This paper aims to evaluate ecological benefits of maize harmful and beneficial elements in Hetao agricultural economic zone. Maize rhizosphere soil,seed,stem and leaf samples are collected from Hetao agricultural eco...This paper aims to evaluate ecological benefits of maize harmful and beneficial elements in Hetao agricultural economic zone. Maize rhizosphere soil,seed,stem and leaf samples are collected from Hetao agricultural economic zone in Inner Mongolia,and the content of poisonous,harmful and beneficial elements is analyzed. The main harmful elements account for a small proportion in maize seeds and stems,and most of them are at low enrichment level; most of the beneficial elements are at low enrichment level,and only N is at high enrichment level.The content of As,Pb,Cd,Hg,Cr,Cu and As in maize rhizosphere soil is lower than the national standard,in line with the green standard,and the environment conditions of producing area are excellent. Maize in the study area is pollution-free food,which can be used as sustenance for human and animal.展开更多
Thallium (Tl) is a dispersed element and it seldom occurs in the form of independent minerals. So the element is hard to form any independent deposit. The world annual production of Tl is about 13 ton, most of which i...Thallium (Tl) is a dispersed element and it seldom occurs in the form of independent minerals. So the element is hard to form any independent deposit. The world annual production of Tl is about 13 ton, most of which is recovered as by\|product from non\|ferrous metal metallurgical products. Reported in this paper is the only large\|sized independent Tl deposit in the world, of which the Tl ores can be mined, ore\|dressed and smelted independently. Bio\|enrichment and hydrothermal reworking are the two important metallogenic mechanisms of this Tl deposit. This paper will give a discussion to the Lanmuchang Tl deposit in the following respects including its geological characteristics, element association of Tl, Hg, As and Au and W, sulfur isotopic composition, involvement of hallogens in metallogenesis and the metallogenic models.展开更多
Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of...Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.展开更多
基金Supported by Ecological Geochemical Investigation in Hetao Agricultural Economic Zone(200414200005)
文摘This paper aims to evaluate ecological benefits of maize harmful and beneficial elements in Hetao agricultural economic zone. Maize rhizosphere soil,seed,stem and leaf samples are collected from Hetao agricultural economic zone in Inner Mongolia,and the content of poisonous,harmful and beneficial elements is analyzed. The main harmful elements account for a small proportion in maize seeds and stems,and most of them are at low enrichment level; most of the beneficial elements are at low enrichment level,and only N is at high enrichment level.The content of As,Pb,Cd,Hg,Cr,Cu and As in maize rhizosphere soil is lower than the national standard,in line with the green standard,and the environment conditions of producing area are excellent. Maize in the study area is pollution-free food,which can be used as sustenance for human and animal.
文摘Thallium (Tl) is a dispersed element and it seldom occurs in the form of independent minerals. So the element is hard to form any independent deposit. The world annual production of Tl is about 13 ton, most of which is recovered as by\|product from non\|ferrous metal metallurgical products. Reported in this paper is the only large\|sized independent Tl deposit in the world, of which the Tl ores can be mined, ore\|dressed and smelted independently. Bio\|enrichment and hydrothermal reworking are the two important metallogenic mechanisms of this Tl deposit. This paper will give a discussion to the Lanmuchang Tl deposit in the following respects including its geological characteristics, element association of Tl, Hg, As and Au and W, sulfur isotopic composition, involvement of hallogens in metallogenesis and the metallogenic models.
基金the National Natural Science Foundation of China (Grant No. 40372047)
文摘Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.
