The NW Amazonian Craton in Guainía and Vaupés departments, Colombia: Evidence of a Mesoproterozoic thermal event from apatite LA-ICP-MS U-Pb geochronology and its relation to continental rifting - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Precambrian Research Année : 2023

The NW Amazonian Craton in Guainía and Vaupés departments, Colombia: Evidence of a Mesoproterozoic thermal event from apatite LA-ICP-MS U-Pb geochronology and its relation to continental rifting

Résumé

New U-Pb LA-ICP-MS apatite ages in E-Colombian rocks and previously obtained U-Pb LA-ICP-MS zircon ages allow us to reconstruct the tectonomagmatic history of the NW-Amazonian Craton during the Mesoproterozoic. Four amphibolite-facies migmatites from the Mitú Complex area yield apatite U-Pb ages between 1405 ± 10 to 1359 ± 31 Ma, whereas five granitoids from the same area display ages between 1436 ± 31 to 1344 ± 40 Ma. Towards the west, six granitoids outcropping in the Inírida River area yield ages between 1416 ± 31 and 1368 ± 32 Ma which overlap within uncertainties to the 1409 ± 33 Ma old Matraca Rapakivi granite.The new apatite U-Pb ages of ca. 1450–1340 Ma indicate Early Mesoproterozoic thermal overprinting of a Paleoproterozoic basement that had reached peak conditions during the Querarí Orogeny ca. 1850–1720 Ma and was subsequently intruded by post-collisional to anorogenic granitoids ca. 1600–1500 Ma. The Early Mesoproterozoic thermal event affected indiscriminately the whole basement, which is coeval to the Nickerie-K’Mudku major shearing and mylonitization episode. However, the thermal event also strongly relates to large anorogenic magmatism in a continental rift, evidencing at least two rifting stages between 1550 and 1340 Ma.Middle Mesoproterozoic anorogenic intraplate magmatism in East Colombia has been recognized as a major event that affected the NW-Amazonian Craton, possibly following Early Mesoproterozoic uplift and major extension. The latter processes might be depicting the rifting and subsequent stabilization of the Amazonian craton. The early stages of rifting between 1550 and 1400 Ma were coeval to the Parguaza Granite (Ta, Nb, Sn, REE, U) ore deposits in Venezuela and as well as the (W, Ta, Nb, REE, U) ore deposits at the Cerro Tigre, San Jose, Barranquilla, and Taraira sites in Colombia, whereas, the late rift stage between 1400 and 1340 Ma is coeval to the Espina hill (Ta, Nb, REE, U) ore deposit. The new information indicates that anorogenic magmatic episodes were intimately related to the emplacement of REE-rich ores in the northwestern Amazonian Craton during Early to Middle Mesoproterozoic times.

Domaines

Géochimie
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Dates et versions

insu-04181489 , version 1 (16-08-2023)

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Amed Bonilla, Jose Franco Victoria, Thomas Cramer, Johan de Grave, Simon Nachtergaele, et al.. The NW Amazonian Craton in Guainía and Vaupés departments, Colombia: Evidence of a Mesoproterozoic thermal event from apatite LA-ICP-MS U-Pb geochronology and its relation to continental rifting. Precambrian Research, 2023, 395, pp.107148. ⟨10.1016/j.precamres.2023.107148⟩. ⟨insu-04181489⟩
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