ABSTRACT We present a paleomagnetic and rock magnetic record from a 465.2 m long drill core recovered at DSDP Site 277 in the Southwest Pacific. Our study sought to construct a magnetostratigraphy and thus enable further paleoenvironmental work on this sedimentary succession. Magnetic remanence measurements revealed a stable magnetisation in the upper 34.8 m and lower 58.7 m of the core. However, between 34.8 and 397.5 m sediments are very weakly magnetised, do not carry a stable magnetisation, and rock magnetic analyses revealed a lack of remanence carrying minerals in this interval. We suggest that during the period spanning Paleocene to Oligocene sufficiently high organic matter (reagents) accumulation resulted in complete reduction and dissolution of ferri/ferromagnetic grains.

中文翻译：

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西南太平洋 DSDP Site 277 磁性矿物的成岩作用

摘要 我们展示了在西南太平洋 DSDP 站点 277 回收的 465.2 m 长钻芯的古地磁和岩石磁记录。我们的研究试图构建磁地层学，从而能够对这一沉积层序进行进一步的古环境工作。剩磁测量显示，磁芯上部 34.8 m 和下部 58.7 m 的磁化强度稳定。然而，在 34.8 和 397.5 m 之间的沉积物磁化非常弱，没有稳定的磁化，并且岩石磁性分析显示该层段缺乏携带剩磁的矿物。我们认为，在古新世到渐新世期间，足够高的有机质（试剂）积累导致铁/铁磁颗粒的完全减少和溶解。