Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Sonne1	SO229	01.07.2013 - 27.07.2013		South Pacific Ocean

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Haase Karsten	Friedrich-Alexander Universitat Erlangen	Townsville	Noumea (New Caledonia)	Karte Map

Ziel der Reise / Objectives of Cruise:

Young rifting in the southern New Hebrides island arc formed three volcanically and hydrothermally active basins of the Coriolis Trough where alkaline lavas with enrichments in Nb and Ta were recovered. The steep faults of the rifted arc present the opportunity to sample up 7 Ma old crust. A detailed stratigraphic sampling of the rift flanks and the young volcanoes in the southern island arc and in the backarc allows to study magma evolution and variation of sources. Three sites of hydrothermal activity are known from the Coriolis Troughs but have not been sampled in detail. We address the evolution of metallogenetic processes and fluid dynamics and the effects of variable water depths on magma degassing and composition of hydrothermal fluids. Biological work will concentrate on community descriptions in order to understand habitat controls on the distribution of species and the composition of vent faunal assemblages. RV Sonne arrived in Vanuatu waters on Saturday, July 6th and the first dive of Kiel6000 took place on July 8th at the northern edge of Epi caldera. Signs of hydrothermal venting became abundant close to the apparently tectonic structure east of Cioan. Systematic traversing of the hydrothermal plume led to the finding of a large area with active and inactive hydrothermal venting. The emanating fluid had temperatures of about 20?C, some 6?C warmer than the surrounding seawater. White bacterial mats cover large regions of the northern slope of an apparently faulted block of the caldera rim between 330 and 320 m depth. No signs of recent volcanic activity were observed but the venting apparently followed linear features interpreted as tectonic faults. Iron oxide forms large mounds and thick layers on the seafloor and fields with small inactive oxide chimneys were observed. Work continued by sampling the different volcanic cones in the Epi Caldera using the TV grab and alltogether some 65 volcanic rock samples. On July 11th we finished with the work in Epi and headed south to Vate Trough. Weather conditions on the 12th were fine and the ROV went on a track from west to east across the eastern part of the caldera of Nifonea volcano in Vate Trough. White staining and shimmering water as well as white smoke was abundant and when traversing the hydrothermal field the ROV two black smokers were found at the base of a slope of fresh pillow lava. Sulfides and fluids were sampled from an about 3 m tall chimney and we also took samples from the underlying lava and the organisms of the hydrothermal vents. Following the dive we carried out several TV grab, wax corer and CTD stations (numbers 028 to 037) on Nifonea volcano and recovered fresh lava samples and water from the plume. MAPRs were deployed on each station and show a wide distribution of the hydrothermal plume in the eastern part of the caldera. RV Sonne turned further south and we began work with 039ROV dive in the shelter of Futuna island. The dive recovered 12 volcanic rock samples from the steep faulted cliffs between water depths of 3200 and 2100 m. Work with the TV grab recovered fresh lava samples from a volcanic cone and ridge between Futuna Trough and Tanna island whereas a grab on Sineto volcano yielded Fe oxide crusts. We took about 70 rock samples from Nifonea volcano which ranged from old Mn-covered lavas from the area outside of the caldera to fresh glassy lavas from the caldera. On July 21st dive 072ROV was carried out that sampled the southern rift wall of Vate Trough and 21 volcanic rock samples were taken between 2000 and 1500 m depth. RV Sonne steamed southwards and two TV grab stations were carried out on a 500 m shallow seamount between Vate and Erromango Troughs. Mapping of the western rim of Erromango Trough was resumed and the final TV grab was taken on a young volcanic cone NE of Sineto volcano. On the late afternoon of July 24th RV Sonne started its way to Noumea where it arrived on the morning of July 26th.

Messungen / Measurements