Work

Near‐Synchronous Cambrian Evolution of the Transbrasiliano‐Kandi‐4°50′ Shear Zone in South America and Africa

Year: 2025

Type: article

Abstract: ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that the TK4 represents a near‐synchronous transcontinental shear zone system. While U–Pb zircon dates represent Archean to Neoproterozoic protolith crystallization and high‐grade metamorphism ages that are not reset during mid‐temperature shearing, dextral ductile shearing is constrained by metamorphic apatite U–Pb and syn‐kinematic biotite Rb‐Sr dates averaging 511 ± 16 and 505 ± 7 Ma, respectively. Thus, ca. 30–60 Ma after the last collisional events at ca. 570–540 Ma, the whole Brasiliano/PanAfrican orogen was reworked through the development of early Cambrian major interlinked systems of strike‐slip shear zones (keirogens).

Source: Terra Nova

DOI: 10.1111/ter.70017

Authors: F. A. Caxito, B. V. Ribeiro, F. Alkmim, A. Deramchi, C. L. Kirkland

Institutions: Universidade Federal de Minas Gerais, Curtin University, Universidade Federal de Ouro Preto, Centre de Recherche en Astronomie Astrophysique et Géophysique

Language: English

Topic: Geological and Geochemical Analysis

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,720

Funders: Curtin University of Technology, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Instituto Serrapilheira