Characterizing Kimberlite Dilution by Crustal Rocks at the Snap Lake Diamond Mine (Northwest Territories, Canada) using SWIR (1.90–2.36 μm) and LWIR (8.1–11.1 μm) Hyperspectral Imagery Collected from Drill Core

Short-wave infrared (SWIR, 1.90–2.36 μm) and long-wave infrared (LWIR, 8.1–11.1 μm) hyperspectral images collected using the SisuROCK system were used to develop an automated methodology for generating kimberlite dilution maps. Smoothed and denoised images from two Snap Lake (Northwest Territories, Canada) kimberlite drill cores were processed, and SWIR and LWIR spectral endmembers were extracted from the images with each mineralogical endmember assigned to one of four compositional groups: undiluted kimberlite, microdiluted kimberlite, micro- and macrodiluted kimberlite, and crustal rocks. These endmembers were used to classify the SWIR and LWIR images, and the results were validated using linescan data, drill core logs, petrology reports, and the results of X-ray diffraction, Raman spectroscopy, and Micro-Fourier Transform Infrared (FTIR) spectroscopy. This study demonstrates that hyperspectral imagery can be used to generate dilution maps for hypabyssal kimberlites that far supersede other current techniques in terms of spatial resolution

FTIR Hyperspectral Imagery: A New Method for Identifying Aragonite, Calcite, and Dolomite in Carbonate Rocks and Assessing their Formational History on the Micron Scale

Hyperspectral imaging combines digital imaging with reflectance spectroscopy, and allows for the in-situ identification of minerals in rock samples in a non-destructive manner. The project presented here focuses on the collection and analysis of hyperspectral images from carbonate rocks for the purpose of developing a technique to identify aragonite, calcite, and dolomite on the micron scale. The information gathered using this technique will serve to better understand the microscopic alterations taking place in minerals throughout diagenesis, and the results are intended to help interpret the paragenetic history of the carbonate rocks. In summary, this presentation will showcase a new analysis method that will aid in the assessment of the quality of carbonate rocks as oil reservoirs. Long-wave infrared (LWIR) hyperspectral images were collected from polished thick sections using a Micro-FTIR instrument with a Focal Plane Array (FPA) detector, which collects hyperspectral images at a pixel size of 2.7 x 2.7 µm. Each hyperspectral image was processed and analyzed to produce a compositional map that shows the location of each mineral and/or the crystallographic orientation of individual mineral grains. Textural analyses were then performed on the compositional maps to extract grain size and textural information. The samples used in this study originated from the Western Canadian Sedimentary Basin and the Austrian Alps, and this work will serve as a foundation for subsequent studies, which will examine the feasibility of using LWIR hyperspectral imagery as an automated drill core logging tool for carbonate rocks

The future of automated drill core logging: Charcaterizating kimberlite dilution by chrustal material at the Snap Lake diamond mine (NT, Canada) using SWIR (1.90-2.36 µm) and LWIR (8.1-11.1 µM) hyperspectral imagery

To develop an automated method for generating predictive crustal dilution maps for kimberlites, short-wave infrared (SWIR, 1.90-2.36 μm) and long-wave infrared (LWIR, 8.1-11.1 μm) hyperspectral images were collected from two drill cores from the Snap Lake diamond mine (NT, Canada) using the SisuROCK system. The images were processed using continuous wavelets to isolate mineral spectral features from the background material. Endmembers were extracted from the images with each mineralogical endmember assigned to one of four compositional groups: undiluted kimberlite, micro-diluted kimberlite, macro- and micro-diluted kimberlite, and crustal rocks. These endmembers were used to classify the SWIR and LWIR images, and the results were validated using linescan data, drill core logs, petrology reports, and the results of X-ray diffraction, Raman spectroscopy, and Micro-FTIR spectroscopy. The classified images were used in three ways: to identify diluted kimberlite, to visualize the contacts between different units, and to visualize the relationship between kimberlite dilution and kimberlite facies. At Snap Lake, the benefits of this technique are twofold: (1) it detects crustal dilution in kimberlite, which can be difficult using only visual linescan techniques, and this will improve diamond grade estimates, and (2)important compositional information can be collected from the surface of drill core in a standardized, automated, rapid, and non-destructive manner. Furthermore, the technique can distinguish between micro- and macro- dilution, which can not be accomplished using visible, conventional drill core logging techniques. Having a predictive dilution map available during the visual drill core logging process results in the production of more detailed drill core logs that help in the collection of dilution data and the development of accurate kimberlite emplacement models

Microbial and chemical contamination of water, sediment and soil in the Nakivubo wetland area in Kampala, Uganda

The reuse of domestic and industrial wastewater in urban settings of the developing world may harm the health of people through direct contact or via contaminated urban agricultural products and drinking water. We assessed chemical and microbial pollutants in 23 sentinel sites along the wastewater and faecal sludge management and reuse chain of Kampala, Uganda. Water samples were examined for bacteria (thermotolerant coliforms (TTCs), Escherichia coli and Salmonella spp.) and helminth eggs. Physico-chemical parameters were determined. Water, sediment and soil samples and edible plants (yams and sugar cane) were tested for heavy metals. Water samples derived from the Nakivubo wetland showed mean concentrations of TTCs of 2.9 × 105colony-forming units (CFU)/100mL. Mean E. coli was 9.9 × 104CFU/100mL. Hookworm eggs were found in 13.5% of the water samples. Mean concentrations of iron (Fe), copper (Cu) and cadmium (Cd) were 21.5, 3.3 and 0.14mg/L, respectively. In soil samples, we found a mean lead (Pb) concentration of 132.7mg/L. In yams, concentrations of Cd, chromium (Cr) and Pb were 4.4, 4.0 and 0.2mg/L, while the respective concentrations in sugar cane were 8.4, 4.3 and 0.2mg/L. TTCs and E. coli in the water, Pb in soil, and Cd, Cr and Pb in the plants were above national thresholds. We conclude that there is considerable environmental pollution in the Nakivubo wetland and the Lake Victoria ecosystem in Kampala. Our findings have important public health implications, and we suggest that a system of sentinel surveillance is being implemented that, in turn, can guide adequate responses

Disease burden due to gastrointestinal pathogens in a wastewater system in Kampala, Uganda

In wastewater systems in Kampala, Uganda, microbial contamination has increased over the past two decades. Those people who live or work along the Nakivubo channel and wetland and those who use the recreational areas along the shores of Lake Victoria are at an elevated risk of gastrointestinal infections. A quantitative microbial risk assessment (QMRA) was applied for five population groups, characterised by different levels of exposure to wastewater in the Nakivubo area, namely: (i) slum dwellers at risk of flooding; (ii) children living in these slum settlements; (iii) workers maintaining the drainage system or managing faecal sludge (sanitation workers); (iv) urban farmers; and (v) swimmers in Lake Victoria. The QMRA was based on measured concentrations of Escherichia coli, Salmonella spp. and Ascaris spp. eggs in wastewater samples. Published ratios between measured organism and pathogenic strains of norovirus, rotavirus, Campylobacter spp., pathogenic E. coli, pathogenic Salmonella spp., Cryptosporidium spp. and Ascaris lumbricoides were used to estimate annual incidence of gastrointestinal illness and the resulting disease burden. The QMRA estimated a total of 59,493 disease episodes per year across all 18,204 exposed people and an annual disease burden of 304.3 disability-adjusted life years (DALYs). Incidence estimates of gastrointestinal disease episodes per year were highest for urban farmers (10.9) and children living in slum communities (8.3), whilst other exposed groups showed lower incidence (<4.3). Disease burden per person per year was highest in urban farmers (0.073 DALYs) followed by sanitation workers (0.040 DALYs) and children in slum communities (0.017 DALYs). Our findings suggest that the exposure to wastewater is associated with public health problems, particularly children and adults living and working along the major wastewater and reuse system in Kampala. Our findings call for specific interventions to reduce the disease burden due to exposure to wastewater.ISSN:2352-352

Microbial and chemical contamination of water, sediment and soil in the Nakivubo wetland area in Kampala, Uganda

The reuse of domestic and industrial wastewater in urban settings of the developing world may harm the health of people through direct contact or via contaminated urban agricultural products and drinking water. We assessed chemical and microbial pollutants in 23 sentinel sites along the wastewater and faecal sludge management and reuse chain of Kampala, Uganda. Water samples were examined for bacteria (thermotolerant coliforms (TTCs), Escherichia coli and Salmonella spp.) and helminth eggs. Physico-chemical parameters were determined. Water, sediment and soil samples and edible plants (yams and sugar cane) were tested for heavy metals. Water samples derived from the Nakivubo wetland showed mean concentrations of TTCs of 2.9 × 10(5) colony-forming units (CFU)/100 mL. Mean E. coli was 9.9 × 10(4) CFU/100 mL. Hookworm eggs were found in 13.5 % of the water samples. Mean concentrations of iron (Fe), copper (Cu) and cadmium (Cd) were 21.5, 3.3 and 0.14 mg/L, respectively. In soil samples, we found a mean lead (Pb) concentration of 132.7 mg/L. In yams, concentrations of Cd, chromium (Cr) and Pb were 4.4, 4.0 and 0.2 mg/L, while the respective concentrations in sugar cane were 8.4, 4.3 and 0.2 mg/L. TTCs and E. coli in the water, Pb in soil, and Cd, Cr and Pb in the plants were above national thresholds. We conclude that there is considerable environmental pollution in the Nakivubo wetland and the Lake Victoria ecosystem in Kampala. Our findings have important public health implications, and we suggest that a system of sentinel surveillance is being implemented that, in turn, can guide adequate responses