Unprecedented U-Pb-Th SHRIMP and Lu-Hf isotopic data in zircon from Tandilia basement rocks, Argentina: new insights into Palaeoproterozoic and Neoproterozoic crustal reworking of the Rio de la Plata craton

Angeletti, Melisa; Chichorro, Martim Afonso; Castro, Antonio; Frisicale, María Cristina; Solá, A. Rita; Dimieri, Luis Vicente; Martinez, Juan Cruz

http://hdl.handle.net/10400.9/6141

Use this identifier to reference this record.

Name:	Description:	Size:	Format:
PrecambrianResearch_vol.430_107941.pdf		168.66 KB	Adobe PDF	Download

Send Feedback

Authors

Angeletti, Melisa

Chichorro, Martim Afonso

Castro, Antonio

Frisicale, María Cristina

Solá, A. Rita

Dimieri, Luis Vicente

Martinez, Juan Cruz

Abstract(s)

ABSTRACT: We present new geochronological zircon data from the Siempre Amigos Hill (SAH), a small but representative portion of Tandilia Terrane within the R & iacute;o de la Plata Craton (RPC). U-Pb-Th SHRIMP data indicate a heterogeneous Palaeoproterozoic (Rhyacian) crust. A garnet-bearing granite (2165 +/- 16 Ma) hosts felsic (2108 +/- 13.6 Ma) to intermediate gneiss protolith (2104 +/- 8 Ma), andesite with a sanukitoid signature (2094 +/- 47 Ma) and granulites or charnockites. Additionally, calc-alkaline granitoids (2092 +/- 13 Ma) intruded, as a result of differentiation from an igneous mafic sanukitoid source. Localised low-temperature shear zones affected the sequence. Lu-Hf isotopic data for the post-orogenic stage (< 2.1 Ga) complement previous results, showing progressive negative epsilon Hf-(t) values. These isotopes suggest post-orogenic transtension. New Neoproterozoic ages (652 +/- 37 Ma, 618.4 +/- 11.2 Ma and 686 +/- 60 Ma) from granites, with low-to-very low zircon Th/U ratios, are presented as evidence of U-Th-Pb systems overprinting by Neoproterozoic (Cryogenian) thermal-hydrothermal events. Those Neoproterozoic ages are, within analytical uncertainty, equivalent to the 656 +/- 19 Ma metamorphic age obtained for the Palaeoproterozoic granulite. These new Neoproterozoic ages, suggests a thermal perturbation linked either to the collision of the Nico Perez Terrane against the passive margin of RPC, or the Neoproterozoic evolution of the Ventania System basement during the Brasiliano/ Pan-African orogeny.

Keywords

Geology Isotopes Zircon U-Pb geochronology Palaeoproterozoic Neoproterozoic

URI

http://hdl.handle.net/10400.9/6141

Citation

Angeletti, M., Chichorro, M., Castro, A., Frisicale, M.C., Solá, R., Dimieri, L.V. & Martinez, J.C. (2025). Unprecedented U-Pb-Th SHRIMP and Lu-Hf isotopic data in zircon from Tandilia basement rocks, Argentina: new insights into Palaeoproterozoic and Neoproterozoic crustal reworking of the Rio de la Plata craton. In: Precambrian Research, 2025, vol. 430, article 107941. https://doi.org/10.1016/j.precamres.2025.107941