The full vector field of Earths earliest geodynamo

The primary objective of the proposed research is, through the use of numerous state-of-the-art techniques, to obtain reliable measurements of the full-vector of the geomagnetic field from some of the oldest rocks on Earth. The information that this will provide about the core of the Earth during its early history will constitute a dramatic step forward in our understanding of the evolution of the planet?s deep interior. The Earth?s magnetic field is of vital importance: compass and navigation discovered the world, and it protects life on Earth from harmful cosmic and solar radiation. The field is generated in the fluid outer core, but the influence of the solid inner core is important in strengthening and stabilizing the field. The present field is well known, through satellite observations, but the ancient field is increasingly less known. In particular, during Earth?s earliest history, 3.5 to 2 billion years ago, the character of the field is still a mystery. It is possible that the Earth had no solid inner core, although estimates range from 3.5 to 1.0 Ga. Within this period, life began, during a time that the field may have been weaker, and the Sun?s radiation many times higher than today. We intend to characterise the full vector of the early field, using the oldest possible paleomagnetic record. We anticipate that our results will be of fundamental importance for advancing numerical geodynamo models, and models on early solar radiation and atmospheric composition.