Evidence of Microbial Activity in the Formation of Manganese Wads at the Asahidake Hot Spring in Hokkaido, Japan     

Naoki Mita  Hiroyuki Miura 《Resource Geology》2003,53(3):233-238

Abstract. Mt. Asahidake is an active volcano, with more than 90 active wells, in the Daisetsu volcanic group located in central Hokkaido, Japan. Wells along the Yukomanbetsu-sawa River showed high manganese concentrations and associated manganese deposits. These deposits consist of manganese oxides, and the concentration of iron is very low except for one sample collected from the upper reach of the river. Most of the wet samples showed basal diffraction characteristic of todorokite (9.6 Å). Cultivation tests showed that microorganisms were responsible for the oxidation of dissolved Mn²⁺ in the Asahidake hot spring. The dissolved Mn²⁺ concentration in the sterilized hot spring water was unchanged after four days, whereas the Mn²⁺ concentration in the sterilized hot spring water with a small amount of fresh manganese wad was decreased to zero after three days, and manganese oxide formed. This result implies that the activity of microorganism oxidizes dissolved Mn²⁺ and forms manganese oxide at the Asahidake manganese deposits. In addition to Komanoyu hot spring and Yunotaki Falls, this is the third report of microbial activity forming considerable deposits of manganese oxides in hot spring waters.  相似文献   

A Report of IGCP-368 Activities and its Future Programs     

Masaru Yoshida 《Gondwana Research》1998,1(3-4):421-423

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Boron isotopic composition of fumarolic condensates and sassolites from Satsuma Iwo-jima,Japan   总被引：1，自引：0，他引：1  

Tadao Kanzaki  Minoru Yoshida  Masao Nomura  Hidetake Kakihana  Takejiro Ozawa 《Geochimica et cosmochimica acta》1979,43(11):1859-1863

¹¹B/¹⁰B ratios of the high temperature fumarolic gases (>465°C) of this island were found to be constant within the limits of experimental error (¹¹B/¹⁰B = 4.066). This value may represent the ¹¹B/¹⁰B ratio of boron in the andesite magma. ¹¹B/¹⁰B ratios of the low temperature fumarolic gases (<235°C) were found to vary from 4.053 to 4.077. ¹¹B/¹⁰B ratios of some sassolites were approximately equal to that of the fumarolic condensates and the other ones were slightly enriched in ¹⁰B compared to the fumarolic condensates.  相似文献   

Chemical analysis of volcanic gases     

I. Iwasaki  T. Ozawa  M. Yoshida  T. Katsura  M. Kamada 《Bulletin of Volcanology》1965,28(1):3-16

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Proterozoic events in East Gondwana     

M. Yoshida  M. Santosh 《Journal of South American Earth Sciences》1995,8(3-4)

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日本内陆地震活动的迁移与扩散          下载免费PDF全文

吉田明夫  细野耕司 《地震工程学报》1989,11(4):105-116

本文研究了日本内陆及其外围海域发生大地震后的地震活动迁移现象。在所研究的6个震例中,一个共同的特点是,地震活动的迁移总是沿着地壳内的活动地质构造带发生。有时可以根据地震活动的迁移来进一步确定活动构造带的存在。把板块边缘地区的地震活动类比为沿着力学偶合平面迁移和扩散,我们可以认为,岛上的活动构造带对应着地壳块体的力学相互作用边界。地震迁移的形式可能不只一种。在我们所研究的震例中发现了以下特征:地震迁移速度约为几km/年;大地震震源区之间存在着地震空区;在每一条地震带上有一定的地震活动周期。地震迁移的一种可能机制是:由于地壳块体的相对运动,在其边界上的凹凸不平区造成了构造应力集中,这些凹凸不平区相继地发生破裂,形成了地震迁移。  相似文献   

Genesis of the extremely low-K tonalites from the island arc volcanism   总被引：1，自引：0，他引：1  

Satoshi Kanisawa  Takeyoshi Yoshida 《Bulletin of Volcanology》1989,51(5):346-354

The Adachi-Medeshima pumice deposit of the Late Pleistocene age, found in Northeast Japan, contains extremely low-K tonalite fragments, having a wide variation in SiO₂ content but fairly uniform K₂O content (<0.1%). The tonalites coexist with essential dacite fragments. Mineralogical properties of the tonalites are the same as those of the pumice and dacite fragments. Sr isotope ratios of the tonalite, dacite fragments and pumice also fall within a narrow range. By assuming a Rayleigh fractionation model, the concentration of incompatible trace elements in cumulus phases was calculated, and the amounts of major elements were estimated from the fractionation ratios of each mineral and the volume ratio of crystal-liquid. The estimated element abundances of the cumulus phase show a MORB normalized pattern similar to that of the natural tonalite having cumulate textures. Thus, the tonalite represents the cumulus phase precipitated from dacite magma. Equilibrium temperatures and fO₂ of the tonalites, dacite fragments and pumice were estimated from coexisting magnetite-ilmenite pairs at 876°–796° C and –logfO₂ = 9.8–11.9, respectively. The fO₂ is among highest group yet reported. This is a case of extremely low-K tonalite which formed in the island arc system different from the oceanic environments.  相似文献   

The westward drift of the geomagnetic field caused by length-of-day variation, and the topography of the core-mantle boundary     

Shigeo Yoshida  Yozo Hamano 《Geophysical Journal International》1993,114(3):696-710

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III-4 Study on the hull form of the Kaimei-type wave power absorber     

Kimiaki Kudo  Shoji Yoshida 《Ocean Engineering》1985,12(6):570-571

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A Numerical Simulation on the Mesoscale Dynamics of the Spring Bloom in the Sea of Japan     

Tetsuo Yanagi  Goh Onitsuka  Naoki Hirose  John-Hwan Yoon 《Journal of Oceanography》2001,57(6):617-630

The northward migration of spring bloom was observed in the Sea of Japan from April to May 1997 by the Ocean Color and Temperature Scanner (OCTS) on board the Advanced Earth Observing Satellite (ADEOS). This phenomenon is well simulated with a numerical ecosystem model coupled with a hydrodynamic model. The hydrodynamic model is the Geophysical Fluid Dynamics Laboratory (GFDL) Modular Ocean Model (MOM). The ecosystem model consists of five components: dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), phytoplankton, zooplankton and detritus. Results of the numerical ecosystem model suggest that the mesoscale development of the spring bloom in the Sea of Japan is related to that of sea water temperature, and that the bloom is limited by the depletion of DIN. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献