3He in the Bransfield Strait waters: indication for local injection from back-arc rifting

• Published in: Deep Sea Research Part A. Oceanographic Research Papers
• Main Authors: Schlosser, Peter, Suess, Erwin, Bayer, Reinhold, Rhein, Monika
• Format: Article in Journal/Newspaper
• Language: English
• Published: Pergamon Press 1988
• Subjects: Bransfield Strait; Drake Passage; Weddell; Weddell Sea
• Online Access: https://oceanrep.geomar.de/id/eprint/33349/; https://oceanrep.geomar.de/id/eprint/33349/1/Schlosser.pdf; https://doi.org/10.1016/0198-0149(88)90117-3

Helium data from the waters of the Bransfield Strait, the southern Drake Passage and the northwestern shelf of the Weddell Sea are presented. The 3He profiles from the eastern and central basins of the Bransfield Strait show maxima (δ3He ≈ 7%) below the sill depths that separate the strait from the surrounding open ocean. The 3He excess is interpreted as a local injection of a 3He-rich helium component into the deep waters of the Bransfield Strait from backarc rifting. Tritiogenic 3He and excess 3He from mixing with Circumpolar Deep Water are excluded as possible sources. The estimated 3He/4He ratio of the injected helium component (2.4–5.0 × 10−6) is less than that of pure mantle helium and may contain radiogenic helium from continental crustal material which underlies the Bransfield Strait.