Paleointensity of the geomagnetic field in the Late Cretaceous and earliest Paleogene obtained from drill cores of the Louisville seamount trail

摘要: Information on the strength of geomagnetic field is important for understanding behavior geodynamo. Polarity reversal frequency increases toward late Cenozoic since end Cretaceous Normal Superchron. Accumulating reliable paleointensity data in this time interval still desired elucidating possibility a link between and paleointensity. We conducted study 288 samples from four seamounts ∼74 to ∼50 Ma age that constitutes Louisville seamount trail. Based thermomagnetic curves scanning electron microscopy, we first excluded 134 showed evidence low-temperature oxidation. then applied Tsunakawa-Shaw method with demagnetization double heating after rejecting some do not preserve stable primary remanence, 52 successful results were obtained. An average virtual axial dipole moment (VADM) 3.75 ± 1.52 (1022 Am2) was obtained at Site U1372 Canopus (∼74 Ma) based 16 independent measurements. Sites U1373 U1374 Rigil (∼70 yielded mean 3.79 ± 1.40 (n = 16), U1376 Burton (∼65 3.70 ± 1.37 (n = 8). These VADMs are similar long-term last 200 Myr by Tauxe et al. (2013) 5 Yamamoto Tsunakawa (2005). The volcanic sequence drilled probably belongs Chron C33n 5.59 long, whereas others belong shorter chrons. Our support no discernible relationship polarity length