DOCSLIB.ORG

Hydrothermal System, Brothers Volcano, Kermadec Island Arc

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Hydrothermal System, Brothers Volcano, Kermadec Island Arc Contributions to Mineralogy and Petrology (2018) 173:40 https://doi.org/10.1007/s00410-018-1470-5 ORIGINAL PAPER Constraints on the source of Cu in a submarine magmatic- hydrothermal system, Brothers volcano, Kermadec island arc Manuel Keith1 · Karsten M. Haase2 · Reiner Klemd2 · Daniel J. Smith1 · Ulrich Schwarz‑Schampera3 · Wolfgang Bach4 Received: 15 December 2017 / Accepted: 17 April 2018 / Published online: 21 April 2018 © The Author(s) 2018 Abstract Most magmatic-hydrothermal Cu deposits are genetically linked to arc magmas. However, most continental or oceanic arc magmas are barren, and hence new methods have to be developed to distinguish between barren and mineralised arc systems. Source composition, melting conditions, the timing of S saturation and an initial chalcophile element-enrichment represent important parameters that control the potential of a subduction setting to host an economically valuable deposit. Brothers volcano in the Kermadec island arc is one of the best-studied examples of arc-related submarine magmatic-hydrothermal activity. This study, for the first time, compares the chemical and mineralogical composition of the Brothers seafloor massive sulphides and the associated dacitic to rhyolitic lavas that host the hydrothermal system. Incompatible trace element ratios, such as La/Sm and Ce/Pb, indicate that the basaltic melts from L’Esperance volcano may represent a parental analogue to the more evolved Brothers lavas. Copper-rich magmatic sulphides (Cu > 2 wt%) identified in fresh volcanic glass and phe- nocryst phases, such as clinopyroxene, plagioclase and Fe–Ti oxide suggest that the surrounding lavas that host the Broth- ers hydrothermal system represent a potential Cu source for the sulphide ores at the seafloor. Thermodynamic calculations reveal that the Brothers melts reached volatile saturation during their evolution. Melt inclusion data and the occurrence of sulphides along vesicle margins indicate that an exsolving volatile phase extracted Cu from the silicate melt and probably contributed it to the overlying hydrothermal system. Hence, the formation of the Cu-rich seafloor massive sulphides (up to 35.6 wt%) is probably due to the contribution of Cu from a bimodal source including wall rock leaching and magmatic degassing, in a mineralisation style that is hybrid between Cyprus-type volcanic-hosted massive sulphide and subaerial epithermal–porphyry deposits. Keywords Brothers volcano, Kermadec arc · Magmatic sulphides · Hydrothermal sulphides · Magmatic degassing · Melt inclusions · Epithermal–porphyry deposits · VHMS deposits Introduction Communicated by Timothy L. Grove. Magmatic-hydrothermal systems along convergent plate Electronic supplementary material The online version of this margins host some of the Earth’s most important porphyry article (https ://doi.org/10.1007/s0041 0-018-1470-5) contains Cu–Mo and epithermal Au–Ag–Te deposits (Seedorff et al. supplementary material, which is available to authorized users. 2005; Simmons 2005; Sillitoe 2010). Most of these met- * Manuel Keith als are considered to be derived from fluids of magmatic [email protected] origin that exsolved from mid- to upper crustal magma chambers (Richards 2011). Recent studies have shown that 1 School of Geography and Geology, University of Leicester, submarine hydrothermal systems associated with island arc Leicester LE1 7RH, UK volcanism can be affected by a magmatic volatile compo- 2 GeoZentrum Nordbayern, Universität Erlangen-Nürnberg, nent similar to their subaerial counterparts (de Ronde et al. 91054 Erlangen, Germany 2005, 2014). Brothers volcano in the Kermadec island arc 3 Bundesanstalt für Geowissenschaften und Rohstoffe, represents one of the best-studied examples of arc-related 30655 Hanover, Germany submarine magmatic-hydrothermal activity; and fluid and 4 Fachbereich Geowissenschaften der Universität Bremen, sulphide chemistry suggest a magmatic volatile contribution 28334 Bremen, Germany Vol.:(0123456789)1 3 40 Page 2 of 16 Contributions to Mineralogy and Petrology (2018) 173:40 (de Ronde et al. 2005, 2011; Keith et al. 2016a). In addition enriched in incompatible trace elements and volatiles (e.g., to a magmatic volatile signature, acid-sulphate (advanced S and Cl) compared to mid-ocean ridge magmas (Wallace argillic) alteration, sulphosalts (e.g., enargite, Cu 3AsS4) 2005; Richards 2011; Kelley and Cottrell 2012; Lee et al. typical for high-sulphidation conditions (Einaudi et al. 2012). This discrepancy results in higher S concentrations at 2003) and high contents of economically important met- sulphide saturation (Fortin et al. 2015), and hence sulphide als (e.g., Cu and Au) in some submarine arc and back-arc segregation typically occurs later during magmatic differen- hydrothermal systems imply that they may be comparable tiation, perhaps triggered by Fe–Ti oxide fractionation and to epithermal–porphyry deposits on land, such as the world- decreasing fO2 (Jenner et al. 2010; Keith et al. 2017; Patten class Far Southeast-Lepanto Cu–Au deposits (Philippines; et al. 2017). However, distinguishing these different pro- Hedenquist et al. 1998). This includes, for example, the mag- cesses and parameters is still challenging and often ambigu- matic-hydrothermal systems of Brothers volcano (Kermadec ous (Hedenquist and Lowenstern 1994) and our knowledge arc; de Ronde et al. 2005; Berkenbosch et al. 2012) and about the interaction between the magmatic and hydrother- Kolumbo volcano (Hellenic arc; Kilias et al. 2013, 2016), mal system and its control on the composition of associated as well as SuSu Knolls in the Manus back-arc basin (Crad- ore deposits is limited. dock and Bach 2010; Craddock et al. 2010; Yeats et al. 2014; This study combines the chemical and mineralogical Thal et al. 2016). Hence, arc-hosted hydrothermal systems composition of magmatic and hydrothermal sulphides with are characteristically distinct in terms of their chemical and silicate glass and melt inclusion data for the first time to mineralogical composition compared to those along mid- constrain the source characteristics and main enrichment ocean ridges, which were interpreted to be the classic mod- processes of Cu in an island arc-hosted magmatic-hydro- ern analogues of volcanic-hosted massive sulphide (VHMS) thermal system. deposits mined on land (Hannington et al. 1998, 2011; de Ronde et al. 2014; Keith et al. 2016b). High bulk ore contents of certain metals and semi-metals, Geological setting and sample localities such as Cu (up to 27 wt%), Au (up to 57 ppm), Ag (up to 2010 ppm) and Te (up to 53 ppm) at PACMANUS and SuSu Island arc systems with a submarine expression have a Knolls (Manus Basin; Moss and Scott 2001) have attracted combined length of about 21,700 km (93% in the Pacific attention for potential future submarine mining operations Ocean; de Ronde et al. 2014). Brothers volcano is part of the (Gena 2013). Consequently, it is important to improve our ~ 1200 km long Kermadec island arc, northeast of New Zea- understanding of the ore-forming processes in subduction land (Fig. 1a), which post-dates the earliest phase of Havre zone-related magmatic-hydrothermal systems and to identify Trough back-arc rifting (Wright et al. 1996, 1998). The chemical and mineralogical parameters for exploration and elongated volcanic edifice of Brothers is 13 km long, 8 km their economic evaluation. wide and strikes NW–SE at a water depth of 2200 mbsl (de A key process for the formation of a Cu-rich magmatic- Ronde et al. 2005). The caldera floor (1850 mbsl) has a basal hydrothermal ore deposit is the loss of magmatic volatiles dimension of 3 to 3.5 km and is surrounded by a 350–450 m prior to the formation of immiscible sulphide liquids. In high caldera wall (Fig. 1b; Wright et al. 1998). The caldera contrast, early sulphide segregation, i.e., prior to degassing, hosts a resurgent dome rising to a water depth of 1300 mbsl would extract most chalcophile metals including Cu and at its summit (Fig. 1b; Wright and Gamble 1999; de Ronde Au from the melt leading to a barren arc system (Sun et al. et al. 2001). Hence, at least two stages of magmatic activ- 2004; Jenner et al. 2010; Richards 2011; Park et al. 2015; ity can be distinguished at Brothers volcano including (1) Fontboté et al. 2017). This idea appears to be supported by an effusive incremental caldera-forming eruption (Wright previous studies, which suggest that aqueous S- and Cl-bear- and Gamble 1999) and (2) the subsequent formation of two ing magmatic volatiles are the main source and transport younger volcanic cones (Embley et al. 2012). The Brothers medium for Cu in submarine hydrothermal arc systems, such volcanic rocks range in composition from dacite to rhyolite as Brothers volcano (de Ronde et al. 2005; Berkenbosch (Haase et al. 2006). In addition, one basaltic andesite sample et al. 2012; Gruen et al. 2014). Therefore, economic miner- was recovered from Brothers Ridge, a young SW-NE strik- alisation within an island arc can be controlled by sulphide ing mafic dyke beneath the Brothers caldera (Wysoczanski liquid immiscibility during silicate melt evolution, which is et al. 2012). highly sensitive to changes in pressure, temperature, oxygen Several hydrothermal fields were distinguished includ- fugacity (fO2), the degree of fractional crystallisation and ing hydrothermal venting of evolved seawater derived fluids the initial Fe and S contents of the melt (Mavrogenes and with limited magmatic contribution at the NW caldera wall O’Neill 1999; Jenner et al. 2010; Yang et al. 2014; Keith and magmatic volatile-dominated systems at the Brothers et al. 2017). Arc magmas characteristically show higher fO2 cone complex (Fig. 1b; de Ronde et al. 2005, 2011; Baker (up to FMQ + 2) and H 2O contents (up to 6–8 wt%) and are et al. 2012; Caratori Tontini et al. 2012). Hydrodynamic 1 3 Contributions to Mineralogy and Petrology (2018) 173:40 Page 3 of 16 40 Fig. 1 a Map of the Kermadec island arc showing the location of and upper cone complex. Map modified after Baker et al. (2012). LC Brothers volcano, modified after de Ronde et al.
Load more

Recommended publications
  • A Submarine Magmatic-Hydrothermal System at Brothers Volcano, Kermadecs
    Proceedings 26th NZ Geothermal Workshop 2004 A SUBMARINE MAGMATIC-HYDROTHERMAL SYSTEM AT BROTHERS VOLCANO, KERMADECS A. G. REYES, C.E.J. DE RONDE, AND C. W. R. SOONG Institute of Geological and Nuclear sciences, Lower Hutt, New Zealand SUMMARY –Secondary minerals in dredge samples from the Brothers Volcano include silicates, silica polymorphs; Na-Al, Ca, Ba and Ba-Sr sulphates; Fe, Cu, Zn, As and Pb sulphides; Fe and Mn oxide/oxyhydroxides and native S. The variety and range of mineral compositions indicate deposition in different parts of a submarine hydrothermal system characterised by differences in temperature (ambient seawater to >300oC), fluid compositions, degree of magmatic-hydrothermal water-rock interaction and degree of seawater influence. Secondary minerals originate from a partly exhumed waning hydrothermal system/s (NW caldera); the main upflow of a relatively well-established active magmatic-hydrothermal system on the seafloor where sulphide-rich chimneys are extant (SE caldera) and a nascent magmatic- hydrothermal system where crack zones localise upwelling acid waters from depth (cone). 1. INTRODUCTION possibly two more) of 13 volcanoes (Massoth et al, 2003). The unusually high concentrations of Active seafloor hydrothermal venting and CO2, sulphur gases and Fe in the seafloor vent sulphide deposits were first reported in two discharges are believed to be hybrid mixtures of southern Kermadec frontal arc caldera volcanoes, hydrothermal and magmatic fluids (Massoth et al, Brothers and Rumble II (West), of the Kermadec- 2003). Of the seven hydrothermally active Havre arc-back arc system (Fig. 1) by Wright et al volcanoes, the Brothers volcano is the most (1998). In 1999 a systematic reconnaissance for active, (de Ronde et al, 2003) having two separate submarine hydrothermal activity in the southern vent sites including high-temperature black Kermadec arc found hydrothermal chemical smoker venting (Stoffers et al, 1999).
    [Show full text]
  • Ultra-Long-Range Hydroacoustic Observations of Submarine Volcanic 1
    PUBLICATIONS Geophysical Research Letters RESEARCH LETTER Ultra-long-range hydroacoustic observations 10.1002/2015GL067259 of submarine volcanic activity at Monowai, Key Points: Kermadec Arc • T phase arrivals at Ascension Island can be linked to a submarine eruption D. Metz1, A. B. Watts1, I. Grevemeyer2, M. Rodgers1, and M. Paulatto3 at Monowai, Kermadec Arc • T phases must have traveled along the 1Department of Earth Sciences, University of Oxford, Oxford, UK, 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, SOFAR channel and over a geodesic 3 range of ~15,800 km Germany, Géoazur, Université Nice Sophia Antipolis, Valbonne, France • Our results are confirmed by correlation with broadband seismic data and transmission loss modeling Abstract Monowai is an active submarine volcanic center in the Kermadec Arc, Southwest PacificOcean. During May 2011, it erupted over a period of 5 days, with explosive activity directly linked to the generation Supporting Information: of seismoacoustic T phases. We show, using cross-correlation and time-difference-of-arrival techniques, that • Supporting Information S1 the eruption is detected as far as Ascension Island, equatorial South Atlantic Ocean, where a bottom moored hydrophone array is operated as part of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Correspondence to: Treaty Organization. Hydroacoustic phases from the volcanic center must therefore have propagated through D. Metz, fi [email protected] the Sound Fixing and Ranging channel in the South Paci c and South Atlantic Oceans, a source-receiver distance of ~15,800 km. We believe this to be the furthest documented range of a naturally occurring underwater signal above 1 Hz.
    [Show full text]
  • Interpretation of Detections of Volcanic Activity at Ioto Island Obtained From
    www.nature.com/scientificreports OPEN Interpretation of detections of volcanic activity at Ioto Island obtained from in situ seismometers and remote hydrophones of the International Monitoring System Hiroyuki Matsumoto1,2*, Mario Zampolli2, Georgios Haralabus2, Jerry Stanley2, James Mattila2 & Nurcan Meral Özel2 In-situ seismic observations identifed that volcanic activity of Ioto (formerly Iwojima), a volcanic island ofshore Japan, increased in early September 2018. Observations of discolored nearshore waters and a splash reported by a local fyover provided evidence for a connection between undersea eruptions and recorded seismic activity. However there remain uncertainties as to when the undersea eruption series commenced and how much of the in-situ seismic activity recorded on the island was associated with volcanic earthquakes versus undersea eruptions. During this period, a large number of underwater acoustic (hydroacoustic) signals were recorded by the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) hydroacoustic station HA11, at Wake Island (U.S. Territory), in the northwestern Pacifc Ocean with signals with directions of arrival consistent with sources located at Ioto. The analysis presented here interprets signal features of the remote hydroacoustic recordings provided by HA11 in order to attempt to distinguish between volcanic earthquake signals and undersea eruption signals originating from Ioto. Histograms of hydroacoustic events interpreted as originating from Ioto correlate well with the in-situ seismic observations at Ioto in the early stage of volcanic activity. The results presented suggest that around 75% of the signals detected at HA11 with directions of arrival consistent with Ioto as their origin could be associated with undersea eruptions, supporting the conclusion that the IMS hydroacoustic stations can contribute to volcanic event remote monitoring.
    [Show full text]
  • Tracking Submarine Volcanic Activity at Monowai: Constraints from Long‐Range Hydroacoustic Measurements
    University of South Florida Scholar Commons School of Geosciences Faculty and Staff Publications School of Geosciences 9-2018 Tracking Submarine Volcanic Activity at Monowai: Constraints From Long‐Range Hydroacoustic Measurements D. Metz University of Oxford A. B. Watts University of Oxford I. Grevemeyer GEOMAR Helmholtz Centre for Ocean Research Kiel Mel Rodgers University of South Florida, [email protected] Follow this and additional works at: https://scholarcommons.usf.edu/geo_facpub Part of the Earth Sciences Commons Scholar Commons Citation Metz, D.; Watts, A. B.; Grevemeyer, I.; and Rodgers, Mel, "Tracking Submarine Volcanic Activity at Monowai: Constraints From Long‐Range Hydroacoustic Measurements" (2018). School of Geosciences Faculty and Staff Publications. 2144. https://scholarcommons.usf.edu/geo_facpub/2144 This Article is brought to you for free and open access by the School of Geosciences at Scholar Commons. It has been accepted for inclusion in School of Geosciences Faculty and Staff Publications by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Journal of Geophysical Research: Solid Earth RESEARCH ARTICLE Tracking Submarine Volcanic Activity at Monowai: Constraints 10.1029/2018JB015888 From Long-Range Hydroacoustic Measurements Key Points: D. Metz1,2 , A. B. Watts1 , I. Grevemeyer3 , and M. Rodgers4 • Volcanic activity at Monowai is detected by an IMS hydrophone 1Department of Earth Sciences, University of Oxford, Oxford, UK, 2Research and Development Center for Earthquake and array at Juan Fernández Islands, 3 Southeast Pacific Ocean Tsunami, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan, GEOMAR Helmholtz Centre for 4 • Eighty-two discrete episodes of activity Ocean Research Kiel, Kiel, Germany, School of Geosciences, University of South Florida, Tampa, FL, USA have been identified in a 3.5-year record • Monowai is one of the most active Abstract Monowai is a submarine volcanic center in the Kermadec Arc, Southwest Pacific Ocean.
    [Show full text]
  • Tracking Submarine Volcanic Activity at Monowai: Constraints from Long-Range Hydroacoustic Measurements
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by OceanRep Tracking submarine volcanic activity at Monowai: Constraints from long-range hydroacoustic measurements Authors: D. Metz1*, A. B. Watts1, I. Grevemeyer2, M. Rodgers3 1Department of Earth Sciences, South Parks Road, Oxford OX1 3AN, United Kingdom 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany 3School of Geosciences, University of South Florida, Tampa, Florida, USA * Now at: Research and Development Center for Earthquake and Tsunami, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Kanagawa, Japan Corresponding Author: Dirk Metz ([email protected]) Highlights - Volcanic activity at Monowai is detected by an IMS hydrophone array at Juan Fernández Islands, Southeast Pacific Ocean - 82 discrete episodes of activity have been identified in a 3.5-year record - Monowai is one of the most active submarine arc volcanoes currently known Index Terms: Monowai, submarine volcanism, hydroacoustics, Pacific Ocean, IMS, CTBTO This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1029/2018JB015888 © 2018 American Geophysical Union. All rights reserved. Abstract Monowai is a submarine volcanic center in the Kermadec Arc, Southwest Pacific Ocean. In the past, activity at the volcano had been intermittently observed in the form of fallout at the sea surface, discolored water, changes in seafloor topography, and T phase seismicity, but there is no continuous record for more recent years.
    [Show full text]
  • Cruise Report SONNE 192/2 MANGO
    Schwarz-Schampera, U., Botz, R., Hannington, M., Adamson, R., Anger, V., Cormany, D., Evans, L., Gibson, H., Haase, K., Hirdes, W., Hocking, M., Juniper, K., Langley, S., Leybourne, M., Metaxas, A., Mills, R., Ostertag-Henning, Chr., Rauch, M., Rutkowski, J., Schmidt, M., Shepherd, K., Stevens, C., Tamburri, K., Tracey, D., Westernstroer, U. Cruise Report SONNE 192/2 MANGO Marine Geoscientific Research on Input and Output in the Tonga-Kermadec Subduction Zone Marine Geowissenschaftliche Untersuchungen zum In- und Output der Tonga-Kermadec Subduktionszone Auckland, New Zealand – Suva, Fiji 26 April – 17 May 2007 TABLE OF CONTENTS 1 Summary………………………………………………………………………………. 3 2 Acknowledgements…………………………………………………………………… 8 3 Participants……………………………………………………………………………. 9 4 Cruise Narrative ……………………………………………………………………… 10 5 Structure, Bathymetry and Sampling of the Tonga-Kermadec Arc………............. 15 5.1 Objectives of the Tonga-Kermadec Arc Hydrothermal and Volcanological Program. 15 5.2 Bay of Plenty, Calypso Vent Sites…………………………………………………… 16 5.2.1 Bathymetry and Structure………………………………………………………….. 16 5.2.2 ROPOS Operations………………………………………………………………… 19 5.2.3. Sampling…………………………………………………………………………....24 5.3 Monowai Seamount, Northern Kermadec Arc………………………………………. 26 5.3.1 Bathymetry and Structure………………………………………………………….. 26 5.3.2 ROPOS Operations………………………………………………………………… 30 5.3.3 Sampling…………………………………………………………………………….34 5.4 Volcano U (#21), Northern Kermadec Arc…………………………………………... 37 5.4.1 Bathymetry and Structure…………………………………………………………... 37 5.4.2
    [Show full text]
  • Acoustic Response of Submarine Volcanoes in the Tofua Arc and Northern Lau Basin to Two Great Earthquakes
    Acoustic response of submarine volcanoes in the Tofua Arc and northern Lau Basin to two great earthquakes Bohnenstiehl, D. R., Dziak, R. P., Matsumoto, H., & Conder, J. A. (2013). Acoustic response of submarine volcanoes in the Tofua Arc and northern Lau Basin to two great earthquakes. Geophysical Journal International, 196(3), 1657-1675. doi:10.1093/gji/ggt472 10.1093/gji/ggt472 Oxford University Press Version of Record http://hdl.handle.net/1957/46933 http://cdss.library.oregonstate.edu/sa-termsofuse Geophysical Journal International Geophys. J. Int. (2014) 196, 1657–1675 doi: 10.1093/gji/ggt472 Advance Access publication 2013 December 20 Acoustic response of submarine volcanoes in the Tofua Arc and northern Lau Basin to two great earthquakes DelWayne R. Bohnenstiehl,1 Robert P. Dziak,2 Haru Matsumoto2 and James A. Conder3 1Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27606, USA. E-mail: [email protected] 2Oregon State University and the National Oceanic and Atmospheric Administration, Hatfield Marine Science Center, Newport, OR 97365,USA 3Department of Geology, Southern Illinois University, Carbondale, IL 62901,USA Accepted 2013 November 20. Received 2013 November 19; in original form 2013 June 21 SUMMARY Downloaded from Using a short-baseline hydrophone array, persistent volcanoacoustic sources are identified within the ambient noise field of the Lau Basin during the period between 2009 January and 2010 April. The submarine volcano West Mata and adjacent volcanic terrains, including the northern Matas and Volcano O, are the most active acoustic sources during the 15-month period of observation. Other areas of long-term activity include the Niua hydrothermal field, http://gji.oxfordjournals.org/ the volcanic islands of Hunga Ha’apai, Founalei, Niuatoputapu and Niuafo’ou, two seamounts located along the southern Tofua Arc and at least three unknown sites within the northern Lau Basin.
    [Show full text]
  • Brothers Volcano, Southern Kermadec Arc, New Zealand
    1097-1133 3/31/06 10:38 AM Page 1097 ©2005 Society of Economic Geologists, Inc. Economic Geology, v. 100, pp. 1097–1133 Evolution of a Submarine Magmatic-Hydrothermal System: Brothers Volcano, Southern Kermadec Arc, New Zealand C. E. J. DE RONDE,† Institute of Geological and Nuclear Sciences, P.O. Box 31-312, Lower Hutt, New Zealand M. D. HANNINGTON, Department of Earth Sciences, University of Ottawa, Ottawa, Canada K1N 6N5 P. S TOFFERS, Institute of Geosciences, Christian-Albrechts University of Kiel, Olshausenstrasse 40, 24118 Kiel, Germany I. C. WRIGHT, National Institute of Water and Atmospheric Research, P.O. Box 14-901, Wellington, New Zealand R. G. DITCHBURN, A. G. REYES, Institute of Geological and Nuclear Sciences, P.O. Box 31-312, Lower Hutt, New Zealand E. T. BAKER, Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, 7600 Sand Point Way, NE Bldg. 3, Seattle, Washington 98115-6349 G. J. MASSOTH, Institute of Geological and Nuclear Sciences, P.O. Box 31-312, Lower Hutt, New Zealand J. E. LUPTON, Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, 2115 S.E. OSU Drive, Newport, OR 97365-5258 S. L. WALKER, Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Bldg. 3, Seattle, Washington 98115-6349 R. R. GREENE, Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, 2115 S.E. OSU Drive, Newport, OR 97365-5258 C. W. R. SOONG, Institute of Geological and Nuclear Sciences, P.O. Box 31-312, Lower Hutt, New Zealand J. ISHIBASHI, Faculty of Science, Kyushu University, Japan G.
    [Show full text]
  • Investigating the Geological Evolution of Rumble II West Volcano Using EM300 Bathymetry and Towcam Imagery
    Investigating the geological evolution of Rumble II West Volcano Using EM300 Bathymetry and TowCam Imagery Final Draft – May 28th, 2009 Jennie Mowatt University of Washington School of Oceanography, Box 357940 Seattle, WA 98195-7940 [email protected] Mowatt Non-Technical Summary The Kermadec arc, a hydrothermally active region situated on the boundary of the converging Pacific and Australian plates north of New Zealand, is host to a chain of underwater volcanoes, many of which are both volcanically and hydrothermally active. Rumble II West, located at 35°21.200’S, 178°39.100’E, is one of thirteen volcanoes located on the southern 260 km of the Kermadec arc and before this survey, it had yet to be mapped in detail. Rumble II West is important because it supports rare and unique hydrothermal ecosystems and contributes to deep ocean heat and chemical fluxes. In addition, valuable minerals like sulfides and even gold have been dredged from it. Data was collected aboard the R/V Thompson in March 2009. Bathymetric surveys and camera tows of the seafloor were used to determine the geological evolution of Rumble II West. Results from these analyses indicate that Rumble II West is a post- erupted stratovolcano that has undergone multiple caldera formations and ring faulting. In addition, the volcano has experienced tectonic faulting through the main structure, oriented NE to SW, that demonstrates the buildup of geologic stress created by subduction of the tectonic plates that form the arc. 2 Mowatt Acknowledgements I would like to thank the captain and crew of the R/V Thompson, Dan Fornari, Marshall Swartz, Deb Kelley, Mitch Elend, Mike Reed, Miles Logsdon, Fritz Stahr, and the instructors and my fellow classmates of Ocean 444.
    [Show full text]
  • Proceedings of Kermadec Discoveries and Connections
    Proceedings of Kermadec Discoveries and Connections Science Symposium April 11-12, 2016 Academy Galleries, Queens Wharf, Wellington PROCEEDINGS OF KERMADEC – DISCOVERIES AND CONNECTIONS ISBN: 978-0-473-36137-2 Edited by: Bronwen Golder and Amelia Connell, The Pew Charitable Trusts PO Box 25459 Wellington New Zealand Kermadec – Discoveries and Connections, Wellington, New Zealand, 11-12 April 2016 Suggested citation: Author Name(s). 2016, Article title. In B Golder and A Connell (Eds.) Proceedings of Kermadec – Discoveries and Connections. Paper presented at Kermadec – Discoveries and Connections, Wellington, New Zealand (inclusive page numbers). The Pew Charitable Trusts. The Pew Charitable Trusts is driven by the power of knowledge to solve today’s most challenging problems. Pew applies a rigorous, analytical approach to improve public policy, inform the public, and invigorate civic life. Cover images: ©2016 Jason O’Hara DISCOVERIES AND CONNECTIONS – these are words that excite our imagination and inspire scientific endeavour. The Kermadec region of New Zealand Readers of this Proceedings Document will BRONWEN GOLDER, represents the last frontier in marine and find the descriptors ‘unique’, ‘never before DIRECTOR, KERMADEC island exploration. The near pristine waters seen’, ‘first record’, ‘new species’, and INITIATIVE, GLOBAL OCEAN and island ecology of the Kermadecs offer ‘distinct’ used frequently in the papers LEGACY, THE PEW scientists and conservation agencies a presented – yet further scientific CHARITABLE TRUSTS unique research and management confirmation that the habitats, species and [email protected] opportunity. oceanic processes and connections of the Kermadec region are a globally significant. In 2010 The Pew Charitable Trusts hosted the first ever Kermadec Science Symposium Scientists presenting to the Symposium also - DEEP – Talks and Thoughts Celebrating explored the opportunities for scientific Diversity in New Zealand’s Untouched research that the recently proposed Kermadecs.
    [Show full text]
  • Benthic Community Structure and Environmental Drivers on Monowai Seamount, Kermadec Volcanic Arc
    Benthic community structure and environmental drivers on Monowai Seamount, Kermadec volcanic arc Niharika Dutt Long A thesis submitted for the degree of Master of Science At University of Otago, Dunedin, New Zealand 26 June 2014 ABSTRACT Seamounts are spatially isolated, underwater topographical features that extend more than 1 km above the seafloor. They are products of geological processes, and exhibit diverse forms of venting as a result of volcanism due to plate tectonics. Environmental factors vary greatly on seamounts, due to which they support communities of specialist chemosynthetic invertebrates, suspension-feeding fauna, and large mobile megafauna including many commercially-important fish species. In addition to threats from benthic trawling, seamounts are now viewed as repositories for Seafloor Massive Sulphide (SMS) deposits, owing to their venting activity. The seamounts of the 2500 km-long Tonga-Kermadec volcanic arc are diverse in their hydrothermal activity and, therefore, are potentially of mining interest. Species diversity and abundances differ within and between seamounts of the Kermadec volcanic arc, according to prevailing environmental factors. Three abiotic variables (i.e. water depth, substrate type, proximity to vent sites) were chosen in order to examine their effect on taxa richness, abundances, and benthic community structure for the current study on Monowai Seamount, northern Kermadec volcanic arc. Monowai Caldera was explored as part of the 2005 New Zealand-American Pacific Ring of Fire, using the submersible Pisces V. 4500 still images and 16 hours of video footage for three dives were acquired for recording data on substrate type, water depth, proximity to vent sites, taxa abundance, and composition.
    [Show full text]
  • Detailed Morphology and Structure of an Active Submarine Arc Caldera: Brothers Volcano, Kermadec Arc'
    ©2012 Society of Economic Geologists, Inc. Economic Geology, v. 107, pp. 1557-1570 Detailed Morphology and Structure of an Active Submarine Arc Caldera: Brothers Volcano, Kermadec Arc' R. W. EMBLEY,'J C. E. J. DE RONDE,2 S. G. MERLE,3 B. DAVY,2 AND F. CARATORI TONTINI2 I Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, 2115 SE 0.S. U. Dr., Newport, Oregon 97365-5258 2 GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand 3 Cooperative Institute for Marine Resources Studies, Oregon State University, 2115 SE 0.S. U. Dr., Newport, Oregon 97365-5258 Abstract A survey of the Brothers caldera volcano (Kermadec arc) with the autonomous underwater vehicle ABE has revealed new details of the morphology and structure of this submarine frontal arc caldera and the geologic setting of its hydrothermal activity. Brothers volcano has formed between major SW-NE-trending faults within the extensional field of the Havre Trough. Brothers may be unique among known submarine calderas in that it has four active hydrothermal systems, two high-temperature sulfide-depositing sites associated with faulting on the northwestern and western walls (i.e., the NW caldera and W caldera hydrothermal sites, respectively), and gas-rich sites on the summits of the constructional cones that fill most of the southern part of the caldera (i.e., the Upper and Lower cone sites). The 3.0- x 3.4-km caldera is well defined by a topographic rim encompassing -320° of its circumference and which lies between the bounds of two outer half-graben-shaped faults in the northwest and southeast sectors.
    [Show full text]