Understanding the enhanced magnetization intensities of post-20 Ma oceanic basalts through magneto-mineratogical experiments

海洋玄武岩的磁化强度随时间变化，在海洋磁异常剖面中清晰可见。从现在到过去，强度下降，直到20 Ma左右，然后他们稳步增加，直到白垩纪。最初的强度下降可以解释为钛磁铁矿的低温氧化为钛磁赤铁矿;然而，年龄大于20 Ma的大洋玄武岩随后磁化强度增加的原因尚不清楚。我们建议测试磁性矿物学变化是磁化强度增加的根本原因的可能性。两个潜在的磁性矿物学的变化，设想都将结合电子探针分析，古强度实验和岩石磁性表征检查。原子力显微镜（AFM），磁力显微镜（MFM）或穆斯堡尔光谱也将根据情况使用。采用这种新的，尖端的技术与更经典的实验一起应该大大限制了地球科学中的一阶，但仍然没有解决的问题。

The magnetization intensities of oceanic basalts vary through time, being clearly visible in marine magnetic anomaly profiles. Going from the present to the past, intensities decrease until around 20 Ma, and then they steadily increase until the Cretaceous. The initial decrease in intensity can be explained by low temperature oxidation of titanomagnetite to titanomaghemite; however, the cause for the subsequent increase in magnetization for oceanic basalts older than 20 Ma is unknown. We propose to test the possibility that magneto-mineralogical changes are the underlying cause of the magnetization increase. Two potential magneto-mineralogical changes are envisaged—both will be examined by combining electron microprobe analyses, paleo-intensity experiments and rock magnetic characterization. Atomic Force Microscopy (AFM), Magnetic Force Microscopy (MFM) or Mössbaur spectroscopy will also be employed depending on the case. Employing this new, cutting-edge technology together with the more classical experiments should significantly constrain a first-order, yet still unresolved, problem in the Earth sciences.