The Zhob ophiolite comprises the Naweoba, Omzha and Ali Khanzai blocks, which are surrounded by the sediments of the Alozai Group and Loralai Formation. The Ali Khanzai Block contains metamorphic, ultramafic, gabbroic...The Zhob ophiolite comprises the Naweoba, Omzha and Ali Khanzai blocks, which are surrounded by the sediments of the Alozai Group and Loralai Formation. The Ali Khanzai Block contains metamorphic, ultramafic, gabbroic, volcanic and volcaniclastic rocks with associated chert. The Zhob manganese deposits found in the Ali Khanzai Block, occur in banded, lenticular and massive forms within red to brown coloured metachert. Braunite and pyrolusite are the main constituent manganese-bearing minerals with minor hausmannite, hematite and barite while quartz is the major gangue mineral with some carbonate minerals. Geochemical evidence from the major oxides indicates that the manganese mineralization and associated metachert at Zhob were formed by hydrothermal activity with little contribution from contemporaneous volcanic materials and this is confirmed by high Fe/Mn and low Co/Zn ratios and trace element patterns. These deposits formed along with seafloor spreading centres and were later obducted as part of Ali Khanzai Block of Zhob ophiolite.展开更多
Zhob valley ophiolite comprises Khanozai,Muslim Bagh,and Zhob chromitite occurrences located in Pakistan.These occurrences occur in massive,disseminated and nodular which exhibit both magmatic and deformational textur...Zhob valley ophiolite comprises Khanozai,Muslim Bagh,and Zhob chromitite occurrences located in Pakistan.These occurrences occur in massive,disseminated and nodular which exhibit both magmatic and deformational texture.The Muslim Bagh and Khanozai chromitites are classified into high-Cr chromitite(Cr#=0.66-0.85)while Zhob chromitite falls into high-Al chromitite(Cr#=0.53-0.58)composition.展开更多
The use of inorganic nitrogen(N)fertilizers has increased drastically to meet the food requirements of the world’s growing population.However,the excessive use of chemical nitrogen fertilizer has caused a series of s...The use of inorganic nitrogen(N)fertilizers has increased drastically to meet the food requirements of the world’s growing population.However,the excessive use of chemical nitrogen fertilizer has caused a series of soil and environmental problems,such as soil hardening,lower nitrogen use efficiency(NUE),nitrate pollution of water sources,nitrous oxide emissions,etc.In this review,we aimed to elaborate and discuss the role of engineered biochar in inducing the stability of water-stable macroaggregates,improving inorganic N transformation,and utilization efficiency to address the current uncertainties of nitrogen loss and maintaining soil and water quality.Firstly,we elucidated the characteristics of engineered biochar in improving biochar quality to work as a multifunctional player in the ecosystem and promote resource utilization,soil conservation,and ecosystem preservation.Secondly,we discussed how the engineered biochar modulates the stability of water-stable macroaggregates and soil inorganic nitrogen transformation to enhance plant response under various toxic or deficient nitrogen conditions in the soil.Thirdly,the role of engineered biochar in biological nitrogen fixation,mediating nirK,nirS,and nosZ genes to promote the conversion of N_(2)O to N_(2),and decreasing denitrification and N_(2)O emission was reviewed.Altogether,we suggest that engineered biochar amendment to soil can regulate soil water-stable macroaggregates,reduce N input,improve nitrogen metabolism,and finally,NUE and crop growth.To the best of our knowledge,this is the first time to evaluate the combined interactions of"engineered biochar×soil×NUE×crop growth,"providing advantages over the increasing N and water utilization and crop productivity separately with the aim of enhancing the stability of water-stable macroaggregates and NUE together on a sustainable basis.展开更多
基金the six months,HRD Foreign scholarships of the Centre of Excellence in Mineralogy,University of Balochistan,Quetta,which was approved by the Higher Education Commission,Pakistan under its PSDP development project“Capacity Building and Strengthening of the Centre of Excellence in Mineralogy”partly supported by the Higher Education Commission,Pakistan“National Research Program for Universities(NRPU)Project#3593”to Muhammad Ishaq Kakar。
文摘The Zhob ophiolite comprises the Naweoba, Omzha and Ali Khanzai blocks, which are surrounded by the sediments of the Alozai Group and Loralai Formation. The Ali Khanzai Block contains metamorphic, ultramafic, gabbroic, volcanic and volcaniclastic rocks with associated chert. The Zhob manganese deposits found in the Ali Khanzai Block, occur in banded, lenticular and massive forms within red to brown coloured metachert. Braunite and pyrolusite are the main constituent manganese-bearing minerals with minor hausmannite, hematite and barite while quartz is the major gangue mineral with some carbonate minerals. Geochemical evidence from the major oxides indicates that the manganese mineralization and associated metachert at Zhob were formed by hydrothermal activity with little contribution from contemporaneous volcanic materials and this is confirmed by high Fe/Mn and low Co/Zn ratios and trace element patterns. These deposits formed along with seafloor spreading centres and were later obducted as part of Ali Khanzai Block of Zhob ophiolite.
基金financially supported by the six months,HRD Foreign scholarships of the Centre of Excellence in Mineralogy,University of Baluchistan,Quetta,which was approved by the Higher Education Commission,Pakistan under its PSDP development project“Capacity Building and Strengthening of the Centre of Excellence in Mineralogy”.The research was also partly supported by Higher Education Commission,Pakistan“National Research Program for Universities(NRPU)Project#3593”to M.Ishaq Kakar.The authors are grateful to Editor-in-Chief and reviewers for their constructive comments which improved the manuscript.
文摘Zhob valley ophiolite comprises Khanozai,Muslim Bagh,and Zhob chromitite occurrences located in Pakistan.These occurrences occur in massive,disseminated and nodular which exhibit both magmatic and deformational texture.The Muslim Bagh and Khanozai chromitites are classified into high-Cr chromitite(Cr#=0.66-0.85)while Zhob chromitite falls into high-Al chromitite(Cr#=0.53-0.58)composition.
基金The Science and Technology Planning Project of Guangzhou(No.202206010064)Natural Science Foundation of Guangdong Province,China(2021A1515010566)The National Key Research and Development Program of China(2016YFD0200405-5)for financially supporting this work.
文摘The use of inorganic nitrogen(N)fertilizers has increased drastically to meet the food requirements of the world’s growing population.However,the excessive use of chemical nitrogen fertilizer has caused a series of soil and environmental problems,such as soil hardening,lower nitrogen use efficiency(NUE),nitrate pollution of water sources,nitrous oxide emissions,etc.In this review,we aimed to elaborate and discuss the role of engineered biochar in inducing the stability of water-stable macroaggregates,improving inorganic N transformation,and utilization efficiency to address the current uncertainties of nitrogen loss and maintaining soil and water quality.Firstly,we elucidated the characteristics of engineered biochar in improving biochar quality to work as a multifunctional player in the ecosystem and promote resource utilization,soil conservation,and ecosystem preservation.Secondly,we discussed how the engineered biochar modulates the stability of water-stable macroaggregates and soil inorganic nitrogen transformation to enhance plant response under various toxic or deficient nitrogen conditions in the soil.Thirdly,the role of engineered biochar in biological nitrogen fixation,mediating nirK,nirS,and nosZ genes to promote the conversion of N_(2)O to N_(2),and decreasing denitrification and N_(2)O emission was reviewed.Altogether,we suggest that engineered biochar amendment to soil can regulate soil water-stable macroaggregates,reduce N input,improve nitrogen metabolism,and finally,NUE and crop growth.To the best of our knowledge,this is the first time to evaluate the combined interactions of"engineered biochar×soil×NUE×crop growth,"providing advantages over the increasing N and water utilization and crop productivity separately with the aim of enhancing the stability of water-stable macroaggregates and NUE together on a sustainable basis.
