Geomagnetic secular variations 1880–1480 A.D. as recorded by sediments from laguna Potrok Aike

C. S. G. GOGORZA

Bremen

Seminario; Seminar der AG Geopolar; 2010

Geomorphologie und Polarforschung (GEOPOLAR) / Institut fuer Geographie, FB 8 de la Universidad de Bremen (Alemania)

High resolution secular variation curves of geomagnetic inclination, declination recorded on lacustrine sediment from laguna Potrok Aike for the period 1880-1480 A.D. were obtained. The NRM15mT is carried by (titano)-magnetite of grain size 4-15 µm (PSD) and the mineral concentration varies between 0.01 and 0.08%. The analysis of the curvature of the Bauer plots shows that clockwise and counter clockwise directions are present, with a preponderance of counter clockwise movement. The observed consistency of the PSV records in the south western of Argentina confirms, in a preliminary way, that PSV dating may be valuable for historical data on a regional scale. The relative paleointensity records obtained for laguna Potrok Aike shows that ARM15mT is the best normaliser for these sediments. Our normalised intensity record shows reasonable good agreement with the model gufm1.