The Jizhong-Yanbian Cu-Mo-Au-Pb-Zn polymetallic metallogenic belt is a major nonferrous and precious metal resource base in Northeastern China.The genesis of ore deposits in this district has remained controversial.To...The Jizhong-Yanbian Cu-Mo-Au-Pb-Zn polymetallic metallogenic belt is a major nonferrous and precious metal resource base in Northeastern China.The genesis of ore deposits in this district has remained controversial.To constrain ore genetic models and provide information for exploration,we conducted precise Zn-Cd isotopic measurements on sphalerite and galena.Theδ^(66)Zn_(AA-ETH)values of galena and sphalerite range from−0.07‰to 0.03‰and−0.68‰to−0.12‰,respectively;and theirδ^(114/110)Cd_(NIST SRM 3108)values vary from−0.96‰to 3.83‰and−0.63‰to 0.77‰,respectively.Our study suggests that the Xiaohongshilazi Pb-Zn-(Ag)deposit should be classified as a Mississippi Valley Type(MVT)-like deposit,because both its geological,sulfide trace elemental,and S-Pb-Fe-Zn-Cd isotopic characteristics are similar to those of the typical MVT deposit,except for the differences of the wall rocks.Rayleigh fractionation during sphalerite precipitation is identified as the primary mechanism for Zn-Cd isotopic variations,which is validated by the Zn-Cd fractionation models from 100℃to 250℃.Finally,we propose an ore prospecting model based on migration pathways of ore-forming fluid and the Zn isotopic fractionation model of sphalerite under 100℃.This model indicates potential resources undiscovered at shallow/peripheral and deep zones of current mining level in both the Eastern and Western Ore Block,with parts of the potential resources having been corroborated by recent drilling.Despite the complexity of mineralization,processes,this study provides new insights into the application of Zn-Cd isotopes in understanding ore genesis and guiding mineral exploration in similar contexts.展开更多
In an acetic acid–sodium acetate buffer solution of pH 3.6–6.8, a compound complex was formed between sodium hyaluronate (abbreviated as SH) and some basic bisphenylnaphthylmethane dyes, leading to a great enhanceme...In an acetic acid–sodium acetate buffer solution of pH 3.6–6.8, a compound complex was formed between sodium hyaluronate (abbreviated as SH) and some basic bisphenylnaphthylmethane dyes, leading to a great enhancement of the intensity of resonance Rayleigh scattering (RRS) and giving a new RRS spectrum, with its maximum scattering peak near 280 nm. It was also found that the intensity of RRS was directly proportional to the concentration of SH near the range between 0 and 3.0 mg/L. Based on these facts, a sensitive method for the determination of SH has been established. The method had good selectivity, and has been used for the determination of total amounts of SH in samples with satisfactory results. For the NB–SH system, the detection limit of SH was down to 13.7 ng/mL.展开更多
基金supported by the Open Research Project from the Young Elite Scientists Sponsorship Program by BAST(No.BYESS2023411)the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(GPMR202407)the Enterprise Authorized Item from Jilin Sanhe Mining Development Co.LTD(3-4-2021-120).
文摘The Jizhong-Yanbian Cu-Mo-Au-Pb-Zn polymetallic metallogenic belt is a major nonferrous and precious metal resource base in Northeastern China.The genesis of ore deposits in this district has remained controversial.To constrain ore genetic models and provide information for exploration,we conducted precise Zn-Cd isotopic measurements on sphalerite and galena.Theδ^(66)Zn_(AA-ETH)values of galena and sphalerite range from−0.07‰to 0.03‰and−0.68‰to−0.12‰,respectively;and theirδ^(114/110)Cd_(NIST SRM 3108)values vary from−0.96‰to 3.83‰and−0.63‰to 0.77‰,respectively.Our study suggests that the Xiaohongshilazi Pb-Zn-(Ag)deposit should be classified as a Mississippi Valley Type(MVT)-like deposit,because both its geological,sulfide trace elemental,and S-Pb-Fe-Zn-Cd isotopic characteristics are similar to those of the typical MVT deposit,except for the differences of the wall rocks.Rayleigh fractionation during sphalerite precipitation is identified as the primary mechanism for Zn-Cd isotopic variations,which is validated by the Zn-Cd fractionation models from 100℃to 250℃.Finally,we propose an ore prospecting model based on migration pathways of ore-forming fluid and the Zn isotopic fractionation model of sphalerite under 100℃.This model indicates potential resources undiscovered at shallow/peripheral and deep zones of current mining level in both the Eastern and Western Ore Block,with parts of the potential resources having been corroborated by recent drilling.Despite the complexity of mineralization,processes,this study provides new insights into the application of Zn-Cd isotopes in understanding ore genesis and guiding mineral exploration in similar contexts.
文摘In an acetic acid–sodium acetate buffer solution of pH 3.6–6.8, a compound complex was formed between sodium hyaluronate (abbreviated as SH) and some basic bisphenylnaphthylmethane dyes, leading to a great enhancement of the intensity of resonance Rayleigh scattering (RRS) and giving a new RRS spectrum, with its maximum scattering peak near 280 nm. It was also found that the intensity of RRS was directly proportional to the concentration of SH near the range between 0 and 3.0 mg/L. Based on these facts, a sensitive method for the determination of SH has been established. The method had good selectivity, and has been used for the determination of total amounts of SH in samples with satisfactory results. For the NB–SH system, the detection limit of SH was down to 13.7 ng/mL.
