Airborne geophysical characterization of Uruguayan basement. (June 2021)

• Record Type: Journal Article
• Authors: Sánchez Bettucci, Leda; Loureiro, Judith; Núñez Demarco, Pablo
• Is Part Of: Journal of South American earth sciences. Volume 108(2021)
• Publication Date: 2021-06
• Subjects: Geophysical survey -- Magnetic and gamma-ray spectrometric data -- Airborne methods -- Uruguay; Geology -- Latin America -- Periodicals; Earth sciences -- Latin America -- Periodicals; Geology -- Antarctica -- Periodicals; Earth sciences -- Antarctica -- Periodicals; Geology -- Caribbean Area -- Periodicals; Earth sciences -- Caribbean Area -- Periodicals; Géologie -- Amérique latine -- Périodiques; Sciences de la terre -- Amérique latine -- Périodiques; Géologie -- Antarctique -- Périodiques; Sciences de la terre -- Antarctique -- Périodiques; Géologie -- Caraïbes (Région) -- Périodiques; Sciences de la terre -- Caraïbes (Région) -- Périodiques; Earth sciences; Geology; Antarctica; Caribbean Area; Latin America; Periodicals; 550.5
• DOI: 10.1016/j.jsames.2021.103206
• Languages: English
• ISSNs: 0895-9811

Abstract

Abstract: The integrated observation of geology, gammaspectrometry and magnetometry of southern Uruguay was made possible by the high-resolution aerogeophysical survey carried out during 2014 and 2015. This survey covers nearly the outcropping area of the Uruguayan basement. Previous studies focused on the Proterozoic and Mesozoic dike swarms present in the Uruguayan basement. In this work we address features previously undescribed and unstudied in the Uruguayan basement. Structures previously grouped with the dike swarm are separated (subcircular structures and a lava river) and the basement general patterns were studied. Distinctive magnetic and radiometric features characterize each structural block in the Uruguayan basement, supporting the main tectonic units previously described, but improving the location of their limits. Highlights: The Piedra Alta Terrain of the RPC is delimited from the adjacent units through the magnetic and radiometric survey. Shear zones and thrust belts are recognized, mainly through magnetometry. Magnetometry allowed the recognition of different dike swarms, particularly in the Punta del Este Terrane. A major U and Th anomaly occurs over to the Illescas rapakivi granite. The Valentines Formation is differentiated from the Nico Pérez Terrane basement.