Till Samples Research Articles

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.

Derivation of Predictive Layers Using Regional Till Geochemistry Data for Mineral Potential Mapping of the REE Line of Bergslagen, Central Sweden

With the increasing need for rare-earth elements (REEs) to reach the goals of the ongoing green energy transition, new and innovative methods are needed to identify new primary resources of these critical metals. This study explores the potential to use a non-biased, uniform till dataset to generate evidentiary layers that describe these critical factors and geochemical anomalies to aid mineral potential mapping (MPM) for REEs using machine-assisted methods. The till samples used in this study were collected from the “REE Line”, a sub-region within the Bergslagen lithotectonic province, Sweden, where numerous REE mineralizations occur. Multiple approaches were used in this study to isolate geochemical anomalies using multivariate methods, namely principal component analysis (PCA) and K-means clustering. Additional factors for classifying till samples were also tested, including alteration indices. Using known REE occurrences in Bergslagen as validation points, the results demonstrated the usefulness of multivariate methods applied to till geochemistry for predictive bedrock mapping, and to identify potential areas of REE mineralization within the REE line. The results of the alteration indices showed that the till geochemistry demonstrated similar levels of alteration when compared to the underlying bedrock, allowing for a regional alteration map to be generated. These results show that regional-scale till sampling can provide low-cost data for mineral exploration at the regional scale and generate usable evidentiary layers for GIS-based MPM.

Pengzhenrongella phosphoraccumulans sp. nov., isolated from high Arctic glacial till, and emended description of the genus Pengzhenrongella.

A yellow pigmented, Gram-stain-positive, motile, facultatively anaerobic and irregular rod-shaped bacteria (strain M0-14T) was isolated from a till sample collected from the foreland of a high Arctic glacier near the settlement of Ny-Ålesund in the Svalbard Archipelago, Norway. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that M0-14T formed a lineage within the family Cellulomonadaceae, suborder Micrococcineae. M0-14T represented a novel member of the genus Pengzhenrongella and had highest 16S rRNA gene sequence similarity to Pengzhenrongella sicca LRZ-2T (97.3 %). Growth occurred at 4-25 °C (optimum 4-18 °C), at pH 6.0-9.0 (optimum pH 7.0), and in the presence of 0-5 % (w/v) NaCl. The predominant menaquinone was MK-9(H4) and the major fatty acids were anteiso-C15 : 0, C16 : 0 and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were phosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylinositol, one undefined phospholipid and five undefined phosphoglycolipids. The cell-wall diamino acid was l-ornithine whereas rhamnose and mannose were the cell-wall sugars. Polyphosphate particles were found inside the cells of M0-14T. Polyphosphate kinase and polyphosphate-dependent glucokinase genes were detected during genomic sequencing of M0-14. In addition, the complete pstSCAB gene cluster and phnCDE synthesis genes, which are important for the uptake and transport of phosphorus in cells, were annotated in the genomic data. According to the genomic data, M0-14T has a metabolic pathway related to phosphorus accumulation. The DNA G+C content of the genomic DNA was 70.8 %. On the basis of its phylogenetic relationship, phenotypic properties and chemotaxonomic distinctiveness, strain M0-14T represents a novel species of the genus Pengzhenrongella, for which the name Pengzhenrongella phosphoraccumulans sp. nov. is proposed. The type strain is M0-14T (= CCTCC AB 2012967T = NRRL B-59105T).

Pore structure analysis of glacial till under freeze-thaw cycles based on calibration CT data

ABSTRACT Acquiring the interior pore characteristics is essential to the utilisation of glacial till which is the material of permeability barrier to many engineering projects in cold regions. In this work, the pore space of glacial till samples with different cementation degrees and freeze-thaw cycles was investigated by CT technique. Representative elementary volume method (REV) was utilised to ensure a suitable scale of CT volume data, and a novel calibration method was proposed to detect the accuracy of CT segmentation. Subsequently, the effect of cyclic freeze-thaw action on the pore structure of glacial till samples was investigated. Quantitative pore structure analysis shows that cyclic freeze-thaw action resulted in a decrease in porosity of both well cemented and poorly cemented glacial till. The accessible porosity, fractal dimension, and coordination number of glacial till pores also decrease with the increment of freeze-thaw cycles. It can be observed that blocking of the channels of macropores is the main morphological evolution characteristic of glacial till with cyclic freezing and thawing, which can provide reference in designing permeability barrier in glacial till layers.

Principal components analysis and K-means clustering of till geochemical data: Mapping and targeting of prospective areas for lithium exploration in Västernorrland Region, Sweden

To achieve the demand for elements used for the green transition energy, such as lithium, it is necessary to recognize the spatial distribution of the concentrations of these elements in different earth materials such as bedrock and soil and to identify areas with anomalous concentrations of such elements (i.e., mineralization) for further exploration and hopefully exploitation. This study carried out multivariate statistical analyses on compositional (i.e., element concentration) data from till samples to recognize areas that likely contain lithium pegmatite mineralization in the Västernorrland region, central Sweden. We applied principal components analysis (PCA) and K-means clustering techniques to reveal regional-scale patterns in the till geochemical data. We demonstrate that these two methods have potential for recognition of geochemical anomalies related to the underlying bedrock geology as well as to mineralization. The results of PCA- and K-means clustering were validated using known occurrences of lithium mineralization. Two different datasets were compared; one containing all available geochemical data and the second containing only available trace elements in the dataset and it was found that anomalous clusters of samples defined by K-means clustering have anomalous multi-element signatures defined by robust PCA. This demonstrated that principal components are the continuous solutions to the discrete cluster members for the K-means clustering. The results show that both PCA and K-means clustering of till geochemical datasets at the early stages of exploration and target generation may reveal useful information that can be used to identify potential areas for more detailed mapping or exploration activities.

The Pleistocene ice-sheet dynamics in north-central Poland based on magnetic fabrics of tills and landform analysis

Abstract This research was carried out in north-central Poland, which was occupied by the ice sheet of the Saalian (Marine Isotope Stage [MIS] 6) and Upper Stadial of the Weichselian (MIS 2) glaciation. The application of the anisotropy of magnetic susceptibility (AMS) method supported by a digital elevation model (DEM) analysis of the orientation of glacial landforms allowed for the reconstruction of ice-sheet extent and ice movement directions of these two Pleistocene glaciations. The research used an innovative method of collecting AMS till samples from the glacial plateau areas. Based on the research, it was found that during the general recession of the ice sheet of the Saalian glaciation, a previously undescribed glacial transgression occurred, characterized by a different direction of ice-sheet movement. On the basis of detailed geomorphological studies of the area of terminal moraines, previously described in fragments, the maximum extent of the ice sheet during the Weichselian glaciation was clarified. The recession of the ice sheet of the Weichselian glaciation from the area of north-central Poland took place in four regressive or transgressive–regressive stages with variable directions of ice-sheet movement. The results obtained indicate the great potential of the AMS method in paleoenvironmental studies of glaciated areas.

From Rocks to Pixels: A Protocol for Reproducible Mineral Imaging and its Applications in Machine Learning

Identifying minerals is essential for geology, mineral exploration, engineering, and environmental sciences. Recent advances in machine learning have illustrated its potential as a fast, cost-effective, and reliable tool for identifying minerals from photographs or photomicrographs. However, in the recent literature, few studies have been dedicated to image acquisition. Machine learning generally requires reproducible, high-quality data to perform complicated tasks such as mineral identification to avoid common pitfalls. In this paper, we propose a practical image acquisition protocol for optical microscopes. This protocol focuses on ensuring reproducibility and enhancing image quality. To favor reproducibility, we detail dealing with camera errors, using reference color gauges, and establishing experimental parameters such as the external light source and temperature. For image enhancement, we explain the importance of lighting and its impact on machine learning precision, selection of the objective, and white balance calibration. In addition, we trialed the protocol on heavy mineral concentrate from till samples (20 species) with a typical deep learning model and it revealed that minor lighting modification (<5% difference in one channel) significantly increased misclassification rates: kyanite from 6.4% to 24.9% and monazite from 6.5% to 42.9%.

Review of till geochemistry and indicator mineral methods for mineral exploration in glaciated terrain

Since the 1970s, till geochemical and indicator mineral methods for mineral exploration, provenance studies and environmental research in glaciated terrain have been developed, tested and refined. This review summarizes these methods, focusing on field and laboratory methods for till geochemical, indicator mineral and boulder surveys. This review of protocols is intended as a guide for the mineral exploration industry and publicly funded agencies. It summarizes till as a sample medium, and describes the formation of glacial dispersal trains, along with methods for till sample collection, sample processing, matrix geochemistry, indicator mineral analyses, quality assurance/quality control procedures and data reporting and interpretation. The methods described here can be used to conduct reconnaissance- to deposit-scale till sampling surveys to assess mineral resource potential and establish environmental baselines. Supplementary material: Appendix A – Photographs of till types described in text; Appendix B – Logistical and geological factors to consider in till sample survey design; Appendix C – Photographs of glaciate terrain types described in text; and Appendix D – Till sample processing and analysis flow charts are available at https://doi.org/10.6084/m9.figshare.c.6786087 Thematic collection: This article is part of the Reviews in Exploration Geochemistry collection available at: https://www.lyellcollection.org/topic/collections/reviews-in-exploration-geochemistry

Building geochemical vectors with trace element compositions of sulfides in orogenic gold mineral systems in northern Finland

Exploring and discovering new ore deposits that supply the needed metals for our current societal transition to a green-energy and technologically advanced low-carbon future is becoming increasingly difficult. To fully convert the current system however, a significant increase of mining of minerals is required, particularly since current global mineral reserves are insufficient to cover the growing demand for a fossil fuel-free infrastructure. It is therefore even more important to develop and introduce new time-and cost-efficient exploration tools, which can be utilized in the discovery of new mineral deposits and applied in the early, or through advanced stages of mineral exploration. Given that Finland is one of the major EU countries that covers the supply chain for the EU battery industry, its metallogenic provinces are extensively tested and investigated by new exploration technologies. For this purpose, a comprehensive dataset of trace element contents in single grains of pyrite, pyrrhotite and chalcopyrite was compiled on the basis of results of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) analyses. Samples were systematically collected from drill cores from orogenic Au-only and Au-base-metal deposits in the Paleoproterozoic Svecofennian orogenic belts in northern Finland. The objective of this dataset is to serve as a reference tool in heavy indicator minerals-based exploration. By performing correlation analysis with the symmetric pivot coordinates approach for compositional data, as well as principal component analysis, it is demonstrated how all analyzed sulfide species have the capacity to discriminate between Au-only and Au-base-metal deposit types, as well as occurrences of free Au versus refractory Au. Element pairs of symmetric coordinates most suitable for differentiating Au-only systems from Au-base-metal settings are Co/Au and Au/Se in pyrite; Ni/Bi and Se/As in pyrrhotite; and Ni/Ag, Ag/In, Se/Ag, Cr/Ag, Cr/In, Cr/Zn, Zn/Se and Sn/Se in chalcopyrite. Results from principal component analysis reveal that pyrites from Au-base-metal deposits are associated with the positive loadings of Se-As-Co onto PC1 and those from Au-only deposits with negative loadings of Bi-Sb-Te-Au and Ni onto PC1 and PC2, respectively. In the case of pyrrhotite, samples from Au-Co and Au-Cu deposits are clearly distinguished between the positive loadings of Hg-Se-Co onto PC1, and the negative loadings of Sb-Au-Bi-Ni onto PC1. Positive loadings of Ag-Se and Co along PC1 are indicative of chalcopyrite from Au-Co deposits, while negative loadings of Ni and Zn onto PC1 are pointing towards an origin from Au-Cu, as well as Au-only deposits. Additionally, when testing the indicator mineral method with recovered pyrites from till samples from the Peräpohja belt, a potential relationship with bedrock pyrites is successfully demonstrated. This study aims to present the versatility of sulfide trace elements in geochemical exploration, as it could complement the mineral exploration industry with a more efficient and less expensive practice for profitable deposit discovery.

Stream Sediment Indicator Mineral Signatures of the Casino Porphyry Cu-Au-Mo Deposit, Yukon, Canada

Abstract Case studies around porphyry Cu deposits in the glaciated regions of the Canadian Cordillera have identified the indicator mineral signatures of these deposits in till samples and demonstrated that these are useful methods for porphyry Cu exploration. This study applies the same indicator methods to stream sediment samples around the Casino calc-alkaline porphyry Cu-Au-Mo deposit in the unglaciated terrain of west-central Yukon, Canada. It is one of the largest porphyry Cu-Au-Mo deposits in Canada and is hosted in Late Cretaceous quartz monzonite and associated breccias. Bulk (8–16 kg) coarse-grained stream sediment samples were collected in creeks around the deposit, nearby porphyry Cu occurrences and background areas. The Casino deposit has an obvious indicator mineral signature in the <2-mm heavy (>3.2-specific gravity [SG]) and mid-density (2.8- to 3.2-SG) fractions of stream sediments that is detectable at least 18 km downstream and includes gold, chalcopyrite, tourmaline, molybdenite, sphalerite, jarosite, goethite, and pyrite. In contrast, not all of these mineralogically anomalous samples have corresponding anomalous geochemical signatures in the fine fraction. The porphyry indicator minerals identified in this study are similar to those reported for glaciated terrain with the addition of molybdenite and secondary minerals. Indicator mineral methods provide physical evidence of nearby mineralization and can be chemically analyzed to provide insights about the nature of the mineralizing system. Government and exploration surveys could benefit from the addition of indicator mineral methods to routine stream sediment sampling protocols in unglaciated regions of the Yukon and elsewhere globally where porphyry Cu exploration is conducted.

Two different types of provenances and the amalgamation of subduction complexes in the Eastern Tianshan of the Southern Altaids

The nature and final closure of the northern Tianshan Ocean have been debated in regard to the eastern Tianshan orogen, southern Altaids. The Kanguer subduction complex of the eastern Tianshan is the key to addressing these issues. In this study, we report new mapping, geochemical and geochronological results on the Kanguer subduction complex in the Haluo area. Our new results show that upper Permian (257 Ma) basaltic blocks emplaced in a sandstone matrix in the northern HL area are fragments of normal-mid-ocean-ridge-basalt (N-MORB)-type oceanic crust. The geochronological results indicate that the sandstone matrices display two different types of provenances. The first type in the northern part of the cross-section (till Sample YY12) has maximum depositional ages ranging from 316 Ma to 238 Ma. Their depositional settings varied from intraoceanic island arcs to continental Andean arcs after ca. 244 Ma, their detrital zircon age patterns vary from a single peak to multiple peaks, and their zircon εHf(t) values vary from uniquely high positive to some negative values. The second type is in the southern part of the cross-section with Samples YY12 to 21Kg05, which have the geochemical signatures of continental island arc sandstone, multiple-peak detrital zircon-age patterns, and positive to negative zircon εHf(t) values. The youngest sandstone sample has a maximum depositional age of 241 Ma. The above provenance results indicate that all mélanges and coherent units north of Sample YY12 belong to an accretionary complex of the Dananhu intraoceanic arc, and those south of Sample YY12 belong to an accretionary complex of the Yamansu-central Tianshan arc. According to the youngest components in both accretionary complexes, which suggest the latest subduction events, we conclude that the final amalgamation timing was after 238 Ma and that the Paleo-Asian Ocean closed during the Middle to Late Triassic.

Risk factors associated with prediabetes and cardiovascular disease: A perceptive study

Background: Diabetes mellitus is emerging as a major health problem due to its serious complications. It is important to assess the various factors contributing to the occurrence of the diseases so that by limiting these factors the progression of the disease in patients can be controlled. Prediabetes is a state characterized by impaired fasting glucose or impaired glucose tolerance. Aims and Objective: The present study was undertaken to determine the risk factors for Type 2 diabetes mellitus (T2DM) among adults, prediabetic subjects were identified from first degree relatives of T2DMpatients. Materials and Methods: The present observational study was carried out at Department of Physiology, S.P. Medical College and Hospital in collaboration with diabetic research center P.B.M. hospital Bikaner (Rajasthan). Prediabetic subjects were identified from first degree relatives of T2DMpatients, enrolled in diabetic research center P.B.M. hospital Bikaner. Prediabetics (impaired fasting glucose) subjects were identified on the basis of fasting blood glucose 100–125 mg/dL and HbA1C (5.7–6.4%) as per American Diabetic Association (ADA) 2011 guidelines. Consecutive sampling was conducted till sample size satisfied during the period of study. Subjects of age group 20–74 years having FPG between 100 and 125 mg/dL, HbA1C between 5.7% and 6.4%, and gave informed written consent were included in study. Pre-structured performa was used to collect general information, sociodemographic information, baseline physical characteristics, personal habits, biochemical analysis, and for blood parameters. Results: Age, occupation, body mass index (BMI), diet, smoking, alcohol, truncal obesity, and family history of DM were significantly associated with prevalence of T2DM/prediabetes whereas gender and literacy were not. Conclusion: In the present study, it was observed that advanced age, occupational changes, BMI, substance abuse such as alcohol and smoking, truncal obesity, and family history of diabetes were highly associated risk factors for T2DM whereas literacy, gender, and central obesity showed no association with risk of T2DM.

A study to assess the future 10-year cardiovascular and8-year diabetic risk by using Framingham heartscale in prediabetic subjects

Background. Prediabetes is a state characterized by impaired fasting glucose or impaired glucose tolerance. This implies that prediabetes bears an increased risk of cardiovascular complications. Various risk factors are the reason of the progression of cardiovascular diseases and type 2 diabetes mellitus (T2DM) in prediabetics if factors are not overt. Hence, the present study was undertaken to determine the future 10-year cardiovascular and 8-year diabetic risk by using Framingham heart scale in prediabetic subjects. Materials and methods. Present cross-sectional study was carried out at Department of Physiology, S.P. Medical College & Hospital in collaboration with Diabetic Research Centre P.B.M. Hospital Bikaner (Rajasthan). Prediabetic subjects were identified from first-degree relatives of T2DM patients, enrolled in Diabetic Research Centre P.B.M. Hospital Bikaner. Prediabetics (impaired fasting glucose) subjects were identified on the basis of fasting blood glucose of 100 to 125mg/dl and HbA1c (5.7 to 6.4%) as per American Diabetes Association 2011 guidelines. Consecutive sampling was conducted till sample size satisfied during the period of study. Subjects of age group 20–74 years who had fasting blood glucose of 100–125 mg/dl, HbA1c of 5.7 to 6.4% and gave informed written consent were included in study. Pre-structured performa was used to collect general information, sociodemographic information, baseline physical characteristics, personal habits, biochemical analysis, and for blood parameters. Future 10-year cardiovascular and 8-year diabetic risk were assessed by using Framingham heart scale. Results. Age, occupation, body mass index, diet, smoking, alcohol, truncal obesity and family history of diabetes were significantly associated with the prevalence of T2DM/prediabetes whereas gender and literacy were not. Conclusions. In the present study, it was observed that advanced age, occupational changes, body mass index, substance abuse like smoking, central obesity, exercise, blood pressure and family history of diabetes were highly associated with future risk of T2DM and cardiovascular diseases among prediabetic subjects of first-degree relatives.

Risk assessment for non- communicable diseases among adult population of area adopted by urban and rural health care training centre of IGGMC, Nagpur: A cross sectional study

NCDs are leading cause of premature deaths worldwide. Global trends suggest that these diseases to a large extent are associated with life styles like- unhealthy dietary intake, physical inactivity, tobacco use, high alcohol consumption and are on the rise. CBAC (Community Based Assessment Checklist) is a simple means of early identifying risk of NCDs in the community. There is a paucity of published literature using CBAC as screening tool. Hence this community based study was undertaken among adult population of area adopted by urban and rural health care training centre of IGGMC, Nagpur to assess the risk of NCDs and serve as a tool for early diagnosis and treatment.To assess the risk of Non Communicable Diseases using Community Based Assessment Checklist among adult population of area adopted by urban and rural health training centre, IGGMC, Nagpur. To study the risk of NCDs with place of residence and suggest recommendations based on the study findings. A cross sectional community based study was conducted among 376 adults residing in the field practice area of Urban and Rural Health care Training Centre of IGGMC, Nagpur. Data was collected by conducting face to face interview with structured questionnaire which included socio-demographic variable and CBAC questionnaire. Study was conducted from January to May 2022 by using consecutive sampling till sample size was achieved.Overall risk of NCD was found to be 60.9%. The risk of NCD was 61.2% among rural adults while it was 60.6% among urban adults of adopted field practice area of IGGMC, Nagpur. The risk of NCD was found to be significantly associated with Age (p= 0.000), Gender (p=0.000), tobacco use (p=0.000), alcohol consumption (p= 0.000), Waist circumference (p=0.000) and family history of hypertension, Diabetes mellitus and cardiovascular illnesses (p=0.000). There was no significant association found between risk of NCDs and CBAC variables by place of residence except for waist circumference (p = 0.03) Overall most CBAC variables were found to have significant association with NCDs risk however no significant difference was observed between CBAC variables and place of residence.

CT Scanning of Structural Characteristics of Glacial Till in Moxi River Basin, Sichuan Province

Glacial till is a special soil in alpine mountainous areas, which often induces geohazards such as debris flows and landslides due to the influence of special geological environmental conditions in alpine mountainous areas. The change in the structure of glacial till is the main cause of geohazards. Glacial till structure is one of the important factors affecting the mechanical properties of soil. It can explain the mechanical phenomena of soil engineering and establish the quantitative relationship between soil structure and macro–mechanical properties. However, there are few systematic research results on its structure. For this reason, the intact glacial till in the Moxi River Basin, South of Kangding City, Tibetan Autonomous Prefecture of Garzê, Sichuan Province was taken as the research object, and the meso-structure and micro-structure of intact glacial till were studied using CT scanning and scanning electron microscopy (SEM). The meso-structure and micro-structure images of the interior of intact glacial till were obtained and the porosity, particle shape, directivity and structural unit were analyzed. The results show that: (1) the average porosity of longitudinal and transverse sections of intact glacial till are 24.92% and 24.35%, respectively, and the difference is not significant; (2) the average circularity of the particles in the longitudinal and transverse sections is 0.836 and 0.802, respectively, and the average aspect ratio is 2.5 and 3.7, respectively. The shape of the particles in the longitudinal section is more circular than in the transverse section, and the orientation of the particles in the transverse sectional direction is more obvious; (3) the main mineral components of the glacial till sample are mica, feldspar and quartz. In the process of transportation and deposition, the mineral particles undergo different degrees of grinding, crushing and dissolution. The particles are mainly formed by calcareous cementation, and the cementation is dense. The structure is mainly a skeleton structure composed of fine particles that are wrapped or filled. These findings provide the scientific basis for highway-, railway- and hydro-power-station construction and disaster prevention and mitigation in the alpine mountainous area.

Overview of surficial geochemistry and indicator mineral surveys and case studies from the Geological Survey of Canada's GEM Program

The Geological Survey of Canada carried out reconnaissance-scale to deposit-scale geochemical and indicator-mineral surveys and case studies across northern Canada between 2008 and 2020 as part of its Geo-mapping for Energy and Minerals (GEM) program. In these studies, surficial geochemistry was used to determine the concentrations of up to 65 elements in various sample media including lake sediment, lake water, stream sediment, stream water, or till samples across approximately 1 000 000 km 2 of northern Canada. As part of these surficial geochemistry surveys, indicator mineral methods were also used in regional-scale and deposit-scale stream sediment and till surveys. Through this program, areas with anomalous concentrations of elements and/or indicator minerals that are indicative of bedrock mineralization were identified, new mineral exploration models and protocols were developed, a new generation of geoscientists was trained, and geoscience knowledge was transferred to northern communities. Regional- and deposit-scale studies demonstrated how transport data (till geochemistry, indicator mineral abundance) and ice-flow indicator data can be used together to identify and understand complex ice flow and glacial transport. Detailed studies at the Izok Lake Zn–Cu–Pb–Ag VMS, Nunavut, the Pine Point carbonate-hosted Pb–Zn in the Northwest Territories, the Strange Lake REE deposit in Quebec and Labrador as well as U–Cu–Fe–F and Cu–Ag–Au–Au IOCG deposits in the Great Bear magmatic zone, Northwest Territories demonstrate new suites of indicator minerals that can now be used in future reconnaissance- and regional-scale stream sediment and till surveys across Canada.

Suitability of surficial media for Ni–Cu–PGE exploration in an established mining camp: a case study from the South Range of the Sudbury Igneous Complex, Canada

A geochemical study over the southwestern part of the South Range of the Sudbury Igneous Complex was completed to assess the suitability of surficial media (humus, B-horizon soil and C-horizon soil) for delineating geochemical anomalies associated with Ni–Cu–PGE (platinum group element) mineralization. Another objective was to test whether Na pyrophosphate can eliminate the effects of anthropogenic contamination in humus. Results of this study suggest that the natural geochemical signature of humus is strongly overprinted by anthropogenic contamination. Despite no indication of underlying or nearby mineralization, metal concentrations in humus samples by aqua regia collected downwind from smelting operations are higher compared to background, including up to 13 times higher for Pt, 12 times higher for Cu and nine times higher for Ni. The high anthropogenic background masks the geogenic signal such that it is only apparent in humus samples collected in the vicinity of known Ni–Cu–PGE deposits. Results of this study also demonstrate that anthropogenically derived atmospheric fallout also influences the upper B-horizon soil; however, lower B-horizon soil (at >20 cm depth) and C-horizon soil (both developed in till) are not affected. Glacial dispersal from Ni–Cu–PGE mineralization is apparent in C-horizon till samples analysed in this study. Compared to the background concentrations, the unaffected C-horizon till samples collected immediately down-ice of the low-sulfide, high precious metal Vermilion Cu–Ni–PGE deposit are enriched over 20 times in Pt (203 ppb), Au (81 ppm) and Cu (963 ppm), and over 30 times in Ni (1283 ppm). Supplementary material: supplementary tables and figures are available at https://doi.org/10.6084/m9.figshare.c.5691080

A Study on Infant Feeding Practice among Multiparous Postnatal Mothers in Katihar City: A Cross- Sectional Study

Background: India is a land of diverse cultures and traditions. Infant feeding and rearing practices vary across communities, depending on social customs, traditional beliefs, literacy and socio-economic status of the family. These practices at times are not of any benefit to the newborn and can be harmful. Despite its rapid economic growth. Aim & objectives: To study the infant feeding practice in Katihar. Methods: The study was conducted by simple random sampling in Katihar Medical College. All the multiparous women who were in postnatal period were included in the study till sample size was reached. Data was collected after informed consent using pre-tested semi-structured questionnaire and analyzed in SPSS. Results: Out of 100 mothers, 69% of the mothers had initiated breastfeeding within standard norms and 28.5% had given pre-lacteal feeds to their babies which was significantly associated with religion and type of family of the mothers. Majority of the mothers (95.5%) had given colostrum and its association with type of family was significant. Majority of them (80.1%) had breastfed their baby on demand. Breastfeeding technique was proper among only 62.8% of the mothers. Around 86.5% of the mothers had practiced EBF > 6 months and its association with age of the mother, socio-economic status was significant and 78% of the mothers breastfed their child for >18 months. About 85.5% mothers started complementary feeding with CFF. Conclusion: In spite of educational messages by health professionals, certain feeding practices are found unsatisfactory and certain harmful rearing practices are still prevalent in the community. This necessitates additional focus by the policy makers towards maternal and child health to ensure the needs to be fulfilled and to impose certain regulations against prevalent harmful practices in the community.

Concentration-distance from centroids (C-DC) multifractal modeling: A novel approach to characterizing geochemical patterns based on sample distance from mineralization

Various fractal models have been implemented to separate populations and characterize spatial distributions in geochemical data derived from regional mapping programs. This study compares the conventional number-size with a proposed concentration-distance from centroids (C-DC) fractal model to detect geochemically anomalous populations. These models have been applied to centered log-ratio transformed data of VMS-style mineralization related element concentrations in till from a low-density national survey conducted across Sweden. The C-DC model has been applied to the distance between till samples and centroids of geological sub-provinces containing a number of VMS-style deposits, and is derived from the concentration-distance (C-D) approach originally developed using a radial-density (R-D) model. The efficiencies of the models in detecting a multivariate geochemical response to known mineralization are compared using a variant of the overall accuracy matrix. The C-DC model provides accuracy of classification similar to the N-S model. Therefore, Monte Carlo simulation was applied to quantify uncertainties in setting of population thresholds using the two fractal models. It demonstrated greater efficiency of the C-DC model.

Surficial geochemical and mineralogical signatures of Ni-Cu-PGE deposits in glaciated terrain: Examples from the South Range of the Sudbury Igneous Complex, Ontario, Canada

A till geochemistry and indicator mineral (IM) study was carried out in the South Range of the Sudbury Igneous Complex (SIC) to develop surficial mineral exploration techniques that are suitable for low sulfide, high precious metal (LSHPM) and massive sulfide Ni-Cu-PGE mineralization. Surficial exploration in this region is problematic because of heterogeneous till deposits overlain by glaciolacustrine sediments, a naturally high surficial geochemical background, and a paucity of undisturbed till for geochemical sampling due to mining-related operations. The Vermilion and Crean Hill deposits were selected for this case study because their geology and mineralogy have been extensively studied. Pathfinder elements that show a strong, positive (r2 > 0.6, n = 120) correlation with ore elements Ni, Cu, Au and PGEs (Pt, Pd, Ru, Rh, and Ir), which are derived from mineralization and present in elevated concentrations in till samples overlying mineralization are As, Bi, Co, Cr, Pb, Sb and Te. Ore minerals that survive glacial transport and post-glacial weathering and are the best indicators of Ni-Cu-PGE-Au mineralization are grains of gold, chalcopyrite, and sperrylite, predominantly recovered from the < 0.25 mm pan concentrate fraction of till. Despite challenges, this study has identified new exploration targets that warrant further investigation and demonstrates that till geochemistry and IM methods can be used to explore for Ni-Cu-PGE mineralization in established mining camps.