6.4 Geochemistry

Five samples of the Gumburanjun leucogranite (Table 6.1, fig. 6.10) were analysed for major and trace element composition by Jean-Claude Vannay (unpubl. data). We incorporate these data in this work to compare them with chemical analyses made by Ferrara et al. (1991) on the same intrusion and data from Herren (1987, data from Brouand and Pêcher included) on several leucogranitic sheets and dikes from NW Zanskar (region of Padum). This set of data from Zanskar is also compared with chemical analyses made by Guillot (1993) on the Manaslu leucogranite in Nepal, which represents the largest and most studied Himalayan leucogranitic intrusion.

The purpose is to show that the chemical composition of the leucogranites is not only very homogenous within the same intrusion but also between different intrusions, even if they are separated by several hundred kilometres as for Zanskar and Nepal.