Magnetic inference of in situ open microcracks in sandstone samples from the Taiwan Chelungpu Fault Drilling Project (TCDP)

► We investigate the magnetic signature of microcracks in TCDP sandstone. ► Anisotropy of anhysteretic remanent magnetization reflects magnetite neocrystallizations into microcracks network. ► Microcracks in TCDP sandstone are open at depth.