compared by one-way ANOVA, the contents of 19 mineral elements in maize samples were significantly different among three provinces. Principal component analysis based on these 19 elements could obtain preliminary visual classification groups of maize samples. K-nearest neighbor analysis produced a total correct classification rate of 83.9% on the training set, and 82.2% on the prediction set. The SLDA model, based on eight indicative elements (Na, Cr, Rb, Sr, Mo, Cs, Ba, and Pb) obtained a total correct classification rate of 92.2% with cross-validation. The mineral element fingerprinting technique combined with multivariate statistical analysis could be a helpful method to identify the geographical origin of maize. © 2019 Society of Chemical Industry.

Ages and glass compositions for paired large-volume eruptions from the Acigöl volcanic complex, Cappadocia (Turkey)

Acigol volcanic complex is a bimodal volcanic field located at the western margin of the Neogene–Quaternary Cappadocian volcanic province in Central Anatolia (Turkey). Its most voluminous eruptions are preserved as a pair of widespread tuffs known as Lower Acigol Tuff (LAT) and Upper Acigol Tuff (UAT). Both are nearly aphyric high-silica rhyolites that are compositionally identical; they can be distinguished, however, by the presence of obsidian lithics in UAT and the absence thereof in LAT. Here, we report the discovery of medial deposits of these tuffs at ~ 60–65 km distance from their source, and re-estimate the volume for LAT in the range of 21.4–26.7 km3 (similar constraints are lacking for UAT, but a subequal volume is assumed). Development of paleosol between LAT and UAT provides evidence for a hiatus between both events which is further supported by radiometric dating using combined U–Th and (U–Th)/He zircon geochronology. The revised age for LAT based on sequence modeling of U–Th zircon crystallization and (U–Th)/He zircon eruption ages is 190 ± 11 ka, whereas new and published (U–Th)/He zircon ages indicate eruption of UAT at 164 ± 4 ka (uncertainties generally stated at 1σ). The compositional similarity between both eruptions previously known from whole-rock analyses also extends to glass major, minor, and trace element compositions. Moreover, U–Th zircon crystallization ages are also indistinguishable between LAT and UAT in proximal and medial locations. U–Pb zircon ages for crystals in secular equilibrium indicate a provenance from Cretaceous granitic basement and Miocene volcanic overburden typical for Cappadocia, and such xenocrysts appear to be slightly more common in LAT compared to UAT. The compositional similarity between LAT and UAT along with the apparent recycling of zircon from the non-erupted LAT magma during the UAT event indicates sequential tapping of rhyolite melt from a magma system that maintained thermal and compositional uniformity over a protracted time interval. This can be explained by rhyolite melt extraction from a thermally buffered crystal mush that remained viable to produce voluminous high-silica eruptions for few 10s of ka. The subsequent migration of eruptive activity in the Acigol volcanic complex from east to west also led to a change in magma chemistry and triggered a new pulse of zircon crystallization, indicating abandonment of the previous magmatic focus, and a shift of magma input to a new location. The identification of sizable medial deposits of LAT and UAT implies that both tephra units are potentially useful marker horizons for marine isotope stage (MIS) 6 sedimentary sequences in and around Anatolia. The recent discovery of UAT in a Black Sea sediment core supports this view.

Trace and rare earth element compositions of Silurian conodonts from the Vesiku Bone Bed: Histological and palaeoenvironmental implications

In-situ minor, trace and rare earth element (REE) compositions have been measured in conodonts from the lower Silurian Vesiku Bone Bed (Estonia), with the aim to visualize and to quantify conodont apatite elemental geochemistry, to evaluate compositional differences between conodont histologies, and to evaluate the use of conodont chemistry as a palaeobiological or palaeoenvironmental proxy. Tissue-selective analyses of minor, trace and rare earth element compositions of albid, hyaline, and basal tissues demonstrated significant chemical offsets among these histologies. The albid tissue had the lowest REE and trace element concentrations, suggesting crystallinity-determined better resilience to diagenetic alteration as documented in previous studies. Conversely, the basal tissue had highest concentrations of REEs and many trace elements, except for Sr that showed an opposite trend. The higher concentrations in albid and hyaline tissues supports the in-vivo Sr incorporation by conodont crown. Nonetheless, the obtained SN-normalized REE patterns were uniform through all the analyzed conodont taxa and different tissues, implying common diagenetic history. Absence of a Ce anomaly, and defined negative Eu anomaly indicate reducing conditions during early burial. These results validate current interpretations of the palaeoenvironmental conditions during the deposition of Vesiku Bone Bed and bolsters the use of REEs in Palaeozoic marine vertebrates as an important palaeoenvironmental proxy.

Geochemical and isotopic constraints on the evolution of magma plumbing system at Damavand Volcano, N Iran

Damavand is a Quaternary stratovolcano in N Iran, associated with small volumes of under-saturated to weakly-saturated mafic lavas (Tephrite-Basanite-Alkali olivine basalt), and large volumes of saturated lavas (trachyandesite-trachyte (TT)) together with minor pyroclastic rocks. TT rocks are characterized by LILE and HFSE enrichments, whereas the mafic rocks have higher REE and other incompatible elements (except Rb, Th) than TT suite rocks, contradicting the assumed derivation of TT magmas from mafic magmas by simple fractional crystallization processes. The similar whole-rock isotope ratios of mafic rocks, TT suites and their enclaves do suggest a common origin. Magmatic enclaves in TT suites show decoupled major and some trace elements from their host while they have similar geochemistry to the mafic lavas. Trace element modeling including assimilation-fractional crystallization (AFC) and energy-constrained recharge-assimilation fractional crystallization (EC-RAFC) suggest that the Damavand TT rocks were formed by multi-stage fractionation of mafic magma with minor effects of open system processes. Differentiation started at high pressures (6–8 kbar, initial temperature of magma (Tm) = 1180 °C) involving anhydrous minerals (mainly clinopyroxene-orthopyroxene), accompanied by recharge and wall-rock assimilation at equilibration temperature (Teq) of 1050 °C as the magma reached the threshold for extraction from crystal mush (Mm = 0.49) (stage-1). These processes resulted in the enrichment of the residual liquid in incompatible elements. The fractionation of oligoclase-andesine, anorthoclase, phlogopite and apatite from intermediate enriched melts occurred at shallow crustal levels (0.5–3 kbar, Tm = 1050 and Teq = 830 °C): here, FC processes and further recharge and assimilation of crustal materials reduced LILE and REE concentration in the residual liquid (stage-2). The role of enriched melts is supported by unusual trace element composition of key minerals, for instance, feldspars have variable concentrations of Ba (132–5495 ppm), Sr (1471-14413 ppm) and unusual Rb, La and Ce contents. Based upon melt extraction modeling, physical removal of residual melts at stage-2 could produce cumulate residues with trace element compositions comparable to enclaves in TT suites (stage-3). Disruption of crystal mush due to recharge, followed by mixing of enclave material with evolved trachytic melts caused buffering of magma at trachyandesitic composition (stage-4). The results affirm the advantages of using a range of compositional and textural records in modeling of petrogenetic processes in all magmatic plumbing systems.

Evaluation of Changes Biological Activity of Onosma Sericeum Willd (Boraginaceae) Based on Collection Time and Extraction Solvent, and Determination of Its Mineral and Trace Element Composition

In this study total phenol, flavonoid, and free radical scavenging activity of Onosma Sericeum Willd (Boraginaceae), grown in Turkey and used for traditional wound healing were determined using spectrophotometric methods. Its cytotoxic effect on breast (MCF-7) cancer cells was investigated. Furthermore, mineral and trace element composition of the plant roots, collected in different times, was determined using ınductively coupled plasma mass spectroscopy (ICP-MS). Onosma sericeum Willd, collected in Besni, Adıyaman region in May, June and July, and dried properly, were extracted by using different solvents in the study. Total phenol content of the extracts was calculated using the Folin-Ciocalteu method in gallic acid equivalent as 58, 42±0, 13-93, 34±0, 68 mg (GAE)/g. The flavonoid content was calculated as 21.79±1, 3-60, 33±0, 36 mg (KUE)/g in quercetin equivalent by using the aluminum chloride method. Free radical scavenging activity was measured through a spectrophotometer according to 2,2-diphenyl-1- picrylhydrazyl (DPPH) assay. DPPH radical scavenging activity rates were found to be in the range of 60.27±0.06-78.60±0.21% in the form of % inhibition. It was observed that extracts prepared by using ethanol produced cytotoxic effect on the MCF-7 cancer cells depending on the dosage. It was determined that the rates of phenol, flavonoid, free radical scavenging activity and cytotoxic effect differed based on the solvent used for extraction and the time of plant collection. Moreover, trace element and mineral composition of the plant samples collected in different times were determined.

Pyroxenitic magma conduits (ca. 1.86 Ga) in Wopmay orogen and slave craton: Petrogenetic constraints from whole rock and mineral chemistry

Seven <0.5 km2 ovoid ultramafic pyroxenite intrusions (pipes) occur in the internal zone of Wopmay orogen (Paleoproterozoic) and the western Slave craton (Archean), Northwest Territories, Canada. The intrusions occur intermittently over 120 km in a north-south trend that parallels the Wopmay fault zone. Field evidence and previously published Ar–Ar phlogopite results indicate they intruded at ca. 1.86 Ga, coincident with the latest-stages of deformation and magmatism in the Slave-Wopmay boundary zone. The intrusions are composed of early crystallized phenocrysts of olivine + chromite ± orthopyroxene, a groundmass of clinopyroxene that evolved to amphibole, and late-crystallizing phlogopite; the latter minerals are interpreted to result from relative hydration of the magmas during crystallization. Syn-magmatic sulphides occur but are not common and plagioclase is rare. The intrusions have arc-like bulk rock chemistry and when considered along with the mineralogy, these may represent cross-sections through spessartite lamprophyre magma conduits. The trace and rare earth element compositions of the silicate minerals are used to track the crystal-melt budget during crystallization of the intrusions in mid-to upper-crustal magma chambers. To account for mineral-chemical results and evolved Nd isotopes (εNd1860 -3 to −4), the magma source is interpreted as Archean lithospheric mantle that was fluid metasomatized in the spinel pyroxenite stability field. Although the intrusions are Paleoproterozoic and late- orogenic in nature, they were derived via polybaric partial melting of Slave craton mantle that was subcreted under the Wopmay orogen during the Calderian orogeny (1.88–1.86 Ga).

Regionally Correlated Oxygen and Carbon Isotope Zonation in Diagenetic Carbonates of the Bakken Formation

ABSTRACT Diagenetic minerals preserve records of burial processes that overprint records of seawater chemistry and impact reservoir porosity. The Mississippian-Devonian aged Bakken Formation in the Williston Basin is a reservoir rock of economic importance whose productivity is affected by diagenetic carbonates, particularly dolomite-ankerite-series carbonates. To investigate how diagenetic carbonate alteration manifests in the Bakken and how that might change across the basin, a combined δ18O and δ13C isotope dataset for diagenetic carbonates was collected by in situ SIMS analysis of 10-μm spots from nine drill holes covering a ∼250 km transect of the middle Bakken member. Observed core-to-rim isotopic variability in these small Fe-zoned dolomites and calcites frequently exceeds 10‰ in both δ18O and δ13C, indicating significant changes in thermal and chemical conditions during cementation. Individual ankeritic growth bands can be correlated across the basin by systematic similarities in minor-element compositions and isotope ratios. In the central part of the basin, δ18O and δ13C trends at sub-mm-scale decline consistently towards the rims of ankerite-series carbonates, which is interpreted to reflect mineral growth coincident with rising temperatures and an increasing organic contribution to inorganic carbon during burial. The most abrupt shifts in δ18O and δ13C (changes as large as 12‰ for δ18O and 6.5‰ for δ13C within distances

Temporal evolution of magma and crystal mush storage conditions in the Bárðarbunga-Veiðivötn volcanic system, Iceland

The depth(s) of magma storage reservoirs beneath active volcanic regions may change with time. Determining the rates and causes of millennial-scale changes in magmatic system architecture is critical for the development of realistic time-integrated models of crustal evolution. Here we examine a suite of samples from the exceptionally well-exposed Bárðarbunga-Veiðivötn volcanic system in central Iceland in order to resolve the temporal evolution of magma storage conditions within one of Iceland’s most productive volcanic systems. We have measured the major and minor elemental composition of glass, mineral and melt inclusion from five erupted units that span a full glacial cycle, from a <100 ka subglacial eruption to a historical eruption in 1477 AD. All samples contain macrocrysts (>500 μm), polymineralic clots and high-crystallinity nodules, consistent with derivation from crystal mush bodies. Macrocryst rims are in chemical equilibrium with their respective carrier melts, while macrocrysts cores are too primitive to have crystallized from these melts. Each sample records a distinct range of macrocryst compositions, indicating that the composition and/or eruptibility of stored crystal mush has changed with time. Macrocrysts from the oldest units are the most primitive, and the macrocryst compositional range becomes wider and, on average, more evolved, with time. Clinopyroxene-melt and melt-based (OPAM) geobarometers reveal temporally invariant crystallization conditions of 1.9–2.2 ± 0.7 (1σ) kbar pressure, corresponding to depths around 6.8–7.8 ± 2.5 km. All the samples also contain melt inclusions trapped at mid-crustal pressures of ∼2.6 kbar (9.6 km). In addition, melt inclusions hosted in most primitive olivines and plagioclases from subglacial and early Holocene eruptions preserve evidence of crystallization in a lower-crustal storage level(s) located at 17.5 km (4.9 kbar). This petrological record of deep crystallization may be linked to a surge in eruption rates, tapping of lower-crustal magma reservoirs, consistent with a crustal response associated with postglacial isostatic rebound. In contrast, the absence of a deep crystallization signature in the younger eruptive units may reflect lower magma production rates under steady-state conditions of the crust, and new magma pathways favouring melt storage in the mid-crust.

Petrogenesis of a Hybrid Cluster of Evolved Kimberlites and Ultramafic Lamprophyres in the Kuusamo Area, Finland

Abstract Kimberlites are often closely associated, both in time and space, with a wide variety of alkaline ultramafic rock types, yet the question of a genetic relationship between these rock types remains uncertain. One locality where these relationships can be studied within the same cluster is the Karelian craton in Finland. In this study we present the first petrographic, mineral and whole-rock geochemical results for the most recently discovered kimberlite cluster on this craton, which represents an example of the close spatial overlap of kimberlites with ultramafic lamprophyres. The Kuusamo cluster incorporates seven bodies [Kasma 45, Kasma 45 south, Kasma 47, Kalettomanpuro (KP), Kattaisenvaara (KV), Dike 15 and Lampi] distributed along a 60 km NE–SW corridor. Hypabyssal samples from KV, KP, Kasma 45 and Kasma 47 consist of altered olivine macrocrysts and microcrysts and phlogopite phenocrysts in a groundmass of perovskite, apatite, spinel, ilmenite, serpentine, and calcite. These petrographic features combined with mineral (e.g. Mg-rich ilmenite, Al–Ba-rich, Ti–Fe-poor mica) and whole-rock incompatible trace element compositions (La/Nb = 0·8 ± 0·1; Th/Nb = 0·07 ± 0·01; Nb/U = 66 ± 9) are consistent with these rocks being classified as archetypal kimberlites. These Kuusamo kimberlites are enriched in CaO and poor in MgO, which, combined with the absence of chromite and paucity of olivine macrocrysts and mantle-derived xenocrysts (including diamonds), suggests derivation from differentiated magmas after crystal fractionation. Samples from Lampi share similar petrographic features, but contain mica with compositions ranging from kimberlitic (Ba–Al-rich cores) to those more typical of orangeites–lamproites (increasing Si–Fe, decreasing Al–Ti–Ba), and have higher bulk-rock SiO2 contents than the Kuusamo kimberlites. These features, combined with the occurrence of quartz and titanite in the groundmass, indicate derivation from a kimberlite magma that underwent considerable crustal contamination. This study shows that crustal contamination can modify kimberlites by introducing features typical of alkaline ultramafic rock types. Dike 15 represents a distinct carbonate-rich lithology dominated by phlogopite over olivine, with lesser amounts of titaniferous clinopyroxene and manganoan ilmenite. Phlogopite (Fe–Ti-rich) and spinel [high Fe2+/(Fe2+ + Mg)] compositions are also distinct from the other Kuusamo intrusions. The petrographic and geochemical features of Dike 15 are typical of ultramafic lamprophyres, specifically, aillikites. Rb–Sr dating of phlogopite in Dike 15 yields an age of 1178·8 ± 4·1 Ma (2σ), which is considerably older than the ∼750 Ma emplacement age of the Kuusamo kimberlites. This new age indicates significant temporal overlap with the Lentiira–Kuhmo–Kostomuksha olivine lamproites emplaced ∼100 km to the SE. It is suggested that asthenospheric aillikite magmas similar to Dike 15 evolved to compositions akin to the Karelian orangeites and olivine lamproites through interaction with and assimilation of MARID-like, enriched subcontinental lithospheric mantle. We conclude that the spatial coincidence of the Kuusamo kimberlites and Dike 15 is probably the result of exploitation of similar trans-lithospheric corridors.

Trace element and mineral composition of Ediacaran-early Cambrian strata in South China and their geochemical implications

Ediacaran-early Cambrian is a critical interval in the evolution of atmosphere-ocean environment and biodiversity. The continuous Ediacaran-Cambrian strata in South China provide a good opportunity for investigating the associated environment with its ecological evolution. In this study, outcrop sedimentary rock samples collected from the Dongkanshang and Fengtan sections on the Yangtze Block were analyzed for their mineral and trace element compositions. The results showed some heterogeneity in the geochemistry of the Ediacaran-early Cambrian ocean in South China. Based on the U/Th, V/(V+Ni), V/Cr, and Ni/Co ratios, the middle-deep water was predominated by anoxic or euxinic condition with interferences from several transient oxidation events. The basinal Fengtan section indicates a more reduced depositional environment when compared with the slope Dongkanshang section. This shows that the seawater oxygenation was a gradual process that expanded from shallow to deep water.

Effect of Cassava Peel Based Diets on Performance and Meat Quality of Snail (Archachatina marginata Swainson)

The effect of cassava peel (CPL) incorporation (0,5, 10 and 15%) in the diets of growing snails (average initial weight 66.0 ± 0.15 g) on the growth performance, shell morphological changes, digestibility of nutrients, carcass yield and mineral element composition of the meat was investigated. The nutritional trial adopted four T1 (0%), T2 (5%), T3 (10%) and T4 (15%) almost isocaloric and isonitrogenous diets. Two hundred and forty growing snails were randomly allotted at 60 snails/treatment, while each treatment was replicated three times. The digestibility of nutrients was evaluated at the 12th of the fourteen-week trial. Data collected were analyzed in a complete randomized design using (ANOVA), a significant difference among the means was separated using Duncan's multiple range test. Cassava peel is rich in NFE (70.0%), low in crude protein (3.94%), while the four diets held almost equal proximate composition. Feed intake increased (P&lt;0.05) from T1 to T4 and T1 (control) had the best (P&lt;0.05) carcass yield. Survivability of snails at all levels was 100%. Highest dry matter digestibility (70.01%) was obtained in T1; the digestibility of other nutrients also reduced (P&lt; 0.05) with CPL incorporation. Meat mineral composition was not compromised by the treatments. Cassava peel based diet was favourably utilized at 15% CPL incorporation without any adverse effect on feed intake, growth, meat quality and carcass yield, farmers should adopt it.