New dating method: Groundwater residence time estimated from the 4He accumulation rate calibrated by using cosmogenic and subsurface-produced 36ClY. Mahara, T. Ohta, T. Kubota, K. Miyakawa, T. Hasegawa, M. A. Habermehl and L. K. FifieldEPJ Web of Conferences, 24 (2012) 03002DOI: https://doi.org/10.1051/epjconf/20122403002