Detrital zircon U-Pb ages and Hf isotopic characteristics of the Mbala Formation in the northeast Bangweulu Metacraton, Zambia

The activity time and crustal growth of Bangweulu Metacraton have always been the focus of geologists. This paper studied the detrital zircon U-Pb ages and Hf isotopic characteristics of quartz sandstone from the Mbala Formation in Kapatu area. Based on the previous results of Bangweulu Metacraton, the paper has obtained the following understanding: (1) The Mbala Formation might formed between (1833±22 Ma) and (1712±22 Ma), belonging to the Paleoproterozoic. (2) The Mbala Formation is rich in material sources, among which the material of 2728 ~ 2602 Ma (peak age is 2650 Ma) may be derived from granitoids, trachyandesite, rhyolite and other rocks in Tanzania Craton. The material of 2246~1833 Ma (peak age is 1880 Ma) is mainly derived from granitoids, quartz diorite, volcanic rocks and other rocks in the Bangweulu Block. (3) The activity time of the Bangweulu Metacraton includes Middle Archean, Neoarchean, Paleoproterozoic and Mesoproterozoic. The Paleoproterozoic (1870 Ma) was the peak of the activity, which may be closely related to the evolution of the Columbia Supercontinent. (4) In addition to the recycled materials from the ancient crust, the crust accretion in the source area of the Bangweulu Metacraton sedimentary rocks also contains new crust materials. The crust has achieved growth from Paleoarchean to Paleoproterozoic, with the fastest growth in Kenorland Supercontinent convergence (Neoarchean 2550 Ma). Before Paleoproterozoic, the main growth period of the Bangweulu Metacraton is basically the same as the Tanzania Craton and the global continental crust.