Indicator Minerals Research Articles

Application of UAV-borne Magnetic Survey in Diamond Exploration: A Case Study over Kimberlite-Carbonatite Intrusion from Khaderpet, Eastern Dharwar Craton, South India

ABSTRACT Application of drone/unmanned aerial vehicle (UAV)-borne magnetometer (MagArrow) survey in diamond exploration is presented as a case study over diamondiferous kimberlite pipe intruded with carbonatite at Khaderpet within the Wajrakarur Kimberlite Field (WKF), south India. The kimberlite clan rock (KCR) of Kaderpet is expressed as a chloritised kimberlite- granite breccia that shows characteristics of an ultramafic lamprophyre. Owing to good response given by WKF kimberlites for magnetic surveys, a magnetic sensor is chosen in this investigation. Ten E-W traverses covering a total of 15- line km were conducted over an area admeasuring 1.8 sq. km in 35 minutes which may consume a week’s time in traditional ground magnetic survey. The acquired magnetic data revealed a strong magnetic ‘low’ of the order of -130nT in the reduced to the pole (RTP) image where carbonatite amidst granitoid- kimberlite breccia crops out. The magnetic ‘low’ anomaly of this survey matches with the KCR outline interpreted by earlier workers. The results of this survey have been verified with conventional ground magnetic survey which confirmed the presence of the anomaly (magnetic ‘low’) representing kimberlite granite breccia- carbonatite against a ‘high’ magnetic area represented by granitic/gneissic country rock in the surroundings. In this investigation, it is interpreted that the diamondiferous carbonatite hosted by granite chloritised kimberlite breccia is observed to extend to a depth of 7.3 to 41 m from the ground surface, which is consistent with the drilling results of previous exploration. This investigation showed that the drone-borne magnetic surveys can differentiate the anomaly/causative body within a background of country rock to locate anomalies corresponding to possible kimberlites and related rocks elsewhere in the cratonic terrains, provided other geological, geochemical and indicator mineral evidences also support.

Application of IR Fourier microscopy for investigation of kimberlite indicator minerals to search for diamond deposits using heavy-mineral concentrate method

Application of IR Fourier microscopy for investigation of kimberlite indicator minerals to search for diamond deposits using heavy-mineral concentrate method

Glacial dispersal of indicator minerals from the Brazil Lake LCT pegmatites, southwest Nova Scotia, Canada

The Brazil Lake lithium-cesium-tantalum (LCT)-type pegmatites (North, South, and Army Road pegmatites) in eastern Canada, were the focus of a detailed till study to document glacial dispersal of LCT pegmatite indicator minerals from bedrock. A total of 84 bulk (7-20 kg) till samples were collected from 77 sites around and down ice of the three pegmatites. The <2.0 mm fraction of the till samples was processed using shaking table and heavy liquid methods to produce 2.8-3.2 and >3.2 specific gravity (SG) non-ferromagnetic heavy mineral concentrates for visual identification and counting of indicator minerals in the 0.25-0.5 mm, 0.5-1.0 mm and 1-2 mm fractions. Glacial dispersal from the pegmatites is best defined by spodumene (the primary ore mineral) in the 0.25-0.5 mm fraction of the 2.8-3.2 SG concentrates, and its presence in the till (100s to 1000s of grains per sample) is visual confirmation of the existence of nearby LCT pegmatites. Glacial dispersal of spodumene forms a fan-shaped exploration target 12 km down ice that is considerably larger than the pegmatite subcrop areas. Other useful LCT pegmatite indicator minerals in the local till include apatite and tourmaline (10s to 100s of grains) and lesser amounts of columbite-tantalite, cassiterite, and scheelite (1s to 10s of grains), however, their abundances and spatial distributions are much less/smaller than that for spodumene. The results clearly demonstrate that indicator mineral methods are useful for Li exploration in the glaciated terrains of southwest Nova Scotia, across Canada, and other prospective glaciated terrains globally.

Genesis of the Wangu Au deposit in the Jiangnan orogenic belt: Constraints from texture, trace element, and in-situ Sr isotope of scheelite

Scheelite occurs widely in quartz vein-type Au deposits and serves as an indicator mineral for ore deposit genesis. The Wangu Au deposit, situated in the central part of the Jiangnan orogen belt, South China, is one of the largest Au deposits, with reserves exceeding 85 tonnes. Scheelite has been well-recognized within the Au-bearing quartz veins with a significant amount. To further elucidate the genesis of the Wangu deposit, this study focuses on scheelite to delineate the nature of ore-forming fluids and ore-forming material, by conducting TESCAN Integrated Mineral Analyzer (TIMA), cathodoluminescence (CL), Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) for texture, trace elements, and in-situ Sr isotope analyses.Scheelite from the Wangu Au deposit exhibits three texture-types: early homogeneous (Sch-I-1), oscillatory zones (Sch-I-2), and late veinlet (Sch-II). These different texture-type scheelites show a relatively flat to slightly MREE-enriched chondrite-normalized fractionation pattern, predominantly governed by the substitution mechanism of Ca2+=2REE3++□Ca (□Ca is a Ca site vacancy). Most positive and few negative europium (Eu) anomalies are observed for these different types of scheelite (0.5 to 46.7, mean 5.0), indicating Eu2+ is predominant over Eu3+. Together with the presence of methane in fluid inclusions within scheelite, indicating reduced nature of ore-forming fluids during its precipitation. All texture-types of scheelite have high Sr (383 to 12558 ppm, mean 3408 ppm) and low Mo (<1.7 ppm, mean 0.1 ppm) contents. In-situ Sr isotope data reveal that the 87Sr/86Sr ratios for Sch-I-1 range from 0.74601 to 0.76920, for Sch-I-2 ranging from 0.76485 to 0.76673, and for Sch-II ranging from 0.75627 to 0.75620. This high radiogenic Sr isotope composition of scheelite implies that fluid-rock interaction process is key to mineralization, and this process will add ore-forming materials from wallrock to the ore-forming system. Combined with the contribution of deep magmatic fluid inferred from the published isotope compositions such as H-O and He-Ar, we propose that W mineralization of Wangu deposit is associated with magmatic fluid, which is different from the classical orogenic Au deposit that formed from metamorphic fluid.

Identification of hydrothermal alteration mapping using spectral analysis of ASTER Data in NE Tohamiyam Area, Red Sea Hills, NE Sudan

The Tohamiyam area is located in the Red Sea Hills in East Sudan. Remote Sensing and GIS investigations were carried out in the study area using the ASTER data on VNIR and SWIR in mineral prospecting. It has increased recently because of its relatively low cost, broad coverage, and unique integral bands, susceptible to alteration minerals. The study aimed to delineate the hydrothermal alteration zones related to mineralization. The area is a part of the Haiya terrane (HT) of the late Proterozoic Arabian-Nubian Shield (ANS). The Haiya terrain consists predominantly of arc-back arc low-grade metavolcanic-sedimentary sequences decorated with dismembered ophiolitic rocks and intruded by granitoid intrusions of different ages. The ASTER semi-hyperspectral data have been treated with a Mixture Tuned Matched Filtering (MTMF) classifier. The MTMF classifier matches the spectral signatures of the indicator minerals with similar spectra from the ASTER–USGS spectral library. MTMF classifier images portrayed at least many sites as highly probable alteration mineralization zones in the NE part of the study area, which conforms with the results obtained from Aster data. This study revealed that the results of mineral prospecting investigations obtained from ASTER data show that they can distinguish the spectral signatures of the indicator minerals and delineate the alteration halos related to mineralization zones. The results of remote sensing applications with field geochemical data show that the spectral and spatial analysis of optical semi-hyperspectral data in mineral exploration investigations is strengthened. This study recommends remote sensing and machine learning technology in mineral studies through hydrothermal alteration within the basement complex rocks of the Nubian Shield in Red Sea hills.

Alternative gold prospecting methods used by artisanal and small scale miners: A review

Artisanal and Small Scale Mining (ASM) is distinctive to Industrial Mining (IM) upon minimal applications of scientific methods and inadequate funding of its geological exploration activities. Revision of scholarly sources indicate that for ASM, gold prospecting is done using visual features that signify zones of mineralization. Such features comprise soil and lithological indicators, geo-biotic indicators, indicator minerals, pathfinder elements and associate minerals. Others include physical features and mine vestiges. Imminent research on ASM rests upon studying scientific inter-relationships of such techniques and suitable mechanisms of financing activities related to geological exploration, an inordinate barrier to smart productivity of ASM.

Active Hyperspectral Scanning of Rock Face with a Supercontinuum Laser

Underground environments present a challenge for hyperspectral outcrop analysis. In addition to operational safety and moisture, illumination is the main concern in data acquisition. We report a supercontinuum laser for illuminating rock faces in hyperspectral data acquisition. We present the early results of combining an off-the-shelf hyperspectral camera with a supercontinuum laser system, measured at night on rock faces in a former open-pit mine in southeast Spain as a proxy for underground lighting conditions. Band ratios specifically developed for this geological setting and low-light conditions highlight key minerals that can be used as a vector toward the ore zone. We successfully highlight the key indicator minerals and their distribution patterns for defining gold-bearing ore zones and that supercontinuum white laser light is a feasible illumination source for hyperspectral line scanners under field conditions.

Analysis of nano-mineral chemistry with single particle ICP-Time-of-Flight-MS; a novel approach to discriminate between geological environments

Studies of indicator minerals and mineral chemistry are widely used in geochemistry and are particularly useful in mineral exploration. Due to the low abundance of indicator mineral grains, large field samples and extensive laboratory processing are required for these studies. However, nano- and submicron-scale mineral particles (NPs, diameter < 1 μm) are highly abundant in geochemical sample media, containing millions to billions of particles per gram of soil or sediment. In this study, we analyze mineral NPs using single particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS), a recently developed technique for high throughput elemental characterization of NPs. We investigate the limitations of the technique that arise from the working range of the ICP-TOFMS instrument and the analytical uncertainty of measured element masses in single particles. Despite these limitations, spICP-TOFMS can be used to determine accurate element mass ratios in NPs, which we validated through analysis of mineral specimens. Elemental mass ratios obtained from spICP-TOFMS in the mineral specimens were supported by SEM-EDS. We analyzed the mineral chemistry of two pairs of elements, ZrHf and NbTa in geochemical samples (sediments, soils, and mine waste) adjacent to a carbonatite and a lithium‑cesium‑tantalum-type pegmatite. Hundreds to thousands of NPs were detected in only 30–80 min of spICP-TOFMS analysis, indicating that these particle types are highly abundant. Pegmatite-associated samples contained Hf and Ta-rich NPs, compared to carbonatite-associated samples that displayed the chondritic or crustal abundance mass ratios in single particles. Zr:Hf mass ratios measured in NPs by spICP-TOFMS were supported by LA-ICP-MS analysis of zircons from selected samples. Diagnostic nano-mineral compositions including Nb-Ta-Bi-Sb (large grains of which are rarely found) were abundant in pegmatite-associated samples, but virtually absent in carbonatite-associated samples. In this study, we demonstrate that the chemistry of mineral nanoparticles can be used to discriminate between geological environments, and for the first time, we show that spICP-TOFMS is an effective tool for this type of analysis.

Intra-grain variability of hydrogen and trace elements in rutile

Rutile is a commonly used petrogenetic indicator mineral to determine metamorphic temperatures, ages, host−/source lithologies, geochemical reservoirs, and subduction conditions. However, intra grain variabilities of trace elements in rutile are rarely considered. We performed trace element and hydrogen mapping of rutile to assess zoning and diffusion in natural rutile from various lithologies. Trace element and hydrogen show distinct zoning patterns, with mostly regular zoning in rutile from pegmatites and low-T hydrothermal clefts, and typically irregular zoning in rutile from high-P veins and metamorphic rocks. Whereas no clear patterns of trace element correlations can be identified, hydrogen, tri-, tetra- and pentavalent cations can show the same zoning patterns within single rutile grains, despite different substitution mechanisms. This indicates that hydrogen and trace element incorporation is externally controlled by availability and diffusivity of hydrogen and trace elements within the rock matrix, as well as rutile growth rates. H2O mapping reveals that hydrogen is retained in rutile at temperatures of up to ∼650 °C. Coupled substitution of hydrogen with divalent and trivalent cations requires coupled diffusion processes for charge balance if hydrogen is diffusively re-equilibrated. Slow diffusion rates and thus relatively high temperatures for diffusive closure in rutile lead to retention of primary hydrogen and trace element zoning. At high-T conditions of >650 °C, diffusive re-equilibration of all trace elements can be observed. Complex zoning patterns of Zr in rutile show that Zr incorporation into rutile is not purely temperature dependent. In this study, Zr-undersaturation can lead to inaccurate Zr-in-rutile temperatures of up to ∼35 °C difference from peak formation temperatures within single rutile grains and might be a useful tool to evaluate rutile growth conditions. Niobium and Ta are highly zoned in rutile, leading to extremely variable Nb/Ta ratios within single rutile grains that cannot be reconstructed from single spot analyses. Overall, mapping offers a novel and promising tool to understanding trace element behavior in rutile.

Evaluation of Granite Fertility Utilizing Porphyry Indicator Minerals (Zircon, Apatite, and Titanite) and Geochemical Data: A Case Study from an Emerging Metallogenic Province in the Taimyr Peninsula, Siberian High Arctic

The Taimyr Peninsula in the Russian High Arctic comprises a late Paleozoic-early Mesozoic collisional belt where several porphyry-type mineralization occurrences were identified during the last decade, making this area a potential exploration target for Cu-Mo deposits. In order to further evaluate the metallogenic potential of the poorly outcropped northeastern part of Taimyr, samples from seven granitoid intrusions were investigated in this study aimed to evaluate the granite fertility based on petrography, geochemistry, and composition of porphyry indicator minerals (zircon, apatite, and titanite). The studied intrusions represent small to moderate-sized bodies (40–800 km2) composed of biotite (±amphibole) quartz monzonites, granodiorites, granites, and biotite leucogranites that formed in the course of late Paleozoic-early Mesozoic tectono-magmatic events at the Siberian margins. The late Carboniferous Tessemsky massif represents suprasubduction granitoid series, while the Pekinskiy, Shirokinskiy, Dorozhinskiy, Kristifensenskiy, and Yuzhno-Lodochnikovskiy massifs are correlated with the early Triassic Siberian Traps LIP. The rocks of intrusions comprise a relatively uniform geochemically, predominantly magnesian, slightly peraluminous, calc-alkaline high-K amphibole-bearing I-type granitoid series with adakitic affinity, where Triassic plume-related granitoids inherit geochemical signatures of Carboniferous supra-subduction granitoids, and all rock types are marked by enrichment in LILE and negative Ta, Nb, and Ti anomalies. It is suggested that the adakitic geochemical characteristics of the Taimyr granites are a result of derivation from a relatively homogeneous mafic lower crustal source that formed at the stage of Carboniferous continental subduction and continued to produce granitic melts in the course of the early Mesozoic magmatic evolution. Whole rock geochemistry and composition of porphyry mineral indicators (zircon, apatite, and titanite) indicate that the Taimyr granites crystallized from oxidized water-saturated magmas at moderate temperatures, with the majority of samples showing characteristics typical for porphyry-fertile granites worldwide (fO2 = ΔFMQ +1 to +3 with zircon Eu/Eu* &gt; 0.4 and apatite SO3 &gt; 0.2 wt.%). Data from Dorozhinskiy, Kristifensenskiy, Pekinskiy, and Tessemskiy intrusions fully match geochemical criteria for porphyry-fertile granitoids, and these massifs are considered the most prospective for Cu-Mo mineralization. Granites from Shirokinskiy and Yuzhno-Lodochnikovskiy intrusions only partially match compositional constraints for fertile melts and can be considered as second-tier exploration targets. Finally, available data for the Simsovsky massif preclude its classification as a porphyry-fertile body. These conclusions are in line with previously developed exploration criteria for the northeastern Taimyr, showing that geochemical indicators of granite-fertility can be used on a regional scale in parallel with other exploration methods.

Advanced exploration of rare metal mineralization through integrated remote sensing and geophysical analysis of structurally-controlled hydrothermal alterations

Fusing multi-source (remote sensing and geophysical) data and diverse approaches validation in targeting hydrothermal alteration and structural anomalies enhances the potential for accurately detecting and characterizing mineralization zones. Sentinel 2 data and ASTER were processed for lithological and hydrothermal alteration mapping in the rare metal-rich Umm Naggat area (Egypt). Different image processing techniques were implemented, including false color composites, minimum noise fraction, band rationing, band math, mineral indices, relative absorption band depth, and constrained energy minimization. The rare metal-bearing Umm Naggat younger granite (NYG) pluton was lithologically discriminated and intra-differentiated to mafic-rich biotite granites, mafic-poor alkali feldspar granites, and albitized granites. Extensive hydrothermal alterations, such as albitization, ferrugination, propylitization, argillization, and phyllitization, overprint the NYG pluton. Normalized standard deviation, automatic lineament extractions, and trend analysis highlighted the key structural directions (NW, NNW, NNE, and NE) and distinguished the NYG pluton as a moderate to high structural density zone. The high structural density and intensive alteration zones are spatially associated and more localized within the NYG pluton than the surrounding rocks. Spatial overlay analysis confirmed that the hydrothermal alterations and fluid circulation systems are structurally-controlled. Furthermore, the hydrothermal alteration mapping and structural analysis outcomes were verified by combining fieldwork, slab polishing, petrographic investigations, and mineral chemistry through semi-quantitative scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and quantitative electron probe microanalysis (EPMA) analysis. As a result, the hydrothermal genesis of rare metal-bearing minerals (Nb-rutile, Nb-ilmenite, and columbite) close to or incorporated within alteration minerals (chlorite, muscovite, and hematite) is confirmed from the alteration zones (propylitic, phyllic, and ferruginated). In addition, biotite muscovitization and chloritization significantly contribute to the secondary rare metal enrichment. The current study emphasizes the extensive distribution of secondary rare metal-bearing minerals within the entire NYG pluton (not only limited to the northern albitized granite as depicted by previous studies), which might shed light on these hydrothermally-altered younger granites as a new potential source for Nb and Ta in Egypt.

Magnetite Survivability and Non‐Stoichiometric Magnetite Formation in Presence of Oxyhalogen Brines on Mars

AbstractThe mixed Fe(II)/Fe(III) mineral magnetite [Fe3O4] of various stoichiometric and non‐stoichiometric compositions have been reported in Martian soils and rocks by several rover missions. Magnetite is an important paleomagnetic indicator mineral and can serve as a ‘biogeobattery’ as a consequence of its magnetic properties and the mixed valence state of iron in its structure. Here, we assess the extent of oxidative weathering of magnetite in presence of chlorate and bromate containing solutions that are likely important oxidants on Mars. Oxyhalogen species, chlorate and bromate, produced non‐stoichiometric magnetite [Fe(II)/Fe(III) &lt; 0.5] in Mars‐relevant, near‐neutral pH fluids; no other ferric minerals were produced. The same results were observed in highly acidic fluids with or without oxyhalogens. Owing to its resistance to extensive oxidation, magnetite can serve as an important archive of geochemical, paleomagnetic, and astrobiological information in samples that will be returned by the Mars Sample Return mission.

Physico-thermal and geochemical behavior and alteration of the Au indicator gangue hydrothermal quartz at the Kubi Gold ore deposits

Altered and gangue quartz in hydrothermal veins from the Kubi Gold deposit in Dunkwa on Offin in the central region of Ghana are investigated for possible Au-associated indicator minerals and to provide the understanding and increase the knowledge of the mineral hosting and alteration processes in quartz. X-ray diffraction, air annealing furnace, differential scanning calorimetry, energy dispersive X-ray spectroscopy, and transmission electron microscopy have been applied on different quartz types outcropping from surface and bedrocks at the Kubi Gold Mining to reveal the material properties at different temperatures. From the diffraction results of the fresh and annealed quartz samples, we find that the samples contain indicator and the impurity minerals iron disulfide, biotite, titanium oxide, and magnetite. These minerals, under oxidation process between 574 and 1400 °C temperatures experienced hematite alterations and a transformation from α-quartz to β-quartz and further to cristobalite as observed from the calorimetry scans for hydrothermally exposed materials. The energy dispersive spectroscopy revealed elemental components of Fe, S, Mg, K, Al, Ti, Na, Si, O, and Ca contained in the samples, and these are attributed to the impurity phase minerals observed in the diffraction. The findings also suggest that during the hydrothermal flow regime, impurity minerals and metals can be trapped by voids and faults. Under favorable temperature conditions, the trapped minerals can be altered to change color at different depositional stages by oxidation and reduction processes leading to hematite alteration which is a useful indicator minerals in mineral exploration.

New capabilities of application of gamma-ray logging in borehole geophysical investigations through steel string

Borehole geophysical investigations through steel string (both drill and casing) are becoming increasingly important. Gamma-ray logging (GR) is a mandatory and one of the main methods for investigating oil-and-gas reservoirs and near-surface rocks. It is characterized by high efficiency under the aforementioned measurement conditions. GR is used to identify bed boundaries, evaluate lithology, estimate shaliness, identify reservoirs, etc. Traditionally, the determination of granu- lometric shaliness is the main goal of quantitative interpretation for GR. Gamma-ray logging has been successfully used for many decades. However, increasing the accuracy of determining granulometric shaliness, expanding the informativeness of the method to determine mineral clayness, and developing procedures for using GR data in estimating other petrophysical parameters are topical issues. Based on logging materials, the paper examines the features of using the main interpretation parameter of GR (the relative difference parameter – index ΔІγ) in boreholes in the presence of a steel column and proposes new methodological approaches to the use of GR data when interpreting measurements in oil-and-gas and engineering-geological boreholes. Through numerous ex- amples, the invariance (constancy) of the interpretation parameter of gamma-ray logging has been proven under different borehole conditions, types of logging tools, etc. An approach has been proposed for obtaining optimal reference values when determining this parameter, which increases the accuracy of estimating shaliness parameters. A method has been developed for determining mineral clayness, which is an important quantity in itself and is necessary for determining other petrophysical parameters from loggingdata. A multiplicative method has been created for determining the total porosity of shaly rocks using a combination of neutron logging and gamma-ray logging, which makes it possible to avoid using the hydrogen index of clay minerals. The novelty of the developments is supported by patents, and their effectiveness is confirmed by the results of borehole tests and comparisons with independent determinations of parameters (laboratory core studies, traditional methods of interpretation). The proposed approaches are an important component of the investigation technologies for oil-and-gas reservoirs and near-surface rocks, developed at the Institute of Geophysics of the National Academy of Sciences of Ukraine.

Study on the evaluation of shale reservoir brittleness based on mineral disorder

Brittleness serves as a critical indicator for assessing whether reservoirs can form complex fracture networks. While methods based on brittle mineral content or rock mechanical parameters are widely used, their lack of integration between mineralogy and mechanics introduces limitations. A single evaluation parameter cannot accurately assess shale brittleness. There is a need for a universally applicable method that comprehensively considers mineral composition, mechanical properties, and brittleness variations in shale evaluation. This study uses Longmaxi shale in the Sichuan Basin as an example, establishing a mineral disorder index based on shale mineral composition and mechanical characteristics, incorporating the influence of confining pressure to establish a shale brittleness index. Results indicate varying weights of brittleness contributions from different minerals, ranked in descending order: pyrite, quartz, calcite, dolomite, feldspar, and clay. Greater complexity in mineral combinations correlates with lower shale brittleness indices. Typically, single mineral disorder indices show a positive correlation with internal mineral disorder indices. Confining pressure exhibits an inversely proportional relationship with shale brittleness indices, with brittleness at 30, 50, and 70 MPa confining pressures being 0.737, 0.586, and 0.451 times those without confining pressure, respectively. This method guides current brittleness research and reservoir production enhancement.

Determination of a normal orogenic palaeo-geothermal gradient with clay mineral and organic matter indices: a review

A collection of large data sets from different orogenic belts was compiled for a correlation between organic matter (OM) versus clay mineral (CM) indices calibrated with the vitrinite reflectance, (VR) vs Kübler-Indices (KI) method. Data selection was based on a normal geothermal gradient (25 to 35 °C/km) as determined in previous studies, e.g. by maturity modelling and clay mineral reaction progress calculations. In the Lower Austroalpine (Eastern Switzerland, European Alps) a 20 myr lasting metamorphic overprint caused an OM–CM thermal equilibrium among the indices used. The observed correlation enables to determine gradual changes in metamorphic factors such as pressure, temperature and time causing sensitive shifts of the gradient slope in the range of normal gradients. For New Caledonia, an identical correlation has been determined. Prior to re-equilibration of the VR/KI indices, sediments in New Caledonia of diagenetic to incipient metamorphic grade underwent a high-pressure subduction event. VR/KI indices are in or close to equilibrium, while slight differences in OM vs CM indices allow for a better understanding of polyphase conditions, especially with respect to pressure. Temperature estimations are identical despite of their poly-phase metamorphic history, which was mainly controlled by the last orogenic thermal event lasting > 5 to < 10 myr. In the eastern Helvetic Alps and Northern Calcareous Alps similar correlations were found with slightly different slopes. Comparison between different regions is possible when using KI standardization and same data discrimination. In both parts of the Alps a complex thermal history of short durations (< 5.0 myr for the Northern Calcareous Alps to 10 myr for the Helvetic Alps) caused similar VR/KI trends, but disequilibrium is suggested by weaker regression parameters. The following correlation is calculated for a moderate geotherm (55 to 74 mWm2, mean = 61 mWm2) and normal temperature gradient conditions (25 to 35 °Ckm−1): KI = 1.134e−0.305VR, (R2 = 0.880, n = 462) with VR given as %Rmax, KI as Δ°2θ (limited to values between 0.2 to 1.0 Δ°2θ). With increasing depth (z) a VR gradient of 1.4 ± 0.2%Rmaxkm−1 is determined and a KI gradient of 0.09 ± 0.002 Δ°2θ km−1 is observed. The study illustrates that a normal geotherm can be described by VR/KI correlation, even if different heating episodes may occur. For the detection of a poly-phase or plurifacial thermal history, several indices of clay minerals and organic matter with very different kinetics should be used, as e.g. demonstrated by strong differences in smectite content at equal VR/KI values versus structural depth. A specific interest is given to the correlation of vitrinite like solid bitumen reflectance as an alternative method to VR, the persistent preservation of liptinite macerals and the stability range of clay minerals and sub-greenschist facies critical minerals compared with VR/KI data. Until now, despite the Alps in this study, systematic liptinite maceral studies have not been published in other orogenic settings.

THE POTENCY OF INORGANIC SELENIUM SUPPLEMENTATION ON SERUM, ANTIOXIDANT AND MINERAL INDICES OF HEAT STRESSED BROILER CHICKS

A research was conducted to investigate the potency of inorganic selenium supplementation on serum, antioxidant and mineral indices of broiler chicks during heat stress. Two hundred and fifty six, 1-day old chicks were randomly allotted to four experimental treatments (0, 0.1 0.2 and 0.3 mg of Se/kg), with four replicates each in a Completely Randomized Design. Results indicated a similarity (P&gt;0.05) among all treatment groups. In conclusion, during period of heat stress, selenium can be supplemented in the diet of broilers at levels ranging between 0.1-0.3mg/kg diet.

A critical review on the efficacy of Kodo, Sorghum, and foxtail millets in the management of type 2 diabetes mellitus

Diabetes mellitus (DM) affects around 537 million people globally, with 77 million cases in India. Type 2 DM is primarily linked to poor dietary habits and sedentary lifestyles, leading to either insulin resistance or impaired insulin secretion. In Ayurveda this condition is referred to as Apathyanimmataja Prameha. To promote healthier food choices, the Indian government declared 2023 as the International Year of Millets, emphasizing their significant health benefits. Historically, millets, known as "Shri Anna," were among the first domesticated crops in India and were a staple food across Asia. However, with the Green Revolution prioritizing the mass production of rice and wheat, millet cultivation declined. Millets are classified as "Nutri Cereal" due to their low glycemic index (GI), gluten-free nature, and rich content of flavonoids, vitamins (E, B complex), minerals, and antioxidants. They help prevent various lifestyle diseases and have demonstrated antidiabetic effects. Specifically, Kodo, Sorghum, and foxtail millets have shown significant impact on controlling hyperglycemia, as confirmed by studies. Ayurvedic texts also recommend these millets as a wholesome diet, particularly in managing conditions like Prameha (diabetes) and obesity. This article draws data from Ayurvedic texts, previous dissertations, and electronic databases like ResearchGate and PubMed and Google Scholar. It explores the pharmacodynamic properties of Kodo, Sorghum, and foxtail millets focusing on their preventive and therapeutic effects in managing type 2 DM by integrating both Ayurvedic and modern scientific research.

Integrating remote sensing and geophysical data for mapping potential gold mineralization localities at Abu Marawat area, central Eastern Desert, Egypt

Abu Marawat area in the Central Eastern Desert of Egypt is a very promising mineralization district located in the Golden Triangle area. The current study provides an integrated approach from multisource datasets including; remote sensing, airborne geophysical spectrometry and magnetic data supported by field studies and spectroscopic analyses for delineating potential mineralization localities. Several remote sensing techniques were adopted including; Band Ratios, Relative Band Depth, Mineralogical Indices, Spectral Angle Mapper, and Constrained Energy Minimization. These techniques showed that the alteration mineral assemblage is mainly, kaolinite, sericite, and iron oxides, with less abundant chlorite, epidote, and carbonates. In addition, the radiometry data were processed to map the localities with the highest possibility of potassic alteration abundance by integrating the potassium distribution, K/eTh ratio, and the F-parameter maps. The surface and subsurface linear structural features were also mapped using Digital Elevation Model (DEM) and aeromagnetic data, respectively. The surface linear structures were found exhibiting E-W and NE-SW trends, while, the subsurface structures showed dominant NW–SE trend. All the depicted fault trends match well with the local and regional geological and tectonic setting of the study area suggesting structural control on the mineralization in this area. Integration between the results obtained from both the remote sensing and the geophysical data was conducted by a GIS weighted overlay model. The obtained mineralization potentiality map highlights eight potential localities for mineralization. The accuracy of the adopted methodology was demonstrated through fieldwork and spectral analyses; several alteration indicators were observed, including quartz veins, iron oxides, kaolinite, malachite, montmorillonite, chlorite, talc, and sericite alteration indicator minerals. The adopted remote sensing-geophysical approach showed being very effective for mapping the hydrothermal gold-related alteration zones, and is recommended for other similar investigations.

Natural variation in the nutritional composition of African baobab (Adansonia digitata L.) from two ecological sites in Northern Malabar, Kerala, India

Adansonia digitata L., commonly known as the African baobab, is an important plant within the Malvaceae family. It is a highly nutritious forest tree and holds a special place in several African countries. Despite its prevalence in Africa, its presence is very limited in India, and only a few individual plants of this species are reported from different parts of India, including Kerala. This study focuses on the plants growing at Ajanur and Thalassery in the Kasaragod and Kannur districts of Kerala, respectively. This study reports natural variation in phytochemicals, minerals, and the proximate components of its flowers and leaves at these locations. The results of this study show that total carbohydrate (28.79 %), crude fibre (10.76 %), and protein (53.09 %) content was higher in leaves at Ajanur. In contrast, chlorophyll a, b, and carotenoid content were highest in leaves at Thalassery and showed a value of 39.03 mg/g, 16.65 mg/g, and 13.21 mg/g, respectively. The highest quantity of elements viz. Ca, Zn, K, Fe, Cu, Ni, and Cr were reported in leaves from Thalassery, whereas Mg and Mn were abundant in the leaves from Ajanur. Flowers from Ajanur demonstrated a superior nutritional index, while Thalassery leaves exhibited a higher mineral index. Assessment of antioxidant activity indicated the highest DPPH scavenging activity in the leaves from Ajanur (IC50 = 102.57 μg/mL) and the highest ABTS scavenging activity in its flowers from Thalassery (IC50 = 62.74 μg/mL). The differences in nutritional components and antioxidant properties of the baobab from these two ecological sites underscore the role of ecological factors in its natural variation. Although it is an important forest food tree in the African continent, its potential contribution towards food security from the Indian subcontinent remains untapped.