Matches in SemOpenAlex for { <https://semopenalex.org/work/W2964953477> ?p ?o ?g. }
- W2964953477 endingPage "896" @default.
- W2964953477 startingPage "857" @default.
- W2964953477 abstract "Abstract Tinakula is the first seafloor massive sulfide deposit described in the Jean Charcot troughs and is the first such deposit described in the Solomon Islands—on land or the seabed. The deposit is hosted by mafic (basaltic-andesitic) volcaniclastic rocks within a series of cinder cones along a single eruptive fissure. Extensive mapping and sampling by remotely operated vehicle, together with shallow drilling, provide insights into deposit geology and especially hydrothermal processes operating in the shallow subsurface. On the seafloor, mostly inactive chimneys and mounds cover an area of ~77,000 m2 and are partially buried by volcaniclastic sand. Mineralization is characterized by abundant barite- and sulfide-rich chimneys that formed by low-temperature (<250°C) venting over ~5,600 years. Barite-rich samples have high SiO2, Pb, and Hg contents; the sulfide chimneys are dominated by low-Fe sphalerite and are high in Cd, Ge, Sb, and Ag. Few high-temperature chimneys, including zoned chalcopyrite-sphalerite samples and rare massive chalcopyrite, are rich in As, Mo, In, and Au (up to 9.26 ppm), locally as visible gold. Below the seafloor, the mineralization includes buried intervals of sulfide-rich talus with disseminated sulfides in volcaniclastic rocks consisting mainly of lapillistone with minor tuffaceous beds and autobreccias. The volcaniclastic rocks are intensely altered and variably cemented by anhydrite with crosscutting sulfate (± minor sulfide) veins. Fluid inclusions in anhydrite and sphalerite from the footwall (to 19.3 m below seafloor; m b.s.f.) have trapping temperatures of up to 298°C with salinities close to, but slightly higher than, that of seawater (2.8–4.5 wt % NaCl equiv). These temperatures are 10° to 20°C lower than the minimum temperature of boiling at this depth (1,070–1,204 m below sea level; m b.s.l.), suggesting that the highest-temperature fluids boiled below the seafloor. The alteration is distributed in broadly conformable zones, expressed in order of increasing depth and temperature as (1) montmorillonite/nontronite, (2) nontronite + corrensite, (3) illite/smectite + pyrite, (4) illite/smectite + chamosite, and (5) chamosite + corrensite. Zones of argillic alteration are distinguished from chloritic alteration by large positive mass changes in K2O (enriched in illite/smectite), MgO (enriched in chamosite and corrensite), and Fe2O3 (enriched in pyrite associated with illite/smectite alteration). The δ18O and δD values of clay minerals confirm increasing temperature with depth, from 124° to 256°C, and interaction with seawater-dominated hydrothermal fluids at high water/rock ratios. Leaching of the volcanic host rocks and thermochemical reduction of seawater sulfate are the primary sources of sulfur, with δ34S values of sulfides, from –0.8 to 3.4‰, and those of sulfate minerals close to seawater sulfate, from 19.3 to 22.5‰. The mineralization and alteration at Tinakula are typical of a class of ancient massive sulfide deposits hosted mainly by permeable volcaniclastic rocks with broad, semiconformable alteration zones. Processes by which these deposits form have never been documented in modern seafloor massive sulfide systems, because they mostly develop below the seafloor. Our study shows how hydrothermal fluids can become focused within permeable rocks by progressive, low-temperature fluid circulation, leading to a large area (>150,000 m2) of alteration with reduced permeability close to the seafloor. In our model, overpressuring and fracturing of the sulfate- and clay-cemented volcaniclastic rocks produced the pathways for higher-temperature fluids to reach the seafloor, present now as sulfate-sulfide veins within the footwall. In the geologic record, the sulfate (anhydrite) is not preserved, leaving a broad zone of intense alteration with disseminated and stringer sulfides typical of this class of deposits." @default.
- W2964953477 created "2019-08-13" @default.
- W2964953477 creator A5013157752 @default.
- W2964953477 creator A5014486346 @default.
- W2964953477 creator A5023273464 @default.
- W2964953477 creator A5023848976 @default.
- W2964953477 creator A5026927544 @default.
- W2964953477 creator A5040070643 @default.
- W2964953477 creator A5051390784 @default.
- W2964953477 creator A5051589213 @default.
- W2964953477 creator A5091277103 @default.
- W2964953477 date "2019-08-01" @default.
- W2964953477 modified "2023-10-18" @default.
- W2964953477 title "Mineralization and Alteration of a Modern Seafloor Massive Sulfide Deposit Hosted in Mafic Volcaniclastic Rocks" @default.
- W2964953477 cites W1104249897 @default.
- W2964953477 cites W1500521030 @default.
- W2964953477 cites W1580005852 @default.
- W2964953477 cites W1829409607 @default.
- W2964953477 cites W1966533481 @default.
- W2964953477 cites W1967782998 @default.
- W2964953477 cites W1970620897 @default.
- W2964953477 cites W1970688872 @default.
- W2964953477 cites W1972289882 @default.
- W2964953477 cites W1972576751 @default.
- W2964953477 cites W1976925845 @default.
- W2964953477 cites W1978103525 @default.
- W2964953477 cites W1978575630 @default.
- W2964953477 cites W1980279852 @default.
- W2964953477 cites W1987893812 @default.
- W2964953477 cites W1990648220 @default.
- W2964953477 cites W1996353541 @default.
- W2964953477 cites W1999510688 @default.
- W2964953477 cites W2007766604 @default.
- W2964953477 cites W2009411381 @default.
- W2964953477 cites W2010362138 @default.
- W2964953477 cites W2012332079 @default.
- W2964953477 cites W2012371198 @default.
- W2964953477 cites W2015233306 @default.
- W2964953477 cites W2015380516 @default.
- W2964953477 cites W2016383875 @default.
- W2964953477 cites W2017019550 @default.
- W2964953477 cites W2019292242 @default.
- W2964953477 cites W2021239497 @default.
- W2964953477 cites W2024423764 @default.
- W2964953477 cites W2024745768 @default.
- W2964953477 cites W2028391171 @default.
- W2964953477 cites W2029095556 @default.
- W2964953477 cites W2030425270 @default.
- W2964953477 cites W2038614693 @default.
- W2964953477 cites W2040601871 @default.
- W2964953477 cites W2041908627 @default.
- W2964953477 cites W2042659773 @default.
- W2964953477 cites W2045469782 @default.
- W2964953477 cites W2047018904 @default.
- W2964953477 cites W2057129180 @default.
- W2964953477 cites W2057359362 @default.
- W2964953477 cites W2058173185 @default.
- W2964953477 cites W2059927840 @default.
- W2964953477 cites W2061180928 @default.
- W2964953477 cites W2068202901 @default.
- W2964953477 cites W2070387486 @default.
- W2964953477 cites W2070577207 @default.
- W2964953477 cites W2073250859 @default.
- W2964953477 cites W2074139688 @default.
- W2964953477 cites W2078066621 @default.
- W2964953477 cites W2085190551 @default.
- W2964953477 cites W2087251279 @default.
- W2964953477 cites W2103925461 @default.
- W2964953477 cites W2111020458 @default.
- W2964953477 cites W2112677651 @default.
- W2964953477 cites W2113926304 @default.
- W2964953477 cites W2128269348 @default.
- W2964953477 cites W2128430996 @default.
- W2964953477 cites W2131535386 @default.
- W2964953477 cites W2132280939 @default.
- W2964953477 cites W2140763040 @default.
- W2964953477 cites W2148144387 @default.
- W2964953477 cites W2149572008 @default.
- W2964953477 cites W2160704711 @default.
- W2964953477 cites W2168167187 @default.
- W2964953477 cites W2169746538 @default.
- W2964953477 cites W2171200618 @default.
- W2964953477 cites W2189032598 @default.
- W2964953477 cites W2204644854 @default.
- W2964953477 cites W2273854651 @default.
- W2964953477 cites W2276480568 @default.
- W2964953477 cites W2315728977 @default.
- W2964953477 cites W2325880464 @default.
- W2964953477 cites W2620625402 @default.
- W2964953477 doi "https://doi.org/10.5382/econgeo.4666" @default.
- W2964953477 hasPublicationYear "2019" @default.
- W2964953477 type Work @default.
- W2964953477 sameAs 2964953477 @default.
- W2964953477 citedByCount "26" @default.
- W2964953477 countsByYear W29649534772020 @default.
- W2964953477 countsByYear W29649534772021 @default.
- W2964953477 countsByYear W29649534772022 @default.
- W2964953477 countsByYear W29649534772023 @default.