“…Early investigations of the Mariana region were driven by the discovery of hydrothermal activity in the central back‐arc during a series of Alvin dives in 1987, which located the Alice Springs (including Central Peak), Burke (including Snail Pits and Anemone Heaven), and Illium vent fields near 18°12'N, and the Central Trough vent field near 18°2'N [ Craig et al ., ; Campbell et al ., ; Hessler et al ., ; Hessler and Martin , ; Hessler and Lonsdale , , Gamo and Shipboard Scientific Party , ; Fujikura et al ., ; Ishibashi et al ., ]. Venting was subsequently discovered in the southern back‐arc near 13°N, beginning with the Forecast Seamount vent field in 1992 [ Johnson et al ., ; Gamo and Shipboard Scientific Party , ], the 13°N Ridge low‐temperature vent field in 1999 [ Mitsuzawa et al ., ; Masuda et al ., ], the Snail (also known as the “Fryer” site), Yamanaka (also known as the “Y” site), Pika, and Archean (3030–2980 mbsl) vent fields in 2003, and the Urashima vent field in 2010 [ Wheat et al ., ; Ishibashi et al ., ; Urabe et al ., ; Baker et al ., ; Kakegawa et al ., ; Yoshikawa et al ., ; Nakamura et al ., ; Ikehata et al ., ]. However, the regional geological context of the different vent sites was poorly understood.…”