Phanerozoic low-temperature evolution of the Uruguayan Shield along the South American passive margin

• Published in: Journal of the Geological Society
• Main Authors: Hueck, Mathias, Oriolo, Sebastián, Dunkl, István, Wemmer, Klaus, Oyhantçabal, Pedro, Schanofski, Max, Stipp Basei, Miguel Angelo, Siegesmund, Siegfried
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Soc Publ House
• Subjects: -; https://purl.org/becyt/ford/1.5; https://purl.org/becyt/ford/1; Argentina; Uruguay; Klaus; South Atlantic Ocean
• Online Access: http://hdl.handle.net/11336/66401

The crystalline basement of Uruguay was assembled during the Brasiliano Orogeny in the Neoproterozoic Era and was later affected by discrete tectonic activity. A new multi-method low-temperature dataset including (U-Th)/He ages from both zircon and apatite, T-t modelling and K-Ar dating of fine sericite fractions and fault gouge reveal a detailed post-orogenic geological history spanning the Phanerozoic Eon. The juxtaposition of the terranes that compose the area was achieved in the Ediacaran Period, and post-collision was marked by intense exhumation, in which the crystalline basement reached near-surface conditions by the early to mid-Palaeozoic. Regional subsidence promoted sedimentation in the Paraná Basin until the Permian, covering and reheating much of the basement that is at present exposed. Afterwards, deposition and volcanism were mostly confined to its current limits. Regional exhumation of the shield during the Permo-Triassic exposed much of the northern portion of the basement, and the south was further affected by the opening of the South Atlantic Ocean during the Mesozoic. Little exhumation affected the Uruguayan Shield during the Cenozoic, as reflected in its modest topography. The reactivation of inherited Neoproterozoic structures influenced the development of Mesozoic basins and the present-day landscape. Fil: Hueck, Mathias. Universität Göttingen; Alemania Fil: Oriolo, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universität Göttingen; Alemania Fil: Dunkl, István. Universität Göttingen; Alemania Fil: Wemmer, Klaus. Universität Göttingen; Alemania Fil: Oyhantçabal, Pedro. Universidad de la Republica. Instituto de Ciencias Geológicas; Uruguay Fil: Schanofski, Max. Universität Göttingen; Alemania Fil: Stipp Basei, Miguel Angelo. Universidade de Sao Paulo; Brasil Fil: Siegesmund, Siegfried. Universität Göttingen; Alemania