Datación magnetoestratigráfica de la cuenca terciaria de As Pontes (Galicia, NW de España)

Abstract

The Tertiary Basin of As Pontes (Northwest Spain) has been dated by means of magnetostratigraphy. A total of four local magnetostratigraphic successions have been constructed. In the four succesions 500 sites were sampled at an average spacing of aproximately 2 m. The minerai is that carriy the magnetisation in the studied rocks are magnetite and iron sulphides. Correlation to CPTS show that sedimentation in the basin began before the end of the Chron 7 Or with an age of 2 8 .7 M y and i t lasted, at least, until the end of the subchron 6AAr.2n with an age of 22.5 My. The duration of the sedimentation in the basin was about 6.2 My, and it comprises from the upper most Early O ligocenefupper part of the Stampian) to the Early Miocene (upper A quitanian)