During China’s Ming Dynasty (1368-1644), Tibet was completely independent under three Tibetan ruling houses.
In 1642, the Great Fifth Dalai Lama created the Ganden government, with a unique monastic/secular-coordinated administration.
The Chinese and foreign geologists had long-term research on geochronology of igneous rocks in Tibet since 1964 when the first K-Ar isotopic age data on Tibet has been published by Prof.
Li, who worked in a scientific expedition of Tibet Academy Sciences.
This was our first organized tour, and we were a bit wary of how it would work. As the tour went on, we were happier and happier with our decision.
It is both important scientific and practical significance to make full use of these valuable data collested from nature condition scurviness areas, clean up and dig out some useful information among them.
It has been shown that the climax and valley of magmatic activity just corresponds to that of tectonic activity and vice versa.
However, they display features similar to common magmatic zircon, including euhedral crystal habit, high Th/U ratios and enriched heavy rare earth elements pattern.
We suggest that these zircon grains formed from a different reservoir from that for garnet where no trace elements was present and trace element equilibrium between zircon and garnet was achieved.