Marine hdrothermal alteration at a Kuroko ore deposit,Kosaka, Japan     

Keiko Hattori  Karlis Muehlenbachs 《Contributions to Mineralogy and Petrology》1980,74(3):285-292

Isotopic compositions were determined for quartz, sericite and bulk rock samples surrounding the Uwamuki no. 4 Kuroko ore body, Kosaka, Japan. ¹⁸O values of quartz from Siliceous Ore (S.O.), main body of Black Ore B.O.) and the upper layer of B.O. are fairly uniform, +8.7 to +10.5. Formation temperatures calculated from fractionation of ¹⁸O between sericite and quartz from B.O. and upper S.O. are 250° to 300° C. The ore-forming fluids had ¹⁸O values of +1 and D values of –10, from isotope compositions of quartz and sericite.Tertiary volcanic rocks surrounding the ore deposits at Kosaka have uniform ¹⁸O values, +8.1±1.0 (n=50), although their bulk chemical compositions are widely varied because of different degrees of alteration. White Rhyolite, which is an intensely altered rhyolite occurring in close association with the Kuroko ore bodies, has also uniform ¹⁸O values, +7.9±0.9 (n=19). Temperatures of alteration are estimated to be around 300° C from the oxygen isotope fractionation between quartz and sericite. Paleozoic basement rocks phyllite and chert, have high ¹⁸O values, +18 and +19. The Sasahata formation of unknown age, which lies between Tertiary and Paleozoic formations, has highly variable ¹⁸O, +8 to +16 (n=4). High ¹⁸O values of the basement rocks and the sharp difference in ¹⁸O at their boundary suggest that the hydrothermal system causing Kuroko mineralization was mainly confined within permeable Tertiary rocks. D values of altered Tertiary volcanic rocks are highly variable ranging from –34 to –64% (n=12). The variation of D does not correlate with change of chemical composition, ¹⁸O values, nor distance from the ore deposits. The relatively high D values of the altered rocks indicate that the major constituent of the hydrothermal fluid was sea water. However, another fluid having lower D must have also participated. The fluid could be evolved sea water modified by interaction with rocks and the admixture of magmatic fluid. The variation in D may suggest that sea water mixed dispersively with the fluid.  相似文献   

Meteoric hydrothermal origin of calcites in “Green Tuff” formations,Miocene age,Japan     

Keiko Hattori  Hitoshi Sakai 《Contributions to Mineralogy and Petrology》1980,73(2):145-150

Oxygen and carbon isotope compositions were determined for calcites from the Green Tuff formations of Miocene age in Japan. Values of ¹⁸O from 24 calcites in altered rocks from 5 districts range from –2 to +16_SMOW, in most cases from 0 to +8_SMOW. The low ¹⁸O values rule out the possibility of their low-temperature origin or any significant contribution of magmatic fluid in the calcite precipitation. These values, coupled with their mineral assemblages, suggest that the calcites formed from meteoric hydrothermal solutions which caused propylitic alteration after the submarine strata became emergent.Values of ¹³C from the calcites show a wide variation from –17 to 0_PDB. Calcites from different districts have different ranges of ¹³C values, indicating that there was no homogeneous reservoir of carbon at the time the calcite formed, and that the carbon had local sources. Carbon isotopic compositions of calcite within ore deposits in the Green Tuff formations range from –19 to 0_PDB, similar to those of calcite in the altered rocks in the same district, suggesting that the carbon in ore calcites was likely supplied from the surrounding rocks through activity of meteoric hydrothermal solutions.  相似文献   

Geochemistry of peat over kimberlites in the Attawapiskat area, James Bay Lowlands, northern Canada     

Kiko H. Hattori  Stewart Hamilton 《Applied Geochemistry》2008,23(12):3767-3782

The James Bay Lowlands, which is the SE part of the Hudson Bay Lowlands, Canada, and within the Paleozoic limestone terrane, is covered mostly by peatlands. Peat samples were examined in the Attawapiskat area, a region of discontinuous permafrost, where more than 19 kimberlite pipes have been found beneath a cover of peat (2–4 m thick) and Quaternary sediments (up to 20 m thick) of Tyrell Sea clay beds and glacial tills. Pore water at a depth of 40 cm in the peat has a consistently low pH, <4, and high Eh, 290 mV, in the areas over limestones far from kimberlites. On the other hand, peat pore water close to kimberlites has a high pH, up to 6.7, and low Eh, down to 49 mV; the values of pH and Eh are inversely correlated. The high pH and low Eh close to kimberlites suggest active serpentinization of olivine in the underlying kimberlites. The bulk compositions of peat indicate precipitation of secondary CaCO₃ and Fe–O–OH. The secondary carbonate contains high concentrations of kimberlite pathfinder elements, such as Ni, rare earth elements (REE) and Y. The ratios of metal concentrations extracted by ammonium acetate solution at pH 5 (AA5) to those in a total digestion confirm that a majority of the divalent cations are hosted by the secondary carbonate, whereas tri-, tetra- and penta-valent cations are not. As these charged cations are not leached in Enzyme Leach, they are most likely adsorbed on Fe–O–OH.The compositions of peat show spatial variation with the distribution of kimberlites, suggesting that they are influenced by the underlying rocks even through there are thick layers of tills and sediments between the bedrocks and peat. However, elevated concentrations of pathfinder elements of kimberlites in bulk peat samples and AA5 leach are not necessarily directly above kimberlites. The diffused metal anomalies around kimberlites are attributed to the dissolution–precipitation of secondary phases (carbonates and Fe–O–OH) in acidic and reduced waters in peat, and the movement of waters through peat. This pilot study suggests that peat compositions do reflect the underlying bedrock compositions. For kimberlite exploration, a geochemical survey of peat is useful to discriminate concealed kimberlites from other anomalies defined by geophysical and other techniques; however, such a geochemical survey is not suitable for delineating the shapes of the concealed kimberlites due to broad dispersed anomalies.  相似文献   

Ordered distribution of aluminum atoms in analcime     

M. Kato  T. Hattori 《Physics and Chemistry of Minerals》1998,25(8):556-565

Based on the connectivity relations among tetrahedron sites and the NMR spectra, we propose an ordered distribution of aluminum atoms in the framework of analcime with space groups of Pbcb and Pcaa. The symmetries of the ordered distributions are formally the same as Pcca. These symmetries are much lower than those reported by others such as Ia3d, I4₁/acd, Ibca, and I2/a. The lowering of symmetry results apparently from the fact that aluminum atoms in the framework of analcime were strictly discriminated from silicon atoms. Dependence of the populations of Si(nAl)s upon Al content was estimated from ²⁹Si MAS NMR, and can be successfully simulated by the ordered distributions. In the simulation, a small number of defects in the Al distribution were introduced into the ordered distribution mainly to adjust the deviation of Al content per unit cell from the typical composition. Analysis of the powder X-ray diffraction patterns of analcime was carried out, which suggests that the space groups proposed in the present work offer a better fit than the ones reported previously. Received: 5 April 1997 / Revised, accepted: 12 March 1998  相似文献   

Re-os isotope systematics of the Taklimakan Desert sands, moraines and river sediments around the taklimakan desert, and of Tibetan soils     

Yuji Hattori  Masatoshi Honda 《Geochimica et cosmochimica acta》2003,67(6):1203-1213

Reported here are the first ¹⁸⁷Os/¹⁸⁸Os ratios and abundances of Os and Re for Taklimakan Desert sands and glacial moraines from the Kunlun Mountains. Osmium isotopic data are also reported for river sediments around the Taklimakan Desert, river sediments from the Kunlun and Tianshan Mountains, Tibetan soils and loesses from the Loess Plateau, as well as Sr and Nd isotopic data for these samples. The Taklimakan Desert sands from various regions show surprisingly homogeneous Os isotopic ratios (¹⁸⁷Os/¹⁸⁸Os = 1.29 ± 0.08) and abundances (Os = 11 ppt), with some variations in Re abundances (Re = 130 to 260 ppt) and ¹⁸⁷Re/¹⁸⁸Os ratios (60 to 140). The ¹⁸⁷Os/¹⁸⁸Os ratios for the Taklimakan Desert sands are close to the average for Kunlun moraines, river sediments around the Taklimakan Desert sands, and the Tibetan soils, supporting the idea that the Taklimakan Desert sands are derived from moraines and river sediments around the desert or from Tibetan soils and are homogenized by aeolian activity in the desert. Furthermore, the Os isotopic data for the sediments studied here are compared with those (¹⁸⁷Os/¹⁸⁸Os = 1.04, Os = 32 ppt, Re = 206 ppt, ¹⁸⁷Re/¹⁸⁸Os = 35) of loesses from the Loess Plateau reported elsewhere, and it is concluded that the Re-Os data for the loess can be used as proxy for the upper continental crust.  相似文献   

Trophic structure and pathways of biogenic carbon flow in the eastern North Water Polynya   总被引：1，自引：0，他引：1  

Jean-ric Tremblay  Hiroshi Hattori  Christine Michel  Marc Ringuette  Zhi-Ping Mei  Connie Lovejoy  Louis Fortier  Keith A. Hobson  David Amiel  Kirk Cochran 《Progress in Oceanography》2006,71(2-4):402

In the eastern North Water, most of the estimated annual new and net production of carbon (C) occurred during the main diatom bloom in 1998. During the bloom, at least 30% of total and new phytoplankton production occurred as dissolved organic carbon (DOC) and was unavailable for short-term assimilation into the herbivorous food web or sinking export. Based on particle interceptor traps and ²³⁴Th deficits, 27% of the particulate primary production (PP) sank out of the upper 50 m, with only 7% and 1% of PP reaching the benthos at shallow (≈200 m) and deep (≈500 m) sites, respectively. Mass balance calculations and grazing estimates agree that ≈79% of PP was ingested by pelagic consumers between April and July. During this period, the vertical flux of biogenic silica (BioSi) at 50 m was equivalent to the total BioSi produced, indicating that all of the diatom production was removed from the euphotic zone as intact cells (direct sinking) or empty frustules (grazing or lysis). The estimated flux of empty frustules was consistent with rates of herbivory by the large, dominant copepods and appendicularians during incubations. Since the carbon demand of the dominant planktivorous bird, Alle alle, amounted to ≈2% of the biomass synthesized by its main prey, the large copepod Calanus hyperboreus, most of the secondary carbon production was available to pelagic carnivores. Stable isotopes indicated that the biomass of predatory amphipods, polar cod and marine mammals was derived from these herbivores, but corresponding carbon fluxes were not quantified. Our analysis shows that a large fraction of PP in the eastern North Water was ingested by consumers in the upper 50 m, leading to substantial carbon respiration and DOC accumulation in surface waters. An increasingly early and prolonged opening of the Artic Ocean is likely to promote the productivity of the herbivorous food web, but not the short-term efficiency of the particulate, biological CO₂ pump.  相似文献   

Apparent Microfloral Response to Organic Degradation on Bathyal ­Seafloor: An Analysis Based on Sediment Fatty Acids     

Takeshi Naganuma  Mutsuo Hattori  Kazumi Akimoto    Jun Hashi­moto  Hiroyasu Momma  & C. Julius Meisel 《Marine Ecology》2001,22(3):267-282

Abstract. Abyssal microfloral succession induced by experimental organic degradation was investigated. Notable changes in amounts and compositions of short-chain (C9-20) sediment fatty acids were observed, which indicated the shift of sediment microflora. Biomarker fatty acids for methanotrophs and sulfate-reducing bacteria dominated. Resultant fatty acid compositions were most closely related to those from a nearby methane seep harboring a dense Calyptogena colony; the clams were also seen in close vicinity of the deployed organic mass. These observations suggest that the organic degradation on the bathyal seafloor stimulates the formation of methanotrophic and thio­trophic microflora, resulting in the formation of a methane-seep-type benthic community.  相似文献   

Distribution and seasonal variation of phosphorus in Tokyo Bay     

Kazuyasu Miyata  Akihiko Hattori 《Journal of Oceanography》1986,42(4):241-254

Phosphorus dynamics in Tokyo Bay waters were investigated along with other oceanographic variables. Seasonal variations of dissolved inorganic phosphorus (DIP) and particulate phosphorus (PP) are inversely correlated with each other, and reflect variation in biological activity. A high concentration of PP in summer surface waters is caused by high primary production. The PP settled in the deeper layer is decomposed, and orthophosphate is regenerated within the water column and in sediments. Even during summer stratification period, the regenerated orthophosphate is occasionally advected upward by wind-induced water mixing and contributes to phytoplankton growth in the upper layer. Some dissolved organic phosphorus is producedin situ from PP, but it may be rapidly decomposed in the water column. The ratios of Cchlorophylla and CN in particulate matter suggest that phytoplankton in the summer surface waters of Tokyo Bay are limited neither by nitrogen nor by phosphorus. The PN ratio in particulate matter varies substantially but it is positively correlated with the ambient concentration of DIP. Phytoplankton take up and store phosphorus within their cells when ambient DIP exceeds their demand. An abundance of total phosphorus in the summer water column can be attributed to increased discharge of river waters, although enhanced release of orthophosphate from anoxic sediments cannot be discounted.  相似文献   

The nitrogen cycle in the sea with special reference to biogeochemical processes     

Akihiko Hattori 《Journal of Oceanography》1982,38(4):245-265

  相似文献   

A review of Pacific salmon hatchery programmes on Hokkaido Island, Japan     

Morita  Kentaro; Saito  Toshihiko; Miyakoshi  Yasuyuki; Fukuwaka  Masa-aki; Nagasawa  Toru; Kaeriyama  Masahide 《ICES Journal of Marine Science》2006,63(7):1353-1363

  相似文献