- Being located in southeastern margin of the Qinghai-Tibet Plateau, the Ailaoshan gold belt is one of the economically most significant gold production bases in China.
Since the 1980s, Mojiang gold deposit (large scale), Zhenyuan (super large scale and was called as Laowangzhai gold deposit in the early literatures) gold deposit, Daping gold deposit (super large scale) and Changan gold deposit (large scale), and a series of small- to medium-sized gold deposits and mineralization points have been discovered.
Re and Os become concentrated in the organic, hydrogenous fraction of organic rich shales, thus the time when the shale was deposited can be dated.
The technique can be applied to any organic rich shale older than ~10 Ma and can include lacustrine and Proterozoic shales for which biostratigraphical information is lacking.
In recent years, with the large-scale development of open pits and emerging, some new geological phenomenon, more and more evidences show that genesis of the Zhenyuan gold deposit is closely related to the ophiolite melange belt distributed in the region.
In this study, Re-Os dating of the auriferous pyrite from Zhenyuan gold deposit was determined by HRICP-MS, in order to provide the isotopic evidences for the metallogenic age and the ore-forming material sources.
In general, between six and eight samples from the same stratigraphic interval are analysed to produce an isochron that provides a Re - Os age for the deposition of the shale with a typical uncertainty of between 1% and 5%.