Trace Elements And Thermoelectricity Typomorphic Characteristics Of Pyrite In Gold Deposits Of Different Types

Pyrite is one of the most important gold-bearing minerals in gold deposits, which accounts for 85 of the total amount of gold deposits as the main gold bearing minerals. Therefore studying typomorphic characteristics of pyrite deeply are helpful for prospecting of gold deposits. This paper summarizes six types of gold deposits, including quartz vein type, Carlin type, altered (shattered) rock type, Skarn type, breccia type and mesothermal and epithermal type. Analysis of their typomorphic characteristics of pyrite, especially the trace elements and thermoelectricity characteristics reveal the laws and the relationships of different gold deposit types.Contents and variation trends of trace elements in pyrite are similar in different types of gold deposits, which show relatively rich in As、Cu、Pb、Zn, and poor in Gr、 Sn、V、T1. The quartz vein type gold deposit has relatively poor content of Ni in pyrite, and its Co/Ni ratio is mainly between 1-5, Au/Ag ratio is less than 10. Carlin type is rich in As, but poor in Co, Ni. The contents of trace elements in pyrite of Skarn type are generally low. Breccia type is obviously rich in Co, poor in As, Ni. Standard deviation characteristics of Fe and S indicate that the complex sequence of ore forming material and ore forming environment is:mesothermal and epithermal type, Carlin type, altered rock type, quartz vein type, breccia type and Skarn type from large to small.The thermoelectricity characteristics of different types of gold deposits have regularity. Among the six gold deposit types, quartz vein type thermoelectric coefficients (a) value of pyrite range smallest. The occurrence rate of P-type pyrite (P) in Carlin type and its thermoelectric coefficients distribute widely, but performance double peak with the highest value in thermoelectricity ratio histogram. Altered rock is also concentrated into two areas. The thermoelectric coefficients value of breccia type is low on the whole, as well as its P value; while the thermoelectric coefficients of mesothermal and epithermal type distribute uniformly.Analyzing the normal distribution of ∑As/∑(Co+Ni)ratio and the occurrence rate of P-type pyrite of six types turn out that:The two parameters’normal curves of breccia type gold deposit are very fitting:both are positive skewness towards the right which shows that the metallogenic environment of breccia type gold deposit is complex and diverse.The temporal and spatial distribution of gold deposits can be revealed with the characteristics of P-type thermoelectricity and trace elements in pyrite. Through analysis of the typical gold deposit-Linglong gold district in the Xishan gold deposit, conclusion can be drawn as followed:The P-type pyrite has four cyclicity distribution features in the vertical direction (from 380m to-225 m level). This indicates that in the vertical direction, P、the element combination (Co+Ni)、(As+Sb+Se+Te) and (Cu+Zn) are all fluctuating, and the overall rate is decreasing with the downward extension of the ore body. So it indicates that orebodies Nos.108-1 and 107 extend more than 700m in the vertical direction in Xishan gold deposit, and the potential exploration targets for the continuation of these orebodies are mainly located toward the northeast.