Geomagnetic Field Paleointensity during the Cretaceous Normal Superchron from Marine Magnetic Anomalies

The knowledge of the geomagnetic field intensity during the Cretaceous Normal Superchron, a long term of forty million years without polarity reversals, may have a large impact on our understanding of the dynamo process occurring in Earth’s outer core. How, it is difficult to get the geomagnetic field behavior during the Cretaceous Normal Superchron resulting from the inadequate sampling or data of variable qualities from igneous rocks and sedimentary. Here we examine 20 magnetic anomaly profiles across the Cretaceous magnetic quiet zone of the Central Atlantic Ocean in the African flank extracted from the EMAG2v3, and calculate a synthetical magnetization profile based on the forward modeling method. We suggest that this profile records the high strength of geomagnetic field at the beginning of ~30 million years and low signal during the late period, which could be correlated with the low-resolution relative paleointensity record from the sediment samples at the Falkland Plateau, and which also could be found the VDMs/VADMs averaged by a 7-Ma sliding window from the absolute intensity records mostly from the MagIC database. Our results support the hypothesis that the distribution of heat flow along the core-mantle boundary is positively correlative to the intensity of the dipole field.