In today’s environment where agriculture needs to produce sustainably, local fertilizer resources must be encouraged to achieve multiple crop performance and environmental goals. The purpose of this study was to inve...In today’s environment where agriculture needs to produce sustainably, local fertilizer resources must be encouraged to achieve multiple crop performance and environmental goals. The purpose of this study was to investigate the effects of combined inputs of biowaste and inorganic fertilisers on the mineralization of carbon and nitrogen of a Lixisol under continuous upland rice growing conditions. To this end, agronomic trials were set up in 2018 and 2019, using a Fisher randomized complete block design with 6 treatments and four replications at Farako-ba research station. The treatments were: T1 (Control), T2 (NPK + Urea), T3 (7500 kgha of Chicken droppings);T4 (7500 kg/ha of chicken droppings + 100 kg/ha of urea);T5 (7500 kg/ha of chicken droppings + 500 kg/ha of Burkina Phosphate);T6 (7500 kg/ha of chicken droppings + 500 kg/ha of Burkina Phosphate + 100 kg/ha of urea). Highest respirometry was observed in treatments T3, T4 and T6 and treatment T4 significantly increased the mineralization coefficient by 15% after 21 days of incubation. T4 and T6 resulted in increases in ammonium ion of 74.15% and 100%, respectively, compared to the control. Likewise, treatments T4 and T6 resulted in a significant increase in nitrate ion of 104.83 and 103.25%, respectively. Biowaste combined with inorganic fertilizers may have a capacity to improve the availability of leachate nutrients under upland rice conditions.展开更多
The subeconomic Mount Novit Zn-Pb-Ag deposit is located approximately 20 km south of Mount Isa,Queensland.In contrast to the nearby Mount Isa,Hilton and George Fisher Zn-Pb-Ag deposits,mineralisation at Mount Novit is...The subeconomic Mount Novit Zn-Pb-Ag deposit is located approximately 20 km south of Mount Isa,Queensland.In contrast to the nearby Mount Isa,Hilton and George Fisher Zn-Pb-Ag deposits,mineralisation at Mount Novit is situated to the west of the regional-scale Mount Isa Fault and is hosted in the Moondarra Siltstone as opposed to the Urquhart Shale.Lower-grade(<4 wt.%Zn+Pb)Zn-Pb-Ag mineralisation primarily replaces pre-existing carbonate alteration and veining and consists of pyrrhotite,pyrite and sphalerite with lesser galena.Higher-grade(>10 wt.%Zn+Pb)mineralisation occurs as a matrix supported breccia dominated by sphalerite and pyrrhotite with galena,pyrite,and magnetite.In-situ U-Pb geochronology was completed on apatite and two textural varieties of monazite.Fine-grained(<50μm)subhedral to anhedral monazite is located within highly foliated biotite alteration directly adjacent Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1527±18 Ma(MSWD=1.06).This age is consistent with the formation of highly foliated biotite alteration during D;deformation of the Isan Orogeny.Apatite from the same fabric yields a lower intercept age of1443±29 Ma(MSWD=1.30).Consistent with previous studies,this age is interpreted to represent the age of a major thrusting event along the Mount Isa Fault that resulted in the cooling of the Mount Novit area below~375℃.Coarse-grained monazite is coeval with Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1457±11 Ma(MSWD=0.28).Sphalerite from Mount Novit has low concentrations(<1 ppm)of Ge and Ga and a relatively high concentration of In(5 to>10 ppm),possibly reflecting the leaching of the metals from an underlying basement unit.The GGIMFis geothermometer(Frenzel et al.,2016)produced a mean formation temperature of 345±52℃.The timing and temperature of Zn-Pb-Ag mineralisation is consistent with the age and cooling temperature of apatite presented in this study.Based on these correlations,we suggest that Zn-Pb-Ag mineralisation at Mount Novit was emplaced during an episode of major thrusting along the Mount Isa Fault,with the precipitation of Zn-Pb-Ag mineralisation driven by the cooling of the Mount Novit area below~375℃.A key implication of this study is a new model for synorogenic Zn-Pb-Ag mineralisation to the south of Mount Isa,which contrasts with the widely accepted regional-scale syngenetic metallogenic model.展开更多
At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allo...At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allows for a more detailed investigation of processes that are normally telescoped to the point of being irresolvable.Very minor platinum-group element(PGE)展开更多
Nitrogen (N) mineralisation contributes considerably to crop growth in fertilized and unfertilized fields. It is useful to be able to assess potential N mineralisation to increase fertilizer application efficiency, pr...Nitrogen (N) mineralisation contributes considerably to crop growth in fertilized and unfertilized fields. It is useful to be able to assess potential N mineralisation to increase fertilizer application efficiency, prevent excessive N runoff, and improve environmental system models. The microbes present in soil mineralize N based on many factors, including soil temperature and moisture, tillage, and levels of organic C and N. The measurement of soil’s ability to mineralize N is considered a good indicator of soil quality. Many methods have been developed to estimate N mineralisation in the laboratory and field. The 7-day anaerobic N mineralisation method developed in the 1960’s is considered reliable and is often used to compare new N-mineralisation testing methods. This study examines the use of soil CO2 evolution as determined using the Solvita Soil Respiration System (Solvita) for estimating N mineralisation by comparing it directly to the anaerobic N mineralisation test. Measured CO2 using Solvita was strongly correlated with anaerobic N mineralisation (r2 = 0.82). Results indicate that the Solvita Soil Respiration System can be used to rapidly assess soil respiration and relative N mineralisation potential in any given soil and is considerably faster and easier to perform in a laboratory setting than the anaerobic N mineralisation test.展开更多
The geology of the Olode area, south-western Nigeria was investigatedpetrographically and geochemically in order to elucidate the mineralisationpotential of the rock units in the area. The area under study is generall...The geology of the Olode area, south-western Nigeria was investigatedpetrographically and geochemically in order to elucidate the mineralisationpotential of the rock units in the area. The area under study is generallychange to underlained by granite gneiss, mica schist and pegmatites.Petrographical studies indicated prevalence of anhedral quartz (30 - 50%),plagioclase (14 - 20%), orthoclase (12 - 15%), muscovite (11 - 15%),tourmaline (6 - 10) and other minerals (8 - 11%) for the pegmatite. Thehigh value of SiO2 and Al2O3 is consistent with the petrographical study.High values and wide range in Ba (34 - 737 ppm) and Zr (3.8 - 132.6 ppm)strongly support a mixture of igneous and sedimentary. The bivariant plotsof Rb vs K/Rb, Zn vs K/Rb and Th vs K/Rb indicated a partial series offractionation, suggesting that the pegmatites are of rare element classeswhile granite gneiss and mica schist belong to the barren muscovite andrare element classes. This was supported by high ratios of K/Cs and K/Babut low Th/U values indicating distinctively low rare metal mineralization.The plot of Na2O/Al2O3 vs K2O/Al2O3 revealed an igneous precursor for allthe rock units. The negative Eu anomalies especially in the pegmatitic rockunit indicates fractionation and point toward a late metasomatic effect andtheir relatively weak negative Ce anomalies, also suggest their rare metalmineralization. The pegmatites, granite gneiss and mica schist of Olodearea considered as barren as all the samples plotted below the Gordiyenkosand Beus’ line of mineralization.展开更多
Fibroblast growth factor 23(FGF23) is a hormone that is mainly secreted by osteocytes and osteoblasts in bone. The critical role of FGF23 in mineral ion homeostasis was first identified in human genetic and acquired r...Fibroblast growth factor 23(FGF23) is a hormone that is mainly secreted by osteocytes and osteoblasts in bone. The critical role of FGF23 in mineral ion homeostasis was first identified in human genetic and acquired rachitic diseases and has been further characterised in animal models. Recent studies have revealed that the levels of FGF23 increase significantly at the very early stages of chronic kidney disease(CKD) and may play a critical role in mineral ion disorders and bone metabolism in these patients. Our recent publications have also shown that FGF23 and its cofactor, Klotho, may play an independent role in directly regulating bone mineralisation instead of producing a systematic effect. In this review, we will discuss the new role of FGF23 in bone mineralisation and the pathophysiology of CKD-related bone disorders.展开更多
The ages of hydrothermal Hg deposits are difficult to constrain because of the lack of suitable minerals for dating.The South China low-temperature metallogenic domain hosts numerous Hg deposits,including the Jianyan ...The ages of hydrothermal Hg deposits are difficult to constrain because of the lack of suitable minerals for dating.The South China low-temperature metallogenic domain hosts numerous Hg deposits,including the Jianyan Hg deposit that is composed mainly of cinnabar and calcite.There are two stages of calcite in the deposit:syn-ore calcite(Cal-Ⅰ)and post-ore/barren calcite(Cal-Ⅱ).Cal-Ⅰis mainly euhedral-subhedral and fine-grained,has homogeneous grey luminescence,and is associated with cinnabar.Subhedral-anhedral Cal-Ⅱcrosscuts Cal-Ⅰand is relatively coarse-grained.The syn-ore Cal-Ⅰhas high U contents(0.1–1.3 ppm)and U/Pb ratios(up to 4.2),and is thus suitable for U-Pb dating.Using a laser ablation-inductively coupled plasma-mass spectrometer equipped with ion counters,we obtained a U-Pb age of 426.3±5.7 Ma(MSWD=1.5)for CalI.This age is interpreted to represent the timing of Hg mineralisation at Jianyan and is similar to ages of 440–400 Ma reported for many carbonate-hosted Pb-Zn and Ba-F deposits in South China.Based on the present results in combination with existing geochemical and geochronological data,we infer that these deposits belong to a Paleozoic Hg-Pb-Zn-Ba-F mineralisation system that was controlled by Caledonian tectonism.展开更多
Constraining the processes of deformation during tectonic switching from compression to extension is difficult because of the scarcity or absence of associated sedimentary and magmatic rocks and weak metamorphism.The ...Constraining the processes of deformation during tectonic switching from compression to extension is difficult because of the scarcity or absence of associated sedimentary and magmatic rocks and weak metamorphism.The east margin of the eastern North China Craton experienced Early to Middle Jurassic compression and Early Cretaceous extension.However,the period of tectonic quiescence lasting~13 million years(between 153 and 140 Ma)during which this transition occurred is poorly understood.This paper reports the identification of small-scale N-S-trending thrust and sinistral strike-slip faults(TSS)and NWtrending thrust and dextral strike-slip faults(TDS)in the Tongyuanpu-Aiyang region,which is part of the northern Liaodong Peninsula.Calculation of the tectonic stress field using striations,fault planes and kinematics reveals a NW-SE-oriented maximum principal axis(σ1),and sub-horizontalσ2 andσ3.Assemblages of N-S-trending TSS and NW-trending TDS were arranged with right stepping and resulted in local uplift and erosion at the junctions between fault terminations,which partitioned the Early and Middle Jurassic basins into residual smaller volcanic-sedimentary basins.These basins were unconformably overlain by small Early Cretaceous volcanic-sedimentary basins,such as those at Tongyuanpu and Fangjiaweizi.Magmatic ages and the timing of basin formation constrain the initiation of tectonic switching to 156–153 Ma,and its termination to 140–139 Ma.We suggest that R-R’Riedel shears controlled the formation of the N-S-trending TSS and NW-trending TDS.The R-R’shears were produced by continued sinistral strike-slip and northward growth along the Bohai Bay segment of the Tan-Lu fault zone during the Late Jurassic to early Early Cretaceous,simultaneous with a gradual weakening in the tectonic stress field during a switch in the direction of subduction of the Palaeo-Pacific plate from NW-ward to NNW-ward.This tectonic switching might have promoted the dissolution of gold and migration of gold-bearing fluids.展开更多
Late Mesozoic igneous intrusions and extensional structures in Carboniferous to Permian sequences in the SW Fujian region acted as important controls on the localisation of Fe-polymetallic de-posits.Here we document t...Late Mesozoic igneous intrusions and extensional structures in Carboniferous to Permian sequences in the SW Fujian region acted as important controls on the localisation of Fe-polymetallic de-posits.Here we document the identification of extensional deformation at shallow crustal levels and syn-tectonic granites related to normal faults.Based on spatial distribution and structural features,the extensional deformation can be divided into cover-only and basement-intersecting styles.A series of syn-tectonic plutons were emplaced into the footwall of normal faults.Representative samples of the Tangquan Granite have high SiO2(66.4 wt.%-73.9 wt.%)assays and Mg#values(37-59).The samples also have relatively homogenous initial 87Sr/86Sr(0.7083-0.7089)andεNd(-9.2--10.2)values.Geochemical and isotopic evidences indicate that the Tangquan granite originates from a hybrid source including lower crustal-derived felsic and lithospheric mantle-derived mafic magmas.Zircon U-Pb dating indicates that the granodiorite phase from the pluton crystallised at 161±4 Ma and the monzogranite phase crystallised at 159±1 Ma.Combined with the granitic rocks in a wider region of SE China,the widespread granitic magmatism and polymetallic mineralisation have been synchronous during the Late Mesozoic,probably resulting from extensional tectonics related to the lithospheric thinning.展开更多
Conophyton(Maslov)is a cylindroidal stromatolite form-genus characterized by nested conical laminae.Well-preserved Conophyton,up to 4 m tall and with basal diameters of up to 50 cm,are exposed in the Proterozoic Atar ...Conophyton(Maslov)is a cylindroidal stromatolite form-genus characterized by nested conical laminae.Well-preserved Conophyton,up to 4 m tall and with basal diameters of up to 50 cm,are exposed in the Proterozoic Atar Formation of Mauritania,where many occur together,in growth position,as fields of individual columns spaced between 5 and 70 cm apart.The uniformity of these forms and their regular distribution suggest that they grew in quiet-water environments below wave base.Evidence for their penecontemporaneous organomineralization is indicated by nearby toppled examples of undeformed Conophyton forms alongside eroded lithified Conophyton fragments in carbonate breccias.Two characteristics of Conophyton have been used to classify the structures-the form of the lamination and the nature of its axial structure.A mathematical/physical model provides an explanation for the growth pattern of Conophyton.It predicts that coniform structures with thickened axial zones form when upward organic growth of a biofilm moderately exceeds the rate of its mineralization.The varying characteristics of these features between different forms of Conophyton are thought to reflect biomineralization of the decaying biofilm rather than differences in the composition of microbial communities.A modern example of a syngenetic mineralization process capable of producing similar structures has been observed in the contemporary sediments of Lake Preston,Western Australia,where benthic microbial mats are being transformed into coniform lithified crusts.The initial biomineralization of the coniform mat forms magnesium silicate that first coats and permineralizes web-like microbial extracellular polymeric substances(EPS)and then coalesces into a uniform mass that provides mechanical strength to the cones.At a later stage,massive carbonate crystal growth occurs that over-prints much of this texture,leaving only small,remnant areas of the magnesium silicate phase.Many fossil Conophyton are composed of dolomite,and the remains of the microbial communities responsible for their construction are rarely found,except in areas of chert within the Conophyton.It is suggested that Proterozoic Conophyton were constructed in a tranquil environment through the accretion of microbial mats that were syngenetically permineralized by a magnesium silicate such as a smectite.Later,much of the unstable smectite would be susceptible to diagenetic replacement by either dolomite,or chert in which remnants of microbes that had been coated or permineralized could,potentially,be preserved.展开更多
The objective of this study was to examine the influence of meat-and-bone meal(MBM) and phytase inclusion on growth performance, bone mineralisation and apparent digestibility coefficients of nutrients in broiler chic...The objective of this study was to examine the influence of meat-and-bone meal(MBM) and phytase inclusion on growth performance, bone mineralisation and apparent digestibility coefficients of nutrients in broiler chickens offered wheat-based diets. The feeding study comprised 7 dietary treatments: positive control(PC, 9.0% Ca and 4.5% available phosphorous [AvP] in starter, 7.0% Ca and 3.5% AvP in finisher); negative control(NC, 7.2% Ca and 3.0% AvP in starter, 5.2% Ca and 2.0% AvP in finisher) diets incorporating a 3 × 2 factorial array of 3 MBM inclusions(0, 60, 120 g/kg) and 2 levels of phytase supplementation(0 and 1,000 FYT/kg). Each treatment was allocated to 6 replicated pens with 30 birds per pen in an environmentally-controlled deep litter facility. A total of 1,260 one-day-old male Ross 308 chicks were offered starter diets from 1 to 14 days post-hatch and finisher diets from 15 to 36 days posthatch. There were significant(P < 0.05) interactions between MBM inclusions and phytase supplementation on weight gain and feed intake in starter diets. Phytase significantly increased weight gain in diets without MBM and did not influence weight gain in diets with 60 and 120 g/kg MBM. Collectively,increasing MBM inclusion significantly reduced weight gain in starter diets(P < 0.0001). There were dietary interactions(P < 0.01) on toe ash where phytase significantly improved toe ash in diet without MBM and did not influence toe ash in the other two groups of negative control diets. There were no dietary treatment interactions on apparent ileal digestibility coefficients of starch and protein except that diets without MBM had significantly(P < 0.01) lower ileal starch digestibility and diets with 120 g/kg MBM had significantly(P < 0.0001) lower ileal protein digestibility. No dietary influence on ileal fat digestibility was observed. There were dietary interactions on ileal digestibilities of isoleucine, valine and glycine. Phytase significantly increased glycine digestibility in diets with 60 and 120 g/kg MBM but not in diets without MBM, Including 120 g/kg MBM significantly(P < 0.01) depressed apparent digestibility coefficients of 13 ex 16 amino acids in the distal ileum. This study demonstrated the negative impacts of MBM on amino acid digestibility and growth performance. Also, responses to phytase were more pronounced in diets without MBM, which may have been due to their relatively lower available P and higher phytate concentrations in comparison to diets containing MBM.展开更多
This work describes in detail the experimental investigation of the physico-mechanical properties of nonstructural hemp concrete(usually used as insulating wall material)when the Air-lime based Tradial PF70 binder is ...This work describes in detail the experimental investigation of the physico-mechanical properties of nonstructural hemp concrete(usually used as insulating wall material)when the Air-lime based Tradial PF70 binder is partially replaced using Metakaolin.The objective is to reduce the amount of free Ca2+ions in the binder as these are responsible for the degradation of vegetables particles and can therefore induce a loss of mechanical performances.In order to assess the effectiveness of pozzolanic reaction,amounts of 0%,10%,and 20%vol.of Air-lime binder were replaced by the Metakaolin material,while testing the mechanical properties of concrete specimens containing 200%and 300%of hemp particles.Through SEM and EDX analysis,a tight relationship has been found to exist between the Metakaolin content and physical-mechanical properties of specimen.The pozzolanic reaction consumes calcium hydroxide from binder to produce Hydrated Calcium Silicates(C-S-H)and in turn,this leads to a decrease in the pH-value of the pore solution which is the main factor responsible for hemp particle degradation.展开更多
文摘In today’s environment where agriculture needs to produce sustainably, local fertilizer resources must be encouraged to achieve multiple crop performance and environmental goals. The purpose of this study was to investigate the effects of combined inputs of biowaste and inorganic fertilisers on the mineralization of carbon and nitrogen of a Lixisol under continuous upland rice growing conditions. To this end, agronomic trials were set up in 2018 and 2019, using a Fisher randomized complete block design with 6 treatments and four replications at Farako-ba research station. The treatments were: T1 (Control), T2 (NPK + Urea), T3 (7500 kgha of Chicken droppings);T4 (7500 kg/ha of chicken droppings + 100 kg/ha of urea);T5 (7500 kg/ha of chicken droppings + 500 kg/ha of Burkina Phosphate);T6 (7500 kg/ha of chicken droppings + 500 kg/ha of Burkina Phosphate + 100 kg/ha of urea). Highest respirometry was observed in treatments T3, T4 and T6 and treatment T4 significantly increased the mineralization coefficient by 15% after 21 days of incubation. T4 and T6 resulted in increases in ammonium ion of 74.15% and 100%, respectively, compared to the control. Likewise, treatments T4 and T6 resulted in a significant increase in nitrate ion of 104.83 and 103.25%, respectively. Biowaste combined with inorganic fertilizers may have a capacity to improve the availability of leachate nutrients under upland rice conditions.
基金supported by the Australian Government Research Training Programfunded by Mount Isa MinesDa Glencore Company and forms part of the Mount Isa Research for Geology and Exploration(MIRGE)project。
文摘The subeconomic Mount Novit Zn-Pb-Ag deposit is located approximately 20 km south of Mount Isa,Queensland.In contrast to the nearby Mount Isa,Hilton and George Fisher Zn-Pb-Ag deposits,mineralisation at Mount Novit is situated to the west of the regional-scale Mount Isa Fault and is hosted in the Moondarra Siltstone as opposed to the Urquhart Shale.Lower-grade(<4 wt.%Zn+Pb)Zn-Pb-Ag mineralisation primarily replaces pre-existing carbonate alteration and veining and consists of pyrrhotite,pyrite and sphalerite with lesser galena.Higher-grade(>10 wt.%Zn+Pb)mineralisation occurs as a matrix supported breccia dominated by sphalerite and pyrrhotite with galena,pyrite,and magnetite.In-situ U-Pb geochronology was completed on apatite and two textural varieties of monazite.Fine-grained(<50μm)subhedral to anhedral monazite is located within highly foliated biotite alteration directly adjacent Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1527±18 Ma(MSWD=1.06).This age is consistent with the formation of highly foliated biotite alteration during D;deformation of the Isan Orogeny.Apatite from the same fabric yields a lower intercept age of1443±29 Ma(MSWD=1.30).Consistent with previous studies,this age is interpreted to represent the age of a major thrusting event along the Mount Isa Fault that resulted in the cooling of the Mount Novit area below~375℃.Coarse-grained monazite is coeval with Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1457±11 Ma(MSWD=0.28).Sphalerite from Mount Novit has low concentrations(<1 ppm)of Ge and Ga and a relatively high concentration of In(5 to>10 ppm),possibly reflecting the leaching of the metals from an underlying basement unit.The GGIMFis geothermometer(Frenzel et al.,2016)produced a mean formation temperature of 345±52℃.The timing and temperature of Zn-Pb-Ag mineralisation is consistent with the age and cooling temperature of apatite presented in this study.Based on these correlations,we suggest that Zn-Pb-Ag mineralisation at Mount Novit was emplaced during an episode of major thrusting along the Mount Isa Fault,with the precipitation of Zn-Pb-Ag mineralisation driven by the cooling of the Mount Novit area below~375℃.A key implication of this study is a new model for synorogenic Zn-Pb-Ag mineralisation to the south of Mount Isa,which contrasts with the widely accepted regional-scale syngenetic metallogenic model.
文摘At Eastern Platinum Mine in the western Bushveld Complex,the entire Merensky Pyroxenite Unit reaches up to 11 m in thickness,in contrast to many sections where it is only 1-3 m thick.This greatly expanded section allows for a more detailed investigation of processes that are normally telescoped to the point of being irresolvable.Very minor platinum-group element(PGE)
文摘Nitrogen (N) mineralisation contributes considerably to crop growth in fertilized and unfertilized fields. It is useful to be able to assess potential N mineralisation to increase fertilizer application efficiency, prevent excessive N runoff, and improve environmental system models. The microbes present in soil mineralize N based on many factors, including soil temperature and moisture, tillage, and levels of organic C and N. The measurement of soil’s ability to mineralize N is considered a good indicator of soil quality. Many methods have been developed to estimate N mineralisation in the laboratory and field. The 7-day anaerobic N mineralisation method developed in the 1960’s is considered reliable and is often used to compare new N-mineralisation testing methods. This study examines the use of soil CO2 evolution as determined using the Solvita Soil Respiration System (Solvita) for estimating N mineralisation by comparing it directly to the anaerobic N mineralisation test. Measured CO2 using Solvita was strongly correlated with anaerobic N mineralisation (r2 = 0.82). Results indicate that the Solvita Soil Respiration System can be used to rapidly assess soil respiration and relative N mineralisation potential in any given soil and is considerably faster and easier to perform in a laboratory setting than the anaerobic N mineralisation test.
文摘The geology of the Olode area, south-western Nigeria was investigatedpetrographically and geochemically in order to elucidate the mineralisationpotential of the rock units in the area. The area under study is generallychange to underlained by granite gneiss, mica schist and pegmatites.Petrographical studies indicated prevalence of anhedral quartz (30 - 50%),plagioclase (14 - 20%), orthoclase (12 - 15%), muscovite (11 - 15%),tourmaline (6 - 10) and other minerals (8 - 11%) for the pegmatite. Thehigh value of SiO2 and Al2O3 is consistent with the petrographical study.High values and wide range in Ba (34 - 737 ppm) and Zr (3.8 - 132.6 ppm)strongly support a mixture of igneous and sedimentary. The bivariant plotsof Rb vs K/Rb, Zn vs K/Rb and Th vs K/Rb indicated a partial series offractionation, suggesting that the pegmatites are of rare element classeswhile granite gneiss and mica schist belong to the barren muscovite andrare element classes. This was supported by high ratios of K/Cs and K/Babut low Th/U values indicating distinctively low rare metal mineralization.The plot of Na2O/Al2O3 vs K2O/Al2O3 revealed an igneous precursor for allthe rock units. The negative Eu anomalies especially in the pegmatitic rockunit indicates fractionation and point toward a late metasomatic effect andtheir relatively weak negative Ce anomalies, also suggest their rare metalmineralization. The pegmatites, granite gneiss and mica schist of Olodearea considered as barren as all the samples plotted below the Gordiyenkosand Beus’ line of mineralization.
基金supported by the National Natural Science Foundation of China (81371173)the Program for New Century Excellent Talents in University (NCET-12-0379)+1 种基金Sichuan Provincial Government Grant (2013JQ0017)supported by Open Fund of State Key Laboratory of Oral Diseases, Sichuan University
文摘Fibroblast growth factor 23(FGF23) is a hormone that is mainly secreted by osteocytes and osteoblasts in bone. The critical role of FGF23 in mineral ion homeostasis was first identified in human genetic and acquired rachitic diseases and has been further characterised in animal models. Recent studies have revealed that the levels of FGF23 increase significantly at the very early stages of chronic kidney disease(CKD) and may play a critical role in mineral ion disorders and bone metabolism in these patients. Our recent publications have also shown that FGF23 and its cofactor, Klotho, may play an independent role in directly regulating bone mineralisation instead of producing a systematic effect. In this review, we will discuss the new role of FGF23 in bone mineralisation and the pathophysiology of CKD-related bone disorders.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41872095,U1812402,and 42172082)the Research Startup Project of Yunnan University(Grant No.YJRC4201804)the Talents Program Project of Yunnan Province(Grant No.YNQR-QNRC-2018-104)to Jiaxi ZHOU。
文摘The ages of hydrothermal Hg deposits are difficult to constrain because of the lack of suitable minerals for dating.The South China low-temperature metallogenic domain hosts numerous Hg deposits,including the Jianyan Hg deposit that is composed mainly of cinnabar and calcite.There are two stages of calcite in the deposit:syn-ore calcite(Cal-Ⅰ)and post-ore/barren calcite(Cal-Ⅱ).Cal-Ⅰis mainly euhedral-subhedral and fine-grained,has homogeneous grey luminescence,and is associated with cinnabar.Subhedral-anhedral Cal-Ⅱcrosscuts Cal-Ⅰand is relatively coarse-grained.The syn-ore Cal-Ⅰhas high U contents(0.1–1.3 ppm)and U/Pb ratios(up to 4.2),and is thus suitable for U-Pb dating.Using a laser ablation-inductively coupled plasma-mass spectrometer equipped with ion counters,we obtained a U-Pb age of 426.3±5.7 Ma(MSWD=1.5)for CalI.This age is interpreted to represent the timing of Hg mineralisation at Jianyan and is similar to ages of 440–400 Ma reported for many carbonate-hosted Pb-Zn and Ba-F deposits in South China.Based on the present results in combination with existing geochemical and geochronological data,we infer that these deposits belong to a Paleozoic Hg-Pb-Zn-Ba-F mineralisation system that was controlled by Caledonian tectonism.
基金supported by the National Key R&D Program of China(Grant No.2016YFC0600102)the National Natural Science Foundation of China(Grant No.42030306)the 111 Project of the Ministry of Science and Technology,China(Grant No.BP0719021)。
文摘Constraining the processes of deformation during tectonic switching from compression to extension is difficult because of the scarcity or absence of associated sedimentary and magmatic rocks and weak metamorphism.The east margin of the eastern North China Craton experienced Early to Middle Jurassic compression and Early Cretaceous extension.However,the period of tectonic quiescence lasting~13 million years(between 153 and 140 Ma)during which this transition occurred is poorly understood.This paper reports the identification of small-scale N-S-trending thrust and sinistral strike-slip faults(TSS)and NWtrending thrust and dextral strike-slip faults(TDS)in the Tongyuanpu-Aiyang region,which is part of the northern Liaodong Peninsula.Calculation of the tectonic stress field using striations,fault planes and kinematics reveals a NW-SE-oriented maximum principal axis(σ1),and sub-horizontalσ2 andσ3.Assemblages of N-S-trending TSS and NW-trending TDS were arranged with right stepping and resulted in local uplift and erosion at the junctions between fault terminations,which partitioned the Early and Middle Jurassic basins into residual smaller volcanic-sedimentary basins.These basins were unconformably overlain by small Early Cretaceous volcanic-sedimentary basins,such as those at Tongyuanpu and Fangjiaweizi.Magmatic ages and the timing of basin formation constrain the initiation of tectonic switching to 156–153 Ma,and its termination to 140–139 Ma.We suggest that R-R’Riedel shears controlled the formation of the N-S-trending TSS and NW-trending TDS.The R-R’shears were produced by continued sinistral strike-slip and northward growth along the Bohai Bay segment of the Tan-Lu fault zone during the Late Jurassic to early Early Cretaceous,simultaneous with a gradual weakening in the tectonic stress field during a switch in the direction of subduction of the Palaeo-Pacific plate from NW-ward to NNW-ward.This tectonic switching might have promoted the dissolution of gold and migration of gold-bearing fluids.
基金This study is financially supported by the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0804)Major Research Plan of the National Natural Science Foundation of China(No.91755215)+5 种基金National Natural Science Foundation of China(No.41703037)the National Key R&D Plan(No.2018YFC0603801)the Open Research Pro-ject from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing(No.GPMR201816)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Nos.KK1914,KK2013)the Chinese Geological Survey Program(Nos.DD20201173,DD20190379)Key Laboratory of Regional Geology and Mineralization,Hebei GEO University(No.HGU-RGMKF192).
文摘Late Mesozoic igneous intrusions and extensional structures in Carboniferous to Permian sequences in the SW Fujian region acted as important controls on the localisation of Fe-polymetallic de-posits.Here we document the identification of extensional deformation at shallow crustal levels and syn-tectonic granites related to normal faults.Based on spatial distribution and structural features,the extensional deformation can be divided into cover-only and basement-intersecting styles.A series of syn-tectonic plutons were emplaced into the footwall of normal faults.Representative samples of the Tangquan Granite have high SiO2(66.4 wt.%-73.9 wt.%)assays and Mg#values(37-59).The samples also have relatively homogenous initial 87Sr/86Sr(0.7083-0.7089)andεNd(-9.2--10.2)values.Geochemical and isotopic evidences indicate that the Tangquan granite originates from a hybrid source including lower crustal-derived felsic and lithospheric mantle-derived mafic magmas.Zircon U-Pb dating indicates that the granodiorite phase from the pluton crystallised at 161±4 Ma and the monzogranite phase crystallised at 159±1 Ma.Combined with the granitic rocks in a wider region of SE China,the widespread granitic magmatism and polymetallic mineralisation have been synchronous during the Late Mesozoic,probably resulting from extensional tectonics related to the lithospheric thinning.
文摘Conophyton(Maslov)is a cylindroidal stromatolite form-genus characterized by nested conical laminae.Well-preserved Conophyton,up to 4 m tall and with basal diameters of up to 50 cm,are exposed in the Proterozoic Atar Formation of Mauritania,where many occur together,in growth position,as fields of individual columns spaced between 5 and 70 cm apart.The uniformity of these forms and their regular distribution suggest that they grew in quiet-water environments below wave base.Evidence for their penecontemporaneous organomineralization is indicated by nearby toppled examples of undeformed Conophyton forms alongside eroded lithified Conophyton fragments in carbonate breccias.Two characteristics of Conophyton have been used to classify the structures-the form of the lamination and the nature of its axial structure.A mathematical/physical model provides an explanation for the growth pattern of Conophyton.It predicts that coniform structures with thickened axial zones form when upward organic growth of a biofilm moderately exceeds the rate of its mineralization.The varying characteristics of these features between different forms of Conophyton are thought to reflect biomineralization of the decaying biofilm rather than differences in the composition of microbial communities.A modern example of a syngenetic mineralization process capable of producing similar structures has been observed in the contemporary sediments of Lake Preston,Western Australia,where benthic microbial mats are being transformed into coniform lithified crusts.The initial biomineralization of the coniform mat forms magnesium silicate that first coats and permineralizes web-like microbial extracellular polymeric substances(EPS)and then coalesces into a uniform mass that provides mechanical strength to the cones.At a later stage,massive carbonate crystal growth occurs that over-prints much of this texture,leaving only small,remnant areas of the magnesium silicate phase.Many fossil Conophyton are composed of dolomite,and the remains of the microbial communities responsible for their construction are rarely found,except in areas of chert within the Conophyton.It is suggested that Proterozoic Conophyton were constructed in a tranquil environment through the accretion of microbial mats that were syngenetically permineralized by a magnesium silicate such as a smectite.Later,much of the unstable smectite would be susceptible to diagenetic replacement by either dolomite,or chert in which remnants of microbes that had been coated or permineralized could,potentially,be preserved.
文摘The objective of this study was to examine the influence of meat-and-bone meal(MBM) and phytase inclusion on growth performance, bone mineralisation and apparent digestibility coefficients of nutrients in broiler chickens offered wheat-based diets. The feeding study comprised 7 dietary treatments: positive control(PC, 9.0% Ca and 4.5% available phosphorous [AvP] in starter, 7.0% Ca and 3.5% AvP in finisher); negative control(NC, 7.2% Ca and 3.0% AvP in starter, 5.2% Ca and 2.0% AvP in finisher) diets incorporating a 3 × 2 factorial array of 3 MBM inclusions(0, 60, 120 g/kg) and 2 levels of phytase supplementation(0 and 1,000 FYT/kg). Each treatment was allocated to 6 replicated pens with 30 birds per pen in an environmentally-controlled deep litter facility. A total of 1,260 one-day-old male Ross 308 chicks were offered starter diets from 1 to 14 days post-hatch and finisher diets from 15 to 36 days posthatch. There were significant(P < 0.05) interactions between MBM inclusions and phytase supplementation on weight gain and feed intake in starter diets. Phytase significantly increased weight gain in diets without MBM and did not influence weight gain in diets with 60 and 120 g/kg MBM. Collectively,increasing MBM inclusion significantly reduced weight gain in starter diets(P < 0.0001). There were dietary interactions(P < 0.01) on toe ash where phytase significantly improved toe ash in diet without MBM and did not influence toe ash in the other two groups of negative control diets. There were no dietary treatment interactions on apparent ileal digestibility coefficients of starch and protein except that diets without MBM had significantly(P < 0.01) lower ileal starch digestibility and diets with 120 g/kg MBM had significantly(P < 0.0001) lower ileal protein digestibility. No dietary influence on ileal fat digestibility was observed. There were dietary interactions on ileal digestibilities of isoleucine, valine and glycine. Phytase significantly increased glycine digestibility in diets with 60 and 120 g/kg MBM but not in diets without MBM, Including 120 g/kg MBM significantly(P < 0.01) depressed apparent digestibility coefficients of 13 ex 16 amino acids in the distal ileum. This study demonstrated the negative impacts of MBM on amino acid digestibility and growth performance. Also, responses to phytase were more pronounced in diets without MBM, which may have been due to their relatively lower available P and higher phytate concentrations in comparison to diets containing MBM.
文摘This work describes in detail the experimental investigation of the physico-mechanical properties of nonstructural hemp concrete(usually used as insulating wall material)when the Air-lime based Tradial PF70 binder is partially replaced using Metakaolin.The objective is to reduce the amount of free Ca2+ions in the binder as these are responsible for the degradation of vegetables particles and can therefore induce a loss of mechanical performances.In order to assess the effectiveness of pozzolanic reaction,amounts of 0%,10%,and 20%vol.of Air-lime binder were replaced by the Metakaolin material,while testing the mechanical properties of concrete specimens containing 200%and 300%of hemp particles.Through SEM and EDX analysis,a tight relationship has been found to exist between the Metakaolin content and physical-mechanical properties of specimen.The pozzolanic reaction consumes calcium hydroxide from binder to produce Hydrated Calcium Silicates(C-S-H)and in turn,this leads to a decrease in the pH-value of the pore solution which is the main factor responsible for hemp particle degradation.
