The Ore-forming Fluid Characteristics And Genesis Of The Danaya W-Mo Deposit,Inner Mongolia

Dayana tungsten and molybdenum disposit is a small and medium-sized quartz vein type tungsten deposit,which discovered recently in Dongwuqi area.The regional metallogenic location belongs to the south part of the dongwuqi-nenjiang metallogenic belt of the daxinganling metallogenic belt.This paper is based on the systematic summary of previous research results.This paper focuses on the study of fluid inclusions in the main metallogenic stage of the deposit,the microscopic temperature measurement,the composition analysis of the inclusions and the stable isotope geochemistry characteristics,The properties,evolution rules and metallogenic mechanism of metallogenic fluid are discussed.The main points are as follows:?1?Dayana tungsten and molybdenum disposit is a quartz vein type tungsten Deposit,the ore body mainly occurred in the upper part of the biotite granite rock mass and zone of surrounding rock fracture.And the metallogenic process can be divided into four stages:quartz-muscovite stage???,quartz-molybdenum mineralization stage???,quartz-tungsten mineralization stage???and quartz-vein stage???.Including?and?phase main mineralization stage for the deposit.?2?There are four main types of inclusions in the Dayana tungsten and molybdenum disposit:?type inclusions?Rich liquid phase two-phase inclusion?,?type inclusions?Contains three phase inclusions of submineral?,?type inclusions?Rich gas phase inclusions?,?type inclusions?Single liquid phase inclusion?;Type of?type inclusions are the main types of the ore deposit,more than90%of the total number of inclusions,also is a focus in the study of this article.The contents of the inclusions were mainly H₂O,The subminerals may be mineral crystals that crystallize early in the magma water.?3?The average temperature of the inclusions in the danna-tungsten molybdenum deposit is concentrated in 220?to 325?,salinity w?NaCl,eq?range from 1 to 7.The quartz-molybdenite stage homogenization temperatures of fluid inclusions are mainly concentrated in 250?to 320?,salinity w?NaCl,eq?range from 1 to 4,quartz-wolframite stage homogenization temperatures mainly concentrated in 220?to 320?,salinity w?NaCl,eq?range from 1.74 to 8.95.The laser Raman results suggested that mineralize-related fluids were the medium-high temperature and medium-low salinity NaCl-H₂O fluid system.?4?The hydrogen and oxygen isotopes characteristics in fluid inclusions indicate that the metallogenic fluid is mainlyderived from magma water and mixed a small amount of atmospheric precipitation.On the basis of the comprehensive view,the tungsten molybdenum deposit is a medium-high temperature hydrothermal deposit,and the mineralization is related to the granite body.?5?Through the study and analysis of the average temperature and salinity of the inclusions in the deposit,the main mechanism of the sedimentation of molybdenum deposit and the deposit of tungsten deposit in the mining area is considered as the boiling action and the temperature drop.On the basis of the comprehensive view,the tungsten molybdenum deposit is a medium-high temperature hydrothermal deposit,and the mineralization is related to the granite body.