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Mata Tolu

Name Alias(es): 
North Mata
MGDS_FeatureID lowest in hierarchy: 
Maximum Temperature: 
Max Temperature Category: 
Location on map: 
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Maximum or Single Reported Depth (mbsl): 
Minimum Depth (mbsl): 
Tectonic setting: 
Volcano Number (if applicable): 
Host Rock: 
Deposit Type: 
Notes on Vent Field Description: 
one of the 7 volcanoes in the North Mata volcanic complex; classified here as arc volcano, but at the 2018 AGU Fall Meeting this tectonic setting was distinguished as rear-arc and the region was distinguished as NE Lau Basin; NEL9_Dredge 1: "Native Sulphur associated with vesicles ... Live Mussels still attached to oxide-stained surface" (; "Line NEL 9c was then completed with detection of a strong plume signal on top of the ridge at the junction of the previous RV Thompson tow line. Water samples were sampled and 2 bottles filtered for particulates. Dark colored particulates were observed under a binocular microscope. This area is considered a new target for Nautilus Minerals."; "A strong sulphur smell permeated everything recovered including numerous large live mussels, one large snail and a worm. No sulfide mineralization was observed. Clearly, a low temperature hydrothermal vent field was dredged."; Baker et al. (2010): "The 25-km-long chain of “Mata” volcanoes lies ... separated from both the arc front and the spreading ridge", "Camera tows confirmed the location of active vents fields on the ... summit of Mata Tolu (∼1800 m)"; SRK report (2011): "Along the ridge crest of the Mata Tolu feature, a plume was intercepted at ~2200m, and also on the summit. The recovered video confirms diffuse venting and chimney structures, just short of the ridge crest on the south side."; 2012 cruise blog, accessed 24 April 2015, "hydrothermal area was a mixture of active and inactive structures with a maximum recorded temperature of 271 C"; Baker et al. 2019: site 37 in Table 2;
Notes Relevant to Biology: 
mussels; video of "Snails Temperature Preferences", dive Q331, accessed 24 April 2015,
Year and How Discovered (if active, visual confirmation is listed first): 
2010 towed camera; 2009 plume and dredge only
Discovery References (text): 
Baker, E.T., et al. (2010) Multiple Active Volcanoes in the Northeast Lau Basin. AGU Fall Meeting Abstract #T13B-2188;
Cruise SS02/2009: Hydrothermal plume and structural geology mapping in the Tonga/Fiji region (;
Crowhurst et al. (2009) Discovery of new hydrothermal venting sites in the Lau Basin, Tonga Back-Arc. AGU Fall Meeting abstract #OS13A-1180;
Other References (text): 
SRK Consulting (2011) Nautilus Minerals Incorporated NI43-101 Technical Report 2010 PNG, Tonga, Fiji, Solomon Islands, New Zealand, Vanuatu and the ISA. Document Reference: NAT007 Nautilus 43-101 Technical Report 2011 Rev3.docx;
2012 cruise report, accessed 6 May 2015:;
Baker ET, Walker SL, Massoth GJ and Resing JA (2019) The NE Lau Basin: Widespread and Abundant Hydrothermal Venting in the Back-Arc Region Behind a Superfast Subduction Zone. Front. Mar. Sci. 6:382. doi: 10.3389/fmars.2019.00382;