Special issue  

Rhönite in the Cenozoic alkali basalts of the Changle area occurs as a reaction product; the host basalts are generated in an extensional setting of intracontinent and are tectonically located above the old subduction zone. Rare-earth-element patterns of rhönite resemble those of kaersutitic amphibole and kaersutite. Compositions of Changle rhönites covering the two types of metasomatic mantle amphiboles further suggest that rhönite could be seen as the role of petrogenetic indicator mineral.

There have been many different ages found for ophiolite. We have researched these ages through fieldwork and microscopy to identify three types of dunite. These are useful ways to research the origin of ophiolitic magma. The Purang ophiolite, which crops out over an area of about 650 km² in the western Yarlung–Zangbo suture zone, chiefly consists of mantle peridotite, pyroxenite and gabbro. It is a useful ultra-massif for showing the multistage nature of ophiolite.