This dataset contains raw noble gas data from water samples collected during the cruise SO301 at the Rodriguez Tripple Junction, Indian Ocean. Samples were taken either with the CTD rosette water sampling system (CTD) or with a trace-metal-free titanium rosette (TMR) from the Constructor University Bremen. As the TMR has no live data connection to the ship, sample bottles are closed by pre-progamming pressure thresholds. The decision for sampling depths was in general guided by previous CTD casts at the same location. Additional metadata was taken from the corresponding rosette system. The stations were executed in winter 2023/24 to detect possible hydrothermal plumes at the Kairei Vent Site and to assess the dispersal of hydrothermal plumes. From the isotope ratio different water masses can be distinguished. The samples were taken from Niskin bottles into gas tight copper tubes and transported to the Bremen Helium Isotope Laboratory. For the analysis, the samples were extracted with an ultra high vaccum system and transferred into a fully automated mass spectrometric system, which is composed of a two stage cryogenic chamber and a quadrupole and a sector-field mass spectrometer. The system as well as the performance is described in detail in Sültenfuß et al. (2009). The results of double samples taken for control purposes were averaged.

Nml/kg, mass concentration = normal milliliter per kilogram