Device and method for quantifying 4He in mineral particles, and uranium-thorium/helium dating method

Abstract

The invention belongs to the technical field of oil exploration, and relates to a device for quantifying 4He in mineral particles. The quantifying device comprises a laser heating system, a purification and enrichment system, a standard sample mixing system, a detection and analysis system, an automatic control and data processing system and a vacuum processing system, and the laser heating system, the purification and enrichment system and the detection and analysis system sequentially communicate in series; the laser heating system is used for heating the mineral particles, so that the mineral particles release gas, and the gas is extracted and contains 4He; the purification and enrichment system is used for purifying and enriching 4He in the gas; the standard sample mixing system comprises a 4He standard quantitative tube, a 4He standard tank communicating with the 4He standard quantitative tube, a 3He dilution quantitative tube and a 3He dilution tank communicating with the 3He dilution quantitative tube; the 4He standard quantitative tube and the 4He standard tank are connected with the 3He dilution quantitative tube and the 3He dilution tank in parallel; and the detection andanalysis system is used for detecting the content of 4He and 3He. The content of 4He in the mineral particles can be accurately detected through one-time sample injection by utilizing an isotope dilution method.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploration, more specifically, relates to a kind of 4 He quantification apparatus and method and uranium-thorium / helium dating method. Background technique [0002] (U-Th) / He dating is based on the disintegration of U and Th radioactive elements in mineral particles such as apatite and zircon 4 He and mineral particles enter the He closed system due to a certain geological event at a certain temperature point to start the geological clock for dating. It is a new technology for low-temperature thermochronology research that has developed rapidly in recent years. The / He age refers to the time from the cooling of the rock to the closure of the corresponding minerals from the (U-Th) / He system to the present. It records the structural evolution history of minerals after they have experienced closure temperature. Geomorphic evolution and sediment source analysis have been widely used, especially i...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the given uranium-lead age is the crystallization age, which can only provide thermochronological information of geological bodies under high-temperature conditions, and cannot provide historical information of low-temperature thermal evolution

The disadvantage of this method is that the fission track dating is obtained by the length and density of particle tracks produced in the process of nuclear decay of apatite and zircon, and the dating accuracy is relatively low

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