A-type magmatism in a syn-collisional setting: The case of the Pan-African Hook Batholith in Central Zambia

摘要: Abstract The Pan-African Hook Batholith formed during the assembly of Gondwana supercontinent as a result syn-collisional stage interaction between Congo and Kalahari Cratons. bimodal magmatism (mafic to predominantly felsic) is characterized by both an alkali-calcic alkalic suite, with typical A-type, metaluminous, high Fe/Mg K/Na geochemical signature. Occasionally, sodic granitoids have been documented. Compositions were driven more differentiated products fractional crystallization, while Sr–Nd isotopes exclude crustal assimilation crystallization. Recent new U–Pb age data constrain most felsic 550 540 Ma. Scattered outcrops gabbroic rocks, tholeiitic alkaline, testify periodic input mantle material, and, in some cases, metasomatizing fluids. Crystallization ages on mafic rocks span from 570 520 Ma, thus indicating that they contemporaneous major granitic intrusion, which was number successive batches, eventually forming coalescing batholith. Highly radiogenic Pb isotopic values attest character rocks. Such anomalous signature acquired during, or soon after, magma emplacement, perhaps Enrichment Th–U large portions crust along this part margin Craton suggested. Geochemical evidence support components deep at pressure