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Reorienting the West African craton in Paleoproterozoic–Mesoproterozoic supercontinent Nuna

2021; Geological Society of America; Volume: 49; Issue: 10 Linguagem: Inglês

10.1130/g48855.1

1943-2682

Zheng Gong, David A.D. Evans, Nasrrddine Youbi, Abdelhak Ait Lahna, Ulf Söderlund, Malika Ait Malek, Bin Wen, Xianqing Jing, Jikai Ding, Moulay Ahmed Boumehdi, Richard E. Ernst,

earthquake and tectonic studies

Abstract The location of the West African craton (WAC) has been poorly constrained in the Paleoproterozoic–Mesoproterozoic supercontinent Nuna (also known as Columbia). Previous Nuna reconstruction models suggested that the WAC was connected to Amazonia in a way similar to their relative position in Gondwana. By an integrated paleomagnetic and geochronological study of the Proterozoic mafic dikes in the Anti-Atlas Belt, Morocco, we provide two reliable paleomagnetic poles to test this connection. Incorporating our new poles with quality-filtered poles from the neighboring cratons of the WAC, we propose an inverted WAC-Amazonia connection, with the northern WAC attached to northeastern Amazonia, as well as a refined configuration of Nuna. Global large igneous province records also conform to our new reconstruction. The inverted WAC-Amazonia connection suggests a substantial change in their relative orientation from Nuna to Gondwana, providing an additional example of large-magnitude cumulative azimuthal rotations between adjacent continental blocks over supercontinental cycles.