SUMMARY

Zircon U-Pb isotope ages of rhyolite eruption rocks and periods of lead-zinc mineral formation in the Khâu Lộc structure - Northeast Vietnam

Đỗ Quốc Bình, Phạm Trung Hiếu, Nguyễn Thị Bích Thủy

The Khâu Lộc structure zone covers the eastern and northeastern part of the Việt Bắc uplift block. The zone is composed mainly of terrigenous sedimentary rocks, quartz-sericite schist interbed of rhyolite tuff, carbonate sedimentary rocks that have different age and lead-zinc mineralization. The formation ages of two rhyolite erupted rock samples determined by U-Pb zircon isotopes on LA-ICP-MS is 835 and 441 Ma, corresponding to the Neoproterozoic and Paleozoic time. The analytical results of Pb-Pb isotope on galenite extracted from ore samples taken from lead-zinc ore veins interbeding in sericite schist, limestone-dolomite and rhyolite yielded model ages concentrated at 700-590 and 532-368 Ma. In combination with the U-Pb zircon isotopic age determined in this study, it can be said that lead-zinc mineralization in the Khâu Lộc structure zone is formed at least in two periods of time that are Neoproterozoic and Paleozoic.