Magnetostratigraphy and Carbon isotopes of Ediacaran Avellaneda Formation, Rio de La Plata Craton, Argentina

• DOI: 10.5194/egusphere-egu2020-1162
• Publication Date: 2020-03-09T12:31:46Z
• Authors: Jhon Afonso; Ricardo Trindade; Pablo Franceschinis; Augusto Rapalini
• Keywords: Magnetostratigraphy

<p>The Ediacaran Period (635-542 Ma) witnessed a series of extraordinary events. It arises with the end Marinoan Glaciation and deposition worldwide enigmatic cap carbonate deposits. This abrupt shift in paleoclimatic conditions coincides major fluctuations the  isotope ratios carbon sulfur, significant changes concentration redox-sensitive elements marine sediments. The is also period marked by rapid geomagnetic polarity. Magnetostratigraphy may therefore provide high-resolution correlation between successions worldwide. Here, we combine stratigraphy logs, isotopes magnetostratigraphy on Avellaneda Formation (590-560 which at Rio La Plata Craton, eastern Argentina. We investigated two drill cores (TSE-34 TSE-7) 0.3-0.7 m resolution covering entire Formation, corresponding to 98 standard specimens (25 mm diameter). basal contact underlying mudstone rocks from Loma Negra (~ 590 present both cores. upper Alicia only observed TSE-34 core, transitional. TSE-7 displays an erosional Avellenda Cerro Negro Formations 560 Ma). After stepwise thermal demagnetization up 600°C, almost all samples provided characteristic magnetization 350°C Ti-poor magnetite or titanohematite likely main carrier stable remanence these rocks. A high-temperature, dual-polarity component persistent coherent base unit normal polarity, followed reverse interval, polarity across part Formation. magnetostratigraphic framework, together signal, will be compared results recently obtained for potentially coeval China, Canada United States.</p>