SUMMARY

Outlines on the Ca Vịnh Complex through the geological mapping and mineral survey at 1:50.000 scale of the Văn Chấn map sheet group

La Mai Sơn, Phạm Thanh Bình, Nguyễn Trần Hùng,

Đinh Văn Thắng, Trần Ngọc Diễn

The Ca Vịnh Complex has a large distributive area on the territory of Văn Chấn District, Yên Bái Province, belonging to the Phan Si Pan structural zone that has been attracting the attention of many geologists, which have different viewpoints about the origin of this complex. On the basis of materials on geology, petrography, mineralogy and petrochemistry, preliminary results of the geological mapping and mineral survey at 1:50.000 scale of the Văn Chấn map sheet group let see that granitoids of the Ca Vịnh Complex occur only in the form of small massifs, nearly conformable with the structural direction of the Suối Chiềng Formation. The rocks of the complex belong to the calc-alkaline series, excessive in sodium, of the I-granite type. They are the ultrametamorphic products of the Suối Chiềng Formation and have been dated as Mesoarchean.

Người biên tập: Trần Tất Thắng.