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| 1 | Microtexture and Distribution of Minerals in Hydrothermal Barite-Silica Chimney from the Franklin Seamount, SW Pacific: Constraints on Mode of Formation显示文摘An extinct hydrothermal barite-silica chimney from the Franklin Seamount of the Woodlark Basin, in the southwestern Pacific Ocean, was investigated for mineral distribution and geochemical composition. Six layers on either side of the orifice of a chimney show significant disparity in color, mineral assemblage and major element composition. Electron microscope(SEM) images reveal that the peripheral wall of the chimney is composed of colloform silica, suggesting that incipient precipitation of silica-saturated hydrothermal fluid initiated the development of the chimney wall. Intermediate layers, between the exterior wall and the inner fluid-orifice, dominate with barite and sulfides. Low Sr-to-Ba ratios(SrO/BaO = 0.015–0.017) indicate restricted fluid-seawater mixing, which causes relatively high-temperature formation of the intermediate layers. Whereas the innermost layer bordering the chimney orifice is characterized by more silica and a higher Sr-to-Ba ratio(SrO/BaO = 0.023), could have formed due to a paragenetic shift from a high-temperature active phase to a cooler waning stage of formation. A paragenetic shift is also probably responsible for the change in mineral formation mechanism that resulted in the textural variation of barite and colloform silica developed during different growth phases of this barite-silica chimney. | Durbar RAY Dalayya KOTA Pranab DAS L.Surya Prakash V.D.KHEDEKAR Anil L.PAROPKARI Abhay V.MUDHOLKAR | 2014 | Acta Geologica Sinica(English Edition)2014，88，1： | 6 |
| 2 | Formation of hydrothermal deposits at Kings Triple Junction, northern Lau back-arc basin SW Pacific: The geochemical perspectives 显示文摘 | Anil L P Durbar R Balaram V | 2001 | Journal of AsianEarth Sciences2001，38，34： | 1 |
| 3 | Effect of small amounts of nitrogen and silicon on microstructure and properties of MAR-M002 nickel-base superalloy显示文摘 | Durbar G L R Osgerby S Quested P N | | 0，，04： | 1 |
| 4 | RNA sequence analysis using covariance models显示文摘 | Ennysr Durbar | | 0，，11： | 1 |
| 5 | Mineralogical and geochemical variation in hydrothermal sulfides from Vienna Woods field,Manus Basin,Papua New Guinea:constraints on their evolution显示文摘Polymetallic sulfides from two hydrothermal chimneys and talus deposit from the Vienna Woods field of Manus Basin were studied for mineralogy,elemental composition,and S-isotope ratio to understand their evolution.The factors including the nature of source fluid,mineral paragenesis,and related geochemical processes have been discussed.Mineralogy and elemental concentration of Cu and Fe-rich large chimney at the central part of this hydrothermal field was completely different from the smaller Zn-rich peripheral chimney and Fe-rich talus deposit,suggesting the variable degree of alterations generate physico-chemically different source fluids responsible for these hydrothermal structures.Similarly,S-isotope ratios also indicate chemically diverse fluids and different modes of precipitation were involved in their evolution.Distinct mineral zonings and associated elemental and isotopic compositions within individual deposit confirm paragenetic shifts were involved during their growth process. | RAY Durbar BANERJEE Ranadip MAZUMDER Aninda PAROPKARI Anil L. MUKHOPADHYAY Subir BALAKRISHNAN Srinivasan | 2018 | Acta Oceanologica Sinica2018，37，4： | 1 |
| 6 | Effect of small amounts of nitrogen and silicon on microstructure and properties of MAR-M002 nickel-base superalloy显示文摘 | Durbar G L R Osgerby S Quested P N | 1984 | Met Technol1984，11，4： | 1 |
| 7 | Mineralogy and geochemistry of hydrothermal sulphide from a submarine volcanic high at 18°36.4'S Central Lau Spreading Center, Southwest Pacific显示文摘We report the mineralogy and geochemistry of hydrothermal sulphide from the crater of a volcanic high near 18°36.4′S of the Central Lau Spreading Center.During 1990s,that volcanic structure was reported active and sulphide samples were collected by MIR submersible.A section of a chimney-like structure from the crater-floor was studied here.The Fe-depleted sphalerites,and Co-depleted pyrites in that chimney were similar to those commonly found in low to moderate temperature(<300℃)sulphides from sediment-starved hydrothermal systems.Bulk analyses of three parts of that chimney section showed substantial enrichment of Zn(18%–20%)and Fe(14%–27%)but depletion of Cu(0.8%–1.3%).In chondrite-normalized rare earth element-patterns,the significant negative Ce-anomalies(Ce/Ce*=0.27–0.39)and weakly positive Eu-anomalies(Eu/Eu*=1.60–1.68)suggested sulphide mineralisation took place from reduced low-temperature fluid.The depleted concentration of lithophiles in this sulphide indicates restricted contribution of sub-ducting plate in genesis of source fluid as compared to those from other parts of Lau Spreading Centre.Uniform mineralogy and bulk composition of subsamples across the chimney section suggests barely any alteration of fluid composition and/or mode of mineralisation occurred during its growth. | Durbar Ray Anil L.Paropkari | 2023 | Acta Oceanologica Sinica2023，42，5： | 0 |
| 8 | Geochemistry of volcanic glass from Mahanadi offshore region,eastern continental margin of India:Constraints on the contribution of latest Toba super-eruption显示文摘The tephra layers in multiple sediment cores from the offshore region of the Mahanadi basin in the northern Bay of Bengal were investigated for possible volcanic sources. The glass shards from those tephra layers were studied for size distribution, texture, and elemental geochemistry to establish chronostratigraphic markers for regional and global Quaternary correlation. The textural features of fine-grained(silty) volcanic glasses suggest the distal source of these tephra deposits. Major element composition with elevated SiO_(2( contents ranging between75%–76% and dominance of K_(2)O(> 4.5%) over CaO(< 0.9%) suggest ashes have originated from siliceous rhyolitic melts, similar to the petrographic composition of tephra from the Toba volcano. The bulk trace element compositions of the same glass shards were comparable with those reported in the youngest Toba tephra reported elsewhere. Likewise, the LREE-dominated chondrite normalized REE profiles of tephra from the Mahanadi basin closely resemble the characteristic REE patterns in Toba ash from other parts of the Indian Ocean and thus confirmed the contribution of the youngest Toba super-eruption for this ash layers. | Muralidhar Kocherla Durbar Ray Manavalan Satyanarayanan Hilda Joao Virsen Gaikwad PB Ramamurty | 2024 | Acta Oceanologica Sinica2024，43，2： | 0 |
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