Geomagnetic Excursion

Abstract

David (1904) and Brunhes (1906) were the first to measure magnetization directions in rocks that were approximately antiparallel to the present Earth's field. Brunhes (1906) recorded magnetizations in baked sedimentary rocks that were aligned with reverse magnetization directions in overlying Miocene lavas from central France (Puy de Dome). In so doing, Brunhes (1906) made first use of a field test for primary thermal remanent magnetization (TRM) that is now referred to as the 'baked contact' test (see Laj et al. (2002) for an account of Brunhes' work). Matuyama (1929) was the first to attribute reverse magnetizations in (volcanic) rocks from Japan and China to reversal of geomagnetic polarity, and to differentiate mainly Pleistocene lavas from mainly Pliocene lavas based on the polarity of the 373