Natural gamma radiation and miscellaneous material from IODP Hole 348-C0002P - Hirose, Takehiro; Saffer, Demian M; Tobin, Harold J; Toczko, Sean; Maeda, Lena; Kubo, Yusuke; Kimura, Gaku; Moore, Gregory F; Underwood, Michael B; Kanagawa, Kyuichi; Expedition 348 Scientists (PANGAEA, 2015)