Abstract:

The 302 uranium deposit, located at the eastern part of the Zhuguangshan granite composite in northern Guangdong
province which is the most important large ore-concentrated area of granite-hosted uranium deposit in China, is a large-scale, deeply
buried and largely vertical mineralized granite-hosted uranium deposit. Uranium ore bodies occur mainly as vein type, flat beanpod-like
and lens-like, and are hosted within hydrothermally altered fault zones in the Indosinian Youdong granite and the early Yanshanian
Changjiang granite. And the dominant uranium-bearing mineral is pitchblende. Despite intensive research over the past few decades,
the source of ore-forming fluid and ore-forming material of this uranium deposit remains controversial. The results of hydrogen and
oxygen isotopes in this article show that δDH2O and δDH2O values of ore-forming fluids range from -7.09‰ to 3.24‰ and from -105‰
to -63‰ , respectively, indicating that ore-forming fluids were mainly formed by deeply circulating meteoric water which have

experienced water-rock interaction. The relatively low δDH2O value may be caused by hydrothermal boiling action of ore-forming fluids
or mixing up with small amount of organic water ( δOH2O -90‰ to -250‰) in the process of deep circulation. The εNd(t) values (-11.9
to -11.4) and rare earth element distribution patterns of the fluorite of metallogenic period are similar to those of the Changjiang granite
but obviously different from those of the Youdong granite. Fluorites are in or near the scope of Changjiang granite in Gd/Yb-Nb/Ta
diagram, indicating that uranium source of the 302 deposit was mainly derived from the Changjiang granite.

Key words: Isotopes；source of ore-forming fluid and ore-forming material；uranium deposit 302；South China