 | | Report (chapter) | | Sr-isotopic constraints from D S D P ] O D P Holes 504B and 896A D. A. H . T E A G L E , J. C. A L T & A...ODP Holes 504B and 896A have been compiled into a profile for the upper 2 km of in situ ocean crust to...This elevated signature reflects the 87Sr/S6Sr of 504B black smoker-type fluids and requires less fluid...controlled by hydrothermal interactions with the ocean floor, yet the detailed mechanisms and transport...characterised strontium isotopic compositions of ocean ridge basalts (87Sr/ 86Sr~0.7025) and seawater (87Sr/ |  | | Report (chapter) | | intermediate-spread oceanic crust drilled at DSDP/ODP Holes 504B and 896A, Costa Rica Rift YILDIRIM DILEK Department... USA Abstract: Deep Sea Drilling Project/Ocean Drilling Program (DSDP/ODP) Hole 504B, situated on the...intermediate-spreading Costa Rica Rift in the eastern equatorial Pacific, penetrates 2.1 km into 5.9 Ma old oceanic crust...oceanic lithosphere. Hole 896A, located on a basement high nearly 1 km south of Hole 504B, penetrates 290...the upper volcanic sequence, and together with Hole 504B provides an opportunity to examine variations |  | | Journal (article/letter/editorial) | | Phyllosilieates in hydrothermally altered basalts from DSDP Hole 504B, Leg 8 3 - a TEM and AEM study* Yen-Hong Shau**...fracture-fillings in hydrothermally altered basalts from DSDP Hole 504B, Leg 83 have been studied using transmission and...levels of the sheeted dike zone. Chlorite, talc, and mixed-layer talc/chlorite are the major phyllosilicates...in the sheeted dike zone, although replacement of talc or olivine by saponite is observed. The phyllosilicates...corrensite and talc, indicating poorer crystallinity of saponite. By contrast, chlorite and talc from the lower |  | | Journal (article/letter/editorial) | | hydrothermally altered and weathered rocks in DSDP Hole 504B, Costa Rica Rift H o d a k a Kawahata ~'*, Minoru...1986; revised version received July 8, 1987 DSDP Hole 504B was drilled into 6 Ma crust, about 200 km south...relation to the alteration zones are recorded in Hole 504B, as follows: Zone Depth (m) Average 878r/86...hydrothermal springs on the Galapagos Rift and the East Pacific Rise at 21°N, the surface geology along rift valleys...m e a s u r e m e n t s (e.g. [ 6 - 1 1 ] ) . Hole 504B provides an excellent opportunity to investigate |  | | Report (chapter) | | alteration in the volcanic section of DSDP/ODP Hole 504B. The studied crustal section (from top of the...the basement to 1000 mbsf (metres below sea floor)) consists of low resistivity/ high porosity pillow lavas...contrasting permeability. Hole 504B (Costa Rica Rift, Pacific Ocean) is the only bore-hole to penetrate the oceanic...oceanic crust. Drilling operations during seven DSDP/ODP cruises devoted to deepening Hole 504B attained an...in the uppermost volcanic section of DSDP/ODP Hole 504B, down to a depth of 1000 mbsf. By using a multi-scalar |  | | Report (chapter) | | University o f Leeds, Leeds L S 2 9JT, U K 2 c/o Ocean Drilling Program, Texas A & M University, 1000 Discovery...low temperature hydrothermal alteration of the ocean crust, ODP Leg 168 drilled a series of holes across...168 In: MILLS,R. A. • HARRISON,K. (eds) Modern Ocean Floor Processes and the Geological Record, Geological...rate (Davis et al., 1997). Previous sea-surface and shallow drilling expeditions (Davis et al. 1992; Wheat...eastern flank of the Juan de Fuca Ridge, NE Pacific Ocean; Downloaded from http://sp.lyellcollection |  | | Journal (article/letter/editorial) | | crust Kathryn M. Gillis ’ Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA Received 21 November...sections that formed at the fast-spreading East Pacific Rise (EPR) were mapped by submersible along steep...steep fault scarps that bound the Hess Deep rift valley. Excellent exposures allowed the documentation...formed at mid-ocean ridges with slower rates of spreading than the EPR are similar to Hess Deep, although...Introduction Field programs along the northern East Pacific Rise CEPR) have provided a wealth of new infortna1 |  | | Journal (article/letter/editorial) | | Amsterdam - - Printed in The Netherlands 259 SUB-SEA-FLOOR HYDROTHERMAL ALTERATION IN THE GAI.fi, PAGOS...SPREADING CENTER HODAKA KAWAHATA* and TOSHIO FURUTA Ocean Research Institute, University of Tokyo, Tokyo 164...Abstract Kawahata, H. and Furuta, T., 1985. Sub-sea floor hydrothermal alteration in the Gal~pagos Spreading..., 49: 259--274. Oceanic crust was drilled at Hole 504B on the southern crest of Costa Rica Rift, Gal~pagos...Gal~pagos Spreading Center. This is the first hole that contains hydrothermally altered rocks containing |  | | Journal (article/letter/editorial) | | the effects of hydrothermal interaction at mid-ocean ridge axes are extremely important, theoretical...shown that mid-ocean ridge flanks lose more than three times as much heat as active mid-ocean ridge axes...line. and the eastern flank of the JdFR, NE Pacific Ocean. ŽAdapted from Davis et al., 1997. A.G. Hunter...of the crust obtained during ODP Leg 168. 5 6 Hole Location Transect 1023A 47855.04 N 128847.53... 47845.39 N 128843.87 W a mbsf s metres below sea floor. HT: Hydrothermal Transect. BB: Buried Basement |  | | Journal (article/letter/editorial) | | Trinity basalts are larger than those from Hole 504B and East Pacific Rise ( ~ 1.5). This is a possible consequence...center generating a thin crust. Contrasting with Hole 504B, this hydrothermal pattern is likely able to equilibrate...seawater. Hydrothermal activity wellknown in mid-ocean ridges (Edmond et al., 1979) has also been recently...dike levels sampled at the Deep Sea Drilling Project ( D S D P ) Hole 504B (Staudigel and Hart, 1983;...remnants of oceanic crust whether formed at mid-ocean ridges or in marginal basins (Dewey and Bird, 1971; |  | Shibuya, Takazo, Komiya, Tsuyoshi, Anma, Ryo, Ota, Tsutomu, Omori, Soichi, Kon, Yoshiaki, Yamamoto, Shinji, Maruyama, Shigenori (2007) Progressive metamorphism of the Taitao ophiolite; evidence for axial and off-axis hydrothermal alterations. Lithos, 98 (1) 233-260 doi:10.1016/j.lithos.2007.04.003 | Journal (article/letter/editorial) | | was due to axial hydrothermal alteration at a mid-ocean ridge. Mineral assemblages and the compositions...Comparison between the Taitao ophiolite with its mid-ocean ridge (MOR) affinity, and other ophiolites and MOR...Ophiolite; Hydrothermal metamorphism; Taitao; Mid-ocean ridge system 1. Introduction ⁎ Corresponding author...reserved. doi:10.1016/j.lithos.2007.04.003 Mid-ocean ridges are places where interactions between seawater...diverse biological communities in otherwise barren ocean floor settings, and are candidates for the birthplace |  | | Journal (article/letter/editorial) | | section of dikes in the oceanic crust, DSDPrODP Hole 504B Christine Laverne a,) , Pierre Agrinier b, Daniel...high-level dike section of DSDPrODP 504B which was drilled in 1981. Hole 504B is the only place where a continuous...considering the entire dike section penetrated by Hole 504B is a unique chance to study chemical fluxes related...compositions of glasses Žs P1a. or basalts from the Hole 504B volcanics have been used as protoliths. In this...of various protoliths based on dolerites from Hole 504B. We show that the most adequate and realistic |  | | Journal (article/letter/editorial) | | greenstones from two other locations, i.e. DSDP Hole 504B and Galfipagos Rift near 86°W, we suggest that...Departmentof Marine Chemistry and Geochemistry,Woods Hole, MA 02543-1541, USA. * 0009-2541/97/$17.00 Copyright...suggested to be the source for HIMU (high 238U//2°4pb) ocean island basalts (Hofmann, 1988; Chauvel et al., 1992)...are then remobilised during subduction) near the ocean ridges (Peucker-Ehrenbrink et al., 1994). A mechanism...Geological setting and sampling The Chile Ridge (SE Pacific) forms the boundary between the Nazca Plate to |  | Bach, Wolfgang, Alt, Jeffrey C., Niu, Yaoling, Humphris, Susan E., Erzinger, Jörg, Dick, Henry J.B. (2001) The geochemical consequences of late-stage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735B (Leg 176) Geochimica et Cosmochimica Acta, 65 (19) 3267-3287 doi:10.1016/s0016-7037(01)00677-9 | Journal (article/letter/editorial) | | low-grade alteration of lower ocean crust at the SW Indian Ridge: Results from ODP Hole 735B (Leg 176) WOLFGANG...Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA 5 GeoForschungsZentrum...budgets for chemical flux in the flanks of mid-ocean ridges have only considered exchange between basalt...up a significant fraction of sea floor produced at the global mid-ocean ridge system. Moreover, the rugged...ridge flanks are more rapidly isolated from the ocean by a sediment seal. Hence, elemental fluxes during |  | Nimis, Paolo, Tesalina, Svetlana G., Omenetto, Paolo, Tartarotti, Paola, Lerouge, Catherine (2004) Phyllosilicate minerals in the hydrothermal mafic?ultramafic-hosted massive-sulfide deposit of Ivanovka (southern Urals): comparison with modern ocean seafloor analogues. Contributions to Mineralogy and Petrology, 147 (3) 363-383 doi:10.1007/s00410-004-0565-3 | Journal (article/letter/editorial) | | Ivanovka (southern Urals): comparison with modern ocean seafloor analogues Received: 15 August 2003 / Accepted:...minerals are Mg-rich chlorite, variably ferroan talc, (Mg, Si)-rich and (Ca, Na, K)-poor saponite (stevensite)...alteration to chlorite + illite ± actinolite ± saponite ± talc-bearing assemblages and later localized deeper alteration...and mixed ultramafic–mafic breccias were altered to talc-rich rocks with variable amounts of chlorite, carbonate...chlorite and widespread replacement of serpentine by talc. The Ivanovka deposit shows many similarities with |  | | Journal (article/letter/editorial) | | Stockholm University, Stockholm, Sweden 2 School of Ocean and Earth Science, National Oceanography Centre...including buffering of the compositions of the ocean and lithosphere, supporting microbial life and the...International Oceanic Discovery Program (IODP) Hole 1256D. The IODP Hole 1256D drill core provides a unique sample...the plutonic complex. The sulphide population at Hole 1256D is divided into five groups based on mineralogical...alteration. Sulphide leaching is not complete at Hole 1256D and more advanced alteration would mobilise |  | | Journal (article/letter/editorial) | | Constraints on sediment and crustal hydration from drilling exist7 , but their restriction to a few locations...Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, USA. 2...Explorer So van co TF ka ot No F F CD 48° N UC Pacific LCM JdF r F1 idge L2 JdF F2 Latitude L4...contours every 0.5 km s−1 . Numbers along seafloor are ocean bottom seismometers. Dashed lines are isotherms...300 350 47° 30’ N Lower crust and upper mantle (talc+chlor+amph) 0.03 0.01 −50 d 0 44° 30’ N Structural |  | Coggon, Rosalind M., Teagle, Damon A.H., Harris, Michelle, Davidson, Garry J., Alt, Jeffrey C., Brewer, Timothy S. (2016) Hydrothermal contributions to global biogeochemical cycles: Insights from the Macquarie Island ophiolite. Lithos, 264. 329-347 doi:10.1016/j.lithos.2016.08.024 | Journal (article/letter/editorial) | | Davidson c, Jeffrey C. Alt d, Timothy S. Brewer e,1 a Ocean and Earth Science, National Oceanography Centre...2016 Available online 30 August 2016 Keywords: Ocean crust Hydrothermal alteration Biogeochemical cycles...fundamental process in the formation and aging of the ocean crust, with the resultant chemical exchange between...biogeochemical cycles. Sections of hydrothermally altered ocean crust provide time-integrated records of this chemical...Sub-Antarctic Macquarie Island comprises ~10 Ma ocean crust formed at a slow spreading ridge, and is the |  | | Report (chapter) | | within the harzburgite consisting of peridotite (+_ talc) mylonite and high-temperature serpentine mylonite...3 km thick). It is important to note that where deep faulting occurs the actual oceanic crustal thickness...analogue for slow-to intermediate-spreading mid-ocean ridges: (1) episodic magmatism, (2) extensive faulting...probably formed at fast-spreading centres. Modern mid-ocean ridge and back-arc basin spreading centres display...samples via dredge hauls, submersibles and shallow drilling (typically with poor recovery) prohibit collection |  | | Journal (article/letter/editorial) | | normal seawater at - 80-135 ’ C. During uplift of deep-seated gabbro to a near-seafloor position, mafic...ophiolites in the western Tethys, then waters in this ocean basin may not have been buffered to a #‘O-value...sheeted dyke complexes are almost absent, and normally deep-seatedlithologies suchasgabbroand serpentinite were...setting and samples Within east Liguria (Fig. l), ocean-floor sequences are represented by the Vara Complex...paleoenvironments during initial opening of the western Tethyan ocean vary from an early oceanic rift setting with very |  | | Journal (article/letter/editorial) | | participate in alteration processes at relatively deep crustal levels. Results of thermodynamic calculations...fluor-components in basalt alteration phases, such as F-talc. Considering the tendency of F to partition into...affinity for F in subseafloor reaction zones at mid-ocean ridges. Additional experiments are needed to confirm...zones at mid-ocean ridges and at ridge flank localities. Hydrothermal vent fluids at mid-ocean ridges are...hydrothermal alteration. For example, it is well known that talc is a phase or component of hydrous sheet silicates |  | | Journal (article/letter/editorial) | | formation in the Guaymas Basin and in the Salton Sea, under hundreds of meters of sediments, may be approximate...by "exhalations" of metal-rich solutions on the sea floor. But there are massive sulfides very much larger...the extreme thermal gradients prevailing in the ocean-ridge environment; (2) the availability of some...abundant venting of mineralized fluids onto the sea floor may not always generate large mineral deposits...modern massive sulfide is perhaps shown by the Red Sea (10 s t) where dispersion is prevented by the high |  | Teagle, Damon A.H, Alt, Jeffrey C, Chiba, Hitoshi, Humphris, Susan E, Halliday, Alex N (1998) Strontium and oxygen isotopic constraints on fluid mixing, alteration and mineralization in the TAG hydrothermal deposit. Chemical Geology, 149 (1) 1-24 doi:10.1016/s0009-2541(98)00030-8 | Journal (article/letter/editorial) | | Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA Received 12 June...ŽTAG. hydrothermal mound during Leg 158 of the Ocean Drilling Program provide important constraints on the...within an active hydrothermal deposit. Fresh Mid-Ocean Ridge Basalt ŽMORB., with a 87Srr86 Sr of 0.7026...active black smoker chimneys from 218N on the East Pacific Rise. The d18 O SO4 of TAG anhydrite brackets the...basement during hydrothermal recharge at the mid-ocean ridges. q 1998 Elsevier Science B.V. All rights |  | Staudigel, Hubert, Davies, G.R., Hart, Stanley R., Marchant, K.M., Smith, Brian. M. (1995) Large scale isotopic Sr, Nd and O isotopic anatomy of altered oceanic crust: DSDP/ODP sites417/418. Earth and Planetary Science Letters, 130 (1) 169-185 doi:10.1016/0012-821x(94)00263-x | Journal (article/letter/editorial) | | HVAmsterdam, The Netherlands b Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA ’ Scripps Institution...contribute to fluids or partial 1. Introduction Ocean crust generation and its recycling in subduction...facilitated by hydrothermally driven convection of sea water through the oceanic crust. The downwelling...Black smokers and other hydrothermal vents on the ocean floor provide a spectacular opportunity for studying...smokers remove the bulk of all convective heat at mid-ocean ridges. This led to the conjecture that high temperature |  | Yui, Tzen-Fu, Chu, Hao-Tsu, Hwang, Shyh-Lung, Shen, Pouyan, Wu, Tsai-Way, Liou, J.G., Sobolev, Nikolay V. (2010) Geochemistry of garnetiferous Ti–clinohumite rock and talc–kyanite–phengite–almandine schist from the Kokchetav UHP terrane, Kazakhstan: An insight to possible origins of some chemically unusual UHP rocks. Lithos, 118 (1) 131-144 doi:10.1016/j.lithos.2010.04.005 | Journal (article/letter/editorial) | | Geochemistry of garnetiferous Ti–clinohumite rock and talc–kyanite–phengite– almandine schist from the Kokchetav...Eclogite Garnetiferous Ti–clinohumite rock Whiteschist Talc–kyanite–phengite–almandine schist Kokchetav UHP...and eclogites from the Kumdy Kol area, as well as talc–kyanite–phengite–almandine schists (previously named...origins. Both garnetiferous Ti–clinohumite rocks and talc–kyanite– phengite–almandine schists are possibly...exhibit chemical characteristics similar to that of ocean floor basalt, although a few show arc affinity with |
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