颗粒破碎铀同位素年代学在风尘系统中的应用

Application of Uranium Isotope Chronology for Partical Comminution in the Eolian Dust System

风尘系统是陆地表层系统的重要组成部分,对诸多关键带有着重要作用。风尘的产生机制与搬运过程对理解风尘的环境功能和解读风尘沉积的古气候记录至关重要。以往传统地球化学方法只能反映最终剥蚀区的岩性或矿物结晶年龄,无法区分相同最终物源背景下不同粉沙的产生机制和搬运中间过程,是当前风尘研究的最大挑战之一。由α衰变反冲导致的细粒物质的234U/238U值反映颗粒自破碎以来经历的时间,可能能有效示踪粉尘的产生机制以及搬运中间过程,但是铀同位素破碎年代学在风尘系统中还鲜有应用。总结了限制铀同位素广泛应用的复杂因素,并根据最新的研究进展,针对在风尘系统中验证和发展铀同位素破碎年代学,以及解决风尘产生机制和搬运路径等问题展开讨论。

The wind dust system is an important part of the terrestrial surface system and plays an important role in many key belts. The mechanism of wind dust and the handling process are important to understand the envi ronmental function of wind dust and to interpret the paleoclimate record. In the past, traditional geochemical meth ods can only reflect the rock composition or age in the final denudation zone, and it is not possible to distinguish the different silt mechanism and the intermediate process under the same eventual source background, which is one of the biggest challenges of the present research. The 234U//238U ratio of fine matter caused by alpha decay recoil re fleets the time experienced by the particle since it was broken and may be able to effectively trace the mechanism of wind dust generation and the transport of the intermediate process, but the age of uranium isotope fragmentation is rarely used in the wind dust system. The complicated factors restricting the wide application of uranium isotope were summarized, and according to the latest research progress, the verification and development of the uranium isotope comminution age in the wind dust system, and the problem solution of the mechanism of wind dust production and the way of transporting were discussed.