Geochronologic evidence of a large magmatic province in northern patagonia encompassing the Permian-Triassic boundary

LUPPO, TOMAS; LOPEZ DE LUCHI, MONICA G; RAPALINI, AUGUSTO E.; MARTINEZ DOPICO, C.I.; FANNING, C. MARK

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2018 vol. 82 p. 346 - 355

0895-9811

The Los Menucos Complex (northern Patagonia) consists of ¡­6km thick succession of acidic and intermediatevolcanic and pyroclastic products, which has been traditionally assigned to the Middle/Late Triassic. NewU/Pb (SHRIMP) zircon crystallization ages of 257¡¾2 Ma at the base, 252¡¾2 Ma at an intermediate level and248¡¾2 Ma near the top of the sequence, indicate that this volcanic event took place in about 10 Ma aroundthe Permian-Triassic boundary. This volcanism can now be considered as the effusive terms of the neighboringand coeval La Esperanza Plutono-Volcanic Complex. This indicates that the climax of activity of a largemagmatic province in northern Patagonia was coetaneous with the end-Permian mass extinctions. Likely correlationof La Esperanza- Los Menucos magmatic province with similar volcanic and plutonic rocks acrossother areas of northern Patagonia suggest a much larger extension than previously envisaged for this event. Itsage, large volume and explosive nature suggest that the previously ignored potential role that this volcanismmight have played in climatic deterioration around the Permian-Triassic boundary should be investigated