Campaign to the South Pacific
A small tag team of the O2rigin group travelled to the South Pacific in early 2017. During the six weeks of their stay they did fieldwork in the Kingdom of Tonga. Focus of the work was to obtain fresh rock samples from the volcanic islands in the area. Being part of the circumpacific "Ring of Fire", these islands formed from ascending mantle melts in response to the westward subduction of the Pacific plate beneath the Australian plate. As these remote volcanic islands are located far from continental landmass, their rocks bear information on subduction-related magmatism devoid of crustal contamination, perhaps similar to geological times when continent-derived materials played a less significant role as today. Such pristine, intraoceanic subduction zone processes may be regarded as an geodynamic endmember scenario, which constitutes one point of interest for the O2rigin project.