RESULTADOS PRELIMINARES DE AMS DEL PALEOZOICO DE LAS ISLAS MALVINAS

MILANESE, FLORENCIA N.; VILAS, JUAN; CALVIÑO, MARTÍN; FRANCESCHINIS, PABLO R.; TOMEZZOLI, RENATA; RAPALINI, AUGUSTO E.

Río de Janeiro

Congreso; LatinMag VII Biennal Meeting; 2023

Asociación Latinoamericana de Paleomagnetismo y Geomagnetismo

We present preliminary results of anisotropy of magnetic susceptibility (AMS) frommarine sedimentary units of Silurian to Carboniferous age exposed at Shag Cove(-51.7370 °S; -59.6552 °W), in the eastern margin of the Gran Malvina Island. Samplingwas conducted in a field trip carried out in late 1981, and a total of ~4,000 m ofsedimentary thickness was sampled. From a total of 160 samples, 45 present negativebulk magnetic susceptibilities (k < 0) and were discarded from this preliminary analysis.The remaining samples show an average k value of 40.5E-6 SI (n=115). Magnetic fabricsare mostly oblate and subordinately prolate. 70 samples show very low k valuesbetween 0 and 20E-6 SI, while maximum value reaches up to ~2E-4 SI. After beddingcorrection, it is observed that kmin axes tend to group, amid some dispersion, in asubvertical position, suggesting a dominant sedimentary fabric.