Demagnetization of rock as an evidence of extraterrestrial impact (Acraman and Santa Fe impact structures)
Abstrakt
Impact cratering is a unique energetical process that shapes solid planetary surfaces in our universe. Here on Earth the surfaces modified by impacts are quickly disappearing due to large surface mobility caused by weathering and erosion, driven by occurrence of life on Earth, precipitation, and plate tectonics.
While there are many features on Earth surface that can be interpreted as due to an extraterrestrial impact, there are only few tools that allow providing a supporting evidence for terrestrial impact origin. These are PDFs (planar deformation features, mostly observed in quartz crystals), and shatter cone fabric (observed in outcrop scale).
While there are additional potential observation features that are commonly associated impacts (microspherules [1], micro/nano diamonds [2], high temperature melting [3], gravity surface morphology [4]) these are not unique and may be related to processes other than impact. Recent work on Santa Fe structure has pointed out a potential novel feature, plasma assisted demagnetization, that may be considered as a unique terrestrial impact indica