Rock magnetic properties and paleomagnetic behavior of Neogene marine sediments from northern Chile

Abstract

Neogene sediments from La Portada and Bahia Inglesa formations located at Mejillones Peninsula and Caldera Port, northern Chile carry multicomponent magnetizations, which can lead to misidentification of the characteristic paleomagnetic vector and consequently, errors in chronostratigraphic and structural interpretation of the strata. Here we present a complete rock magnetic and paleomagnetic behavior study of Neogene sediments from La Portada and Bahia Inglesa formations. Isothermal remanent magnetization, thermal-magnetic susceptibility, magnetic hysteresis, and X-ray diffractometer experiments are combined with paleomagnetic, alternating field, and thermal demagnetization data to determine magnetization history. Remanent magnetizations generally comprises three components: a low blocking temperature (Tb) component, below 150 C, close to the present-day field in direction, interpreted as a thermoviscous component; an