 | | Journal (article/letter/editorial) | | Plagioclase-wehrlites and peridotites on the East Pacific Rise (Hess Deep) and the Mid-Atlantic Ridge (DSDP Site...The samples studied come from the East Pacific Rise (EPR) (Hess Deep) and the Mid-Atlantic Ridge (MAR)...for olivine suggest a magmatic origin for the Hess Deep wehrlite. Its phase chemistry is comparable to...mush. It differs drastically from the associated Hess Deep diopside-bearing harzburgites and dunites, which...plagioclase-wehrlites studied came from the Hess Deep in the Equatorial Pacific [31], and they are presented together |  | | Journal (article/letter/editorial) | | in lower oceanic crustal troctolites from the Hess Deep Rift Toshio Nozaka1 · Romain Meyer2,4 · Robert...troctolites recovered from IODP Site U1415 at the Hess Deep Rift. The spinel is green-colored, has an irregular...of knowledge, Expedition 345 of the Integrated Ocean Drilling Program (IODP) was designed to drill and...level oceanic crustal rocks formed at the East Pacific Rise (EPR) with the principal objectives to understand...for their formation. Geological setting At the Hess Deep Rift, young plutonic crust formed at the fast-spreading |  | | Journal (article/letter/editorial) | | Montpellier, France Abstract It has been proposed that deep, high-T (up to 1000°C) hydrothermal alteration occurred...the paleo-ridge axis in the Oman ophiolite. In the deep, hot gabbros, the main water channels are submillimetric...close to the ridge axis. Since the first record of deep and high temperature hydrothermal alteration in...strontium and oxygen isotope tracing, the possibility of deep penetration of seawater close to the axis of fast...One reason was the difficulty of integrating such deep circulation in the framework of the wing-shaped |  | | Journal (article/letter/editorial) | | association in the Garrett Transform, * 13”28’S, East Pacific Rise CEPR), provides a prime opportunity for examining...peridotites from elsewhere at the EPR (i.e., Hess Deep and the Terevaka Transform) also are similarly...Azores hotspot in the Atlantic Ocean and Bouvet hotspot in the Indian Ocean), and is significantly higher...be the average extent of melting beneath global ocean ridges. Many of these harzburgite samples, however...also have various amounts of excess olivine with forsterite contents as low as Fo,. The total olivine modes |  | | Journal (article/letter/editorial) | | Podiform chromitites do form beneath mid-ocean ridges Shoji Arai, Makoto Miura PII: DOI: Reference:...Makoto, Podiform chromitites do form beneath mid-ocean ridges, LITHOS (2015), doi: 10.1016/j.lithos.2015...MANUSCRIPT Podiform chromitites do form beneath mid-ocean ridges PT Shoji Arai* and Makoto Miura SC RI...have AC rarely been observed in the present-day ocean floor, even though some ophiolites are considered...apparent rarity of chromitites in the present-day ocean floor is SC RI simply a reflection of the under-sampling |  | | Journal (article/letter/editorial) | | crystallization of new plagioclase and diopside by a mid-ocean ridge basalt (MORB)-like melt, producing a high-Mg...content with respect to diopside Mg# and olivine forsterite content. Contrasting olivine nickel contents...troctolites and gabbros bear clear similarities to East Pacific Rise (EPR) troctolites and gabbroic segregations...dunites crosscutting residual mantle peridotite at Hess Deep Site 895. The latter represent multi-stage crystallization...that formed the Godzilla troctolites occur beneath ocean ridges across the spreading rate spectrum. KEY |  | | Journal (article/letter/editorial) | | olivine in troctolites and olivine gabbros from the Hess Deep Rift Toshio Nozaka, Robert P. Wintsch, Romain...olivine in troctolites and olivine gabbros from the Hess Deep Rift, LITHOS (2017), doi:10.1016/j.lithos.2016...olivine in troctolites and olivine gabbros from the Hess Deep Rift 1 SC R IP T Toshio Nozaka1*, Robert...gabbroic rocks recovered from IODP Site U1415 at the Hess Deep Rift were examined and compared NU with peridotites...variable degree of serpentinization are essential, and ocean-floor drilling provides an opportunity to observe |  | | Journal (article/letter/editorial) | | heterogeneities among the magmas parental to mid-ocean ridge basalts (MORB) was investigated using a single...of petrological and geochemical studies on mid-ocean ridge basalts (MORB), their cumulative counterparts...and anomalous compositions among MORB solely due deep-seated processes is often challenged by research...phosphorus-rich compositions within group-II. Fo_Ol mol% forsterite in host olivine, CaO_Ol wt% CaO content in host...high-Ti spinel trapped in low-Ca olivine. Fo mol% forsterite in olivine, Mg#sp spinel mg-number, 100 · Mg/ |  | Perk, Neil W., Coogan, Laurence A., Karson, Jeffrey A., Klein, Emily M., Hanna, Heather D. (2007) Petrology and geochemistry of primitive lower oceanic crust from Pito Deep: implications for the accretion of the lower crust at the Southern East Pacific Rise. Contributions to Mineralogy and Petrology, 154 (5) 575-590 doi:10.1007/s00410-007-0210-z | Journal (article/letter/editorial) | | Pito Deep: implications for the accretion of the lower crust at the Southern East Pacific Rise Neil W...crust formed at the southern East Pacific Rise and exposed at the Pito Deep has been examined. These rocks...the Hess Deep) in which a substantial depth into the plutonic complex formed at the East Pacific Rise...rocks at Hess Deep, the rocks studied here are generally primitive with olivine forsterite contents mainly...samples crystallized from was aggregated normal mid-ocean ridge basalt (MORB). Despite this high Mg# clinopyroxene |  | | Journal (article/letter/editorial) | | evolution inthe shallow mantle beneath the East Pacific Rise: preliminary results from ODP site 895 H.J...Rosenstiel School of Marine and Atmospheric Sciences. Ocean Drilling Program, Texas A&M Univ. College Station...locations 250 metres apart on the intrarift high at Hess Deep where the amagmatic tip of the westward propagating...Party, 1993). The latter are parallel to the East Pacific Rise when reoriented using down hole logs and paleomagnetic...3.6 CPX and 0.5 SP). Chemically, however, the Hess Deep harzburgites have 50% less alumina, and lower |  | | Journal (article/letter/editorial) | | shallow mantle at the East Pacific Rise: evidence from ODP Site 895 (Hess Deep) STEPHEN J. EDWARDS Department... Abstract Ocean Drilling Program (ODP) Leg 147 recently drilled at Site 895 in Hess Deep (eastern Equatorial...Equatorial Pacific), where a structurally dissected section of the East Pacific Rise (EPR) is preserved...mantle melting than normally expected below mid-ocean ridges. Subsequently, basaltic melt(s) interacted...harzburgite, mid-ocean ridge basalt, melt-peridotite interaction, mantle refertilization, Hess Deep, East Pacific |  | | Journal (article/letter/editorial) | | crystal mush-dominated magma plumbing system: a mid-ocean ridge perspective Research C. Johan Lissenberg...crystal mush-dominated magma plumbing system: a mid-ocean ridge perspective. Phil. Trans. R. Soc. A 377: 20180014...volcanology Keywords: crystal mush, mid-ocean ridge, magma chamber, mid-ocean ridge basalt Author for correspondence:...6084/m9. figshare.c.4302707. School of Earth and Ocean Sciences, Cardiff University, Park Place, Cardiff...paradigm for the evolution of igneous systems. Mid-ocean ridges provide a unique opportunity to study mush |  | | Journal (article/letter/editorial) | | hydrothermal; cooling; crust 1. Introduction Mid-ocean ridges serve as the primary locus for heat and mass...ophiolite (Fig. 2) is the best analogue for a paleo-mid ocean ridge because dikes and lavas have a trace element...at the base of the sheeted dikes along the East Pacific Rise (EPR) J.A. VanTongeren et al. / Earth and...a wide range of temperature (1500–900 °C) and forsterite content (Fo100–Fo83). 3.4.2. Dependence of calcium...calcium diffusivity on olivine forsterite content It has been proposed that increased Fe concentration |  | Matsukage, K. N., Kikuchi, S., Ono, S., Nishihara, Y., Kikegawa, T. (2010) Density and seismic velocities of chromitite body in oceanic mantle peridotite. American Mineralogist, 95 (10) 1422-1428 doi:10.2138/am.2010.3498 | Journal (article/letter/editorial) | | Oman ophiolite was formed at a fast-spreading mid-ocean ridge system (e.g., Nicolas 1989). On the other...ophiolite and concluded that one was formed at a mid-ocean ridge and the other was formed at a subduction zone...2010.3498 oceanic peridotites from mid-ocean ridges and ocean floors, except for one rod-shaped mini-chromitite...about 2 cm across and 10 cm long from Hess Deep, East Pacific Rise (Arai and Matsukage 1996; Matsukage...formed at a mid-ocean ridge, we can find the chromitite at present mid-ocean ridges and/or ocean floor regions |  | | Journal (article/letter/editorial) | | Oman ophiolite; Clinopyroxene; Trace elements; Mid-ocean ridges; Gabbros 1. Introduction Ophiolites have...ridges (e.g. [1,2]). However, coexistence of mid-ocean ridge basalt (MORB)-type extrusives and extrusive...08.027 ophiolite complex were not formed at mid-ocean ridges [3–6]. While such arc-like extrusive rocks...compositional ranges of DW and GB2. Data sources: East Pacific Rise [29,30]; Mid-Atlantic Ridge DSDP Site 334...is very similar to that of Hess Deep gabbros formed at East Pacific Rise (EPR [29,30]), indicating no |  | Sanfilippo, Alessio, Morishita, Tomoaki, Kumagai, Hidenori, Nakamura, Kentaro, Okino, Kyoko, Hara, Kaori, Tamura, Akihiro, Arai, Shoji (2015) Hybrid troctolites from mid-ocean ridges: inherited mantle in the lower crust. Lithos, 232. 124-130 doi:10.1016/j.lithos.2015.06.025 | Journal (article/letter/editorial) | | Hybrid troctolites from Mid-Ocean Ridges: Inherited mantle in the lower crust Alessio...Akihiro, Arai, Shoji, Hybrid troctolites from Mid-Ocean Ridges: Inherited mantle in the lower crust, LITHOS... ACCEPTED MANUSCRIPT Hybrid troctolites from Mid-Ocean Ridges: inherited mantle in the lower crust PT...nearly all the plutonic sample suites from mid-ocean ridges (e.g. Elthon 1987; Dick and Natland, 1996;...constitute the lowermost crustal sector of Hess Deep in the Pacific Ocean (Gillis et al., 2014) and occur in |  | Tseng, C.-Y., Yang, H.-Y., Wu, H.-Q., Zuo, G.-C. (2007) THE SILICATE MINERAL INCLUSIONS IN THE CHROMIAN SPINEL FROM THE DONGCAOHE OPHIOLITE, NORTH QILIAN MOUNTAINS, NORTHWESTERN CHINA: RECORD OF SYNTEXIS OF LOWER OCEANIC CRUST. The Canadian Mineralogist, 45 (4) 793-808 doi:10.2113/gscanmin.45.4.793 | Journal (article/letter/editorial) | | The Dongcaohe ophiolite, a typical Caledonian mid-ocean-ridge type of ophiolite with an age of 497 ± 7 Ma... It is interpreted to have originated in a mid-ocean ridge or mature back-arc environment on the basis...1991), Hess Deep (Arai & Matsukage 1998), Oman ophiolite (Arai et al. 2004), Mid-Cayman Rise (Elthon...crystallized or precipitated. On the other hand, if forsterite and melt with a low solid-to-melt ratio were...1974), the reaction between them would exhaust forsterite and produce aspidolite and a Na-rich residual |  | | Journal (article/letter/editorial) | | Saunders b, R.N. Wilson b a b School of Earth and Ocean Sciences, Bob Wright Building, University of Victoria...temperatures of up to 1270 °C (and a maximum olivine forsterite (Fo) content of Fo91.3) consistent with previous...constraints (e.g. from the volume of melt produced at mid-ocean ridges). Substantially higher crystallization temperatures...picrites from Baffin Island (up to 1408 °C; Fo91.3) and East Greenland (up to 1354 °C; Fo90.1), Cretaceous (86...http://dx.doi.org/10.1016/j.chemgeo.2014.01.004 mid-ocean ridge (MOR) system due to plate spreading and nearadiabatic |  | | Journal (article/letter/editorial) | | ultramafic rocks from the Garrett transform fault (East Pacific Rise) Mathilde C a n n a t a, Daniel Bideau b and...of deformed ultramafic rocks at the end of their deep-seated plastic deformation. This melt crystallized...of samples may represent fragments of the East Pacific Rise crust-mantle transition zone. The deformed...1980 Geometep (Geothermal Metallogenesis in the East Pacific) cruise of the R.V. Sonne (Preussag, F.R.G.)...transform fault offsets two fast-spreading East Pacific Rise segments (total spreading rate about 17 cm/yr; |  | | Journal (article/letter/editorial) | | apparent difference in oxygen isotope compositions of ocean crusts formed with different spreading rates has...has important implications on the buffering of ocean water over geological time, as well as on the oxygen...Geology 233 (2006) 217–234 reactions in the upper ocean crust have the largest effects on the net chemical...and crust, crust–seawater reactions in the lower ocean crust are also critical for global geochemical budgets...1998, 2000; Eiler, 2001). The 18O composition of ocean water results mainly from the balance of two independent |  | Python, Marie, Ceuleneer, Georges, Ishida, Yoshito, Barrat, Jean-Alix, Arai, Shoji (2007) Oman diopsidites: a new lithology diagnostic of very high temperature hydrothermal circulation in mantle peridotite below oceanic spreading centres. Earth and Planetary Science Letters, 255 (3) 289-305 doi:10.1016/j.epsl.2006.12.030 | Journal (article/letter/editorial) | | anorthite (An% up to 0.99), minor amounts of forsterite (Fo N 0.95) or traces of andradite. When not...setting of the Oman ophiolite is still debated (ocean ridge, (e.g. [20–22]) versus arc-related basin,...where basaltic MORBlike magmas are emplaced on a deep seafloor in an extensional environment. The upper...is associated in a few samples to anorthite, forsterite or to andradite and/or to more or less abundant...phases constituting the “diopsidite”: diopside, forsterite and anorthite. Other phases like andradite, antigorite |  | | Journal (article/letter/editorial) | | fast-spreading lower oceanic crust (Hess Deep, equatorial Pacific Ocean) C. Johan Lissenberg a,n, Christopher...a, Marguerite Godard b a b School of Earth and Ocean Sciences, Cardiff University, Park Place, Cardiff... Elliott Available online 7 December 2012 Mid-ocean ridge basalt (MORB) is the most abundant magma on...fast-spread lower crustal rocks exposed in Hess Deep (equatorial Pacific Ocean) demonstrate that their evolution... Keywords: mid-ocean ridge basalt lower oceanic crust reactive porous flow Hess Deep 1. Introduction |  | Zawadzki, Dominik, Maciąg, Łukasz, Blasco, Iker, González, Francisco Javier, Wernette, Benjamin, Marino, Egidio, Kozub-Budzyń, Gabriela A., Piestrzyński, Adam, Wróbel, Rafał J., McCartney, Kevin (2022) Geochemistry and Mineralogy of Ferromanganese Crusts from the Western Cocos-Nazca Spreading Centre, Pacific. Minerals, 12 (5) 538 doi:10.3390/min12050538 | Journal (article/letter/editorial) | | from the Western Cocos-Nazca Spreading Centre, Pacific ˛ 1 , Iker Blasco 2 , Francisco Javier González...from the Western Cocos-Nazca Spreading Centre, Pacific. Minerals 2022, 12, 538. https://doi.org/10.3390/...es (F.J.G.); e.marino@igme.es (E.M.) Earth and Ocean Sciences, Duke University, 9 Circuit Drive, Durham...that elucidate the geochemistry and mineralogy of a deep-sea geological setting. Six representative Fe-Mn...of crusts from the South China Sea, Western Pacific Ocean and Canary Island Seamount Province note that |  | | Journal (article/letter/editorial) | | fundamental processes during the generation of ocean crust at slow-spreading midocean ridges, where large...Serpentinization also occurs in unexposed peridotites along deep faults at slow-spreading ridges (Bougault et al...into the peridotites in the southern MARK area on Ocean Drilling Program (ODP) Leg 153 (Fig. 1). Hole 920B...Vienna Peedee belemnite and Vienna standard mean ocean water for carbon and oxygen, respectively. Reproducibility...and forsterite in 1:5 mass ratio. The lack of solid solutions limited the model because forsterite and |  | | Journal (article/letter/editorial) | | minor and trace element analyses of olivine (forsterite = 84–82 mol%) were carried out. Olivine from...element compositions are also shown by olivine (forsterite = 86 mol%) from a clinopyroxene-rich troctolite...(this study) are also reported. c Variation in forsterite component (mol%) in olivine as a function of...Olivine and plagioclase from the Ol-gabbros have forsterite (Fo) and anorthite (An) component in the ranges...from the three rock types correlate with the forsterite component; olivine from the dunites has the highest |
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