The Sino–Zambian Cooperation project provides national catchment sediment geochemical data for 58 elements including Cu and Co from 746 sediment samples at 736 sampling sites, corresponding to a ...sampling density of about 1 site per 1000 km2. The Cu and Co were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) under strict quality control using field duplicates, standard reference materials and analytical replicate samples. The 95% ranges (2.5%–97.5%) of Cu and Co concentrations were from 1.8 to 57.81 × 10−6 and from 0.54 to 22.83 × 10−6, respectively, reflecting locally unevenness distributions. The median values of Cu and Co are 5.77 × 10−6 and 2.98 × 10−6, respectively. The most noticeable anomalous patterns of Cu and Co are distributed between Lusaka and Solwezi (Lufilian Arc Belt) with the trend of increasing concentrations from southeast to northwest. The all spatial distribution patterns of Cu and Co in tectonic units, drainage basins and geomorphological landscapes show good relations with parent rocks, climate, Cu (Co) deposits and smelting plants in Lufilian Arc Belt. The Cu and Co concentrations show metallogenic belts in Mkushi area, between Lusaka and Solwezi areas, and in Livingstone area.
•The 95% range (2.5%–97.5%) of Cu and Co concentrations were from 1.8 to 57.81 × 10-6 and from 0.54 to 22.83 × 10-6, respectively, reflecting locally unevenness distributions.•The median values of Cu and Co are 5.77× 10-6 and 2.98× 10-6, respectively.•Notable Cu and Co enrichments occur in the Lufilian Arc Belt sediment samples.•The overall spatial distribution patterns of Cu and Co in sediment samples show good relations with the climate, Cu (Co) deposits and smelting plants in Lufilian Arc Belt.•The Cu and Co concentrations show metallogenic belts in Mkushi area, between Lusaka and Solwezi areas, and in Livingstone area.
The nation-wide iron ore exploration is primarily based on aeromagnetic survey,based upon which a series of ground follow-up and drilling examination were carried out,and then reconnaissance and ...detailed investigation and exploration were fulfilled.However,for some large.
Spent mushroom substrates can be utilized as organic fertilizer in agricultural production but may pose a health risk. Nitrification inhibitors dicyandiamide and 3,4‐dimethylpyrazole phosphate have ...been used to enhance fertilizer nitrogen utilization efficiency. However, the changes of soil abiotic properties, microbial activities, nitrogen cycling and human‐disease genes, and their comprehensive relationships after the spent mushroom substrate and nitrification inhibitor applications were still unknown. In this study, the spent mushroom substrate and nitrification inhibitor were applied into the agricultural soils at the rates of 2.5% (w/w) and 1.0% of nitrogen content in the spent mushroom substrate, respectively, and then lettuce was planted. Compared with the control, spent mushroom substrate application significantly increased the lettuce biomass, soil enzyme activities and chitinase, protease, nitric‐oxide reductase, nitrogenase, and urease gene abundances. However, the antibiotic resistance and human‐disease gene abundances were also significantly enhanced following the spent mushroom substrate application. Relative to spent mushroom substrate alone, the dicyandiamide application significantly decreased the soil pH and human‐disease gene abundances, although extra dicyandiamide and 3,4‐dimethylpyrazole phosphate enhanced 61.4% and 45.0% of dry biomass of aboveground lettuce. The human‐disease gene abundances were positively correlated with soil pH but were negatively correlated with the Acidobacteria and Streptomyces ratios in soils. Spent mushroom substrate application could generate double‐edged sword effects, and the health risk should be considered in the spent mushroom substrate applications. Extra dicyandiamide application could further promote crop growth while decrease the human‐disease risk from the spent mushroom substrate.
On the basis of the topographical and landscape features in Zimbabwe, an ultra-low density regional geochemical survey was conducted over all of Zimbabwe using stream sediment sampling of catchment ...basins. Sampling methods, elements to be determined and analytical methods for the ultra-low density survey of Zimbabwe are discussed. Regional geochemical maps were compiled based on the sample data and the features of the catchment basins, and the characteristic parameters of the geochemical background throughout Zimbabwe were calculated and are presented. The result of the nationwide geochemical mapping in Zimbabwe was evaluated. A summary of the features of the nationwide ultra-low density geochemical background in Zimbabwe is presented, a preliminary analysis was performed on the distribution of mineral resources and the geochemical provinces in Zimbabwe, and regional prospecting problems are discussed.
•A stream sediment geochemical survey is conducted in Zimbabwe for the first time.•Compilation of geochemical maps for 41 elements.•Revealing distribution feature of mineral resources from geochemical perspective.•Delineation of main geochemical zones (provinces) in Zimbabwe.•Perspective on strategic prospecting in Zimbabwe.
Display omitted
•The age of Muva Supergroup in the Copperbelt Province in Zambia is redeterminated to be greater than or equal to 1966±12Ma.•The ore bodies of Anzan emerald deposit underwent three ...phases of regional metamorphism at 1853±58Ma, 1344±30Ma and 578.3±2.6Ma respectively, and the emerald deposit was eventually formed at 578.3±2.6 Ma.
The Kafubu Emerald Area in Zambia is an important producer of gemstone-quality emeralds. The country rocks include carbonatization altered rock and emerald-hosting biotite chlorite schist from the Anzan emerald deposit in the Kafubu area, Zambia. The technique of LA-MC-ICP-MS is used to perform chronology measurements of the country rock and emerald-hosting rock which belong to Muva Supergroup, yielding zircon U-Pb concordia ages of 1966±12Ma in carbonatization altered rock and 1853±58Ma and 1344±30Ma in biotite chlorite schist. Meanwhile, dating of biotite chlorite schist using the biotite 40Ar–39Ar method has obtained the plateau age of t=578.3±2.6Ma, isochron age of 577.5±3.0Ma and reverse isochron age of 577.4±3.0Ma. Thus, we have redefined the age of Muva Supergroup in the Copperbelt Province in Zambia to be older than or equal to 1966±12Ma, and found that the ore bodies in the Anzan emerald deposit underwent three phases of metamorphism at 1853±58Ma, 1344Ma±30 and 578.3±2.6Ma and finally accomplished the emerald mineralization. The age of the Anzan emerald deposit is earlier than the Kagem (452.1±16Ma) and the Kamakanga emerald deposits (447±8.6Ma).
Stacked targets of natural titanium were impacted with α-particles in the energy range from 4.7 to 26.4 MeV. The excitation functions of the reactions Ti(α,
x)
51Cr and Ti(α,
x)
48Cr were measured. ...The experimental results were compared with some published results and the results of theoretical calculation using the exciton model. The total error of measured cross sections is less than 6%.
Objective： Ethanol treatment induces an increase in oxidative stress. As licorice compounds are potent antioxidants, our aim was to examine whether magnesium isoglycyrrhizinate attenuated lipid ...peroxidation, the major end-point of oxidative damage resulting from ethanol administration. Methods： Four groups（18 animals in each group） of male Kunming mice were used. The first group served as control and received 0.4 ml normal saline daily for 18 days orally. The second group of mice was given 56% ethanol at 16 ml/kg body weight per day for 18 days orally. The third group was given the same dose of ethanol and administrated magnesium isoglycyrrhizinate （15 mg/kg.d, i.p.） for 18 days. The fourth group was given the same dose of ethanol and administrated with magnesium isoglycyrrhizinate （45 mg/kg.d, i.p.） for 18 days. Twenty four hours after 9 days or 18 days of treatment the mice were sacrificed using 10% chloral hydrate. Sperm counts and motility in the epididymis were assessed. The lipid peroxidation and antioxidants of testicular mitochondria were also determined. The pathological changes of testicle tissue of the mice were observed by light microscopy. Results： Magnesium isoglycyrrhizinate effectively prevented the ethanol-induced seminiferous epithelium disorganization and degeneration of Sertoli cells and germ cells. Sperm counts and motility of the magnesium isoglycyrrhizinate treated groups were higher than those of the alcohol treated group, but were lower than those of the control group. The drug exhibited an ability to counteract ethanol induced oxidative challenge as it effectively reduced testicular malondialdehyde （MDA） and increased the activities of superoxide dismutase and glutathione peroxidase. Conclusion： Magnesium isoglycyrrhizinate is able to inhibit the ethanol-induced lipid peroxidation and has a protective effect against testicular oxidative injury.
PDF
