Gzhelian-Asselian Palaeoaplysina reef in atoll carbonates of the Akiyoshi Terrane, SW Japan: A peculiar community in the Panthalassan reef evolution     

Tsutomu NAKAZAWA  Katsumi UENO 《地球学报》2009,30(Z1):44-47

A Palaeoaplysina reef occurs in the Gzhelian-Asselian interval of the Panthalassan atoll carbonates, Akiyoshi Terrane, SW Japan. An alga, Palaeoaplysina was paleogeographically distributed mainly along the northern margin of Pangea and is regarded as a boreal element. Its distribution extended to the tropical or subtropical area of the Panthalassa Ocean caused by global cooling during an icehouse period. The Palaeoaplysina community was succeeded by a calcisponge community in the late Early Permian. This biotic turnover almost corresponds to the climatic change from icehouse to greenhouse conditions and coincides with the timing of a superplume activity in the mid-Panthalassa Ocean.  相似文献   

A Study Of The Atmospheric Boundary Layer Using Radon And Air Pollutants As Tracers     

Toshio Kataoka  Eiji Yunoki  Mitsuo Shimizu  Tadashige Mori  Osamu Tsukamoto  Yukitaka Ohashi  Ken Sahashi  Toshihiko Maitani  Koh’ichi Miyashita  Toru Iwata  Yoko Fujikawa  Akira Kudo  Roger H. Shaw 《Boundary-Layer Meteorology》2001,101(2):131-156

Concentrations of radon ²²²Rn andair pollutants, meteorological parametersnear the surface and vertical profiles of meteorological elements were measured atUchio (Okayama City, Okayama Prefecture, Japan) 12 km north from the coast ofthe Inland Sea of Japan. In the nighttime, the ²²²Rn concentration increased in the case of weak winds, but did not increase as much in the case of moderate or strong winds, as had been expected. In the daytime, the ²²²Rn concentrationheld at a slightly higher than average level for the period from sunrise to about 1100 JST. It is considered that this phenomenon is due to a period of morning calm, that is, a transition period from land breeze to sea breeze.NO, which is sensitive to traffic volume,brought information concerning advection.Oxidant concentrations,which reflect the availability of sunlight,acted in the reverse manner to ²²²Rnconcentrations. Thus, a set of ²²²Rn and air pollutants could provide useful information regarding the local conditions of the atmospheric boundary layer.  相似文献   

A new proposal for simplified design of buried steel pipes crossing active faults     

Shiro Takada  Nemat Hassani  Katsumi Fukuda 《地震工程与结构动力学》2001,30(8):1243-1257

Simplified design methods for obtaining the maximum strain in pipelines crossing active faults proposed by Newmark, Kennedy and Wang have not considered the section deformation of the pipe. In this study, a new simplified method is developed for obtaining the maximum strain in steel pipes crossing faults considering non‐linearity of material and geometry of pipe section. It is assumed that the pipe will bend near the fault and the geometry of pipe in the longitudinal direction will change according to a bent deformation. On the other hand, the relation between maximum strain and bent angle has been obtained using a beam–shell hybrid FEM for different pipe‐fault conditions. The developed method can be used for calculating the maximum strains for fault‐crossing steel pipes with different angles of crossing both in tension and compression, by considering the deformation of the pipe cross‐section. Copyright © 2001 John Wiley Sons, Ltd.  相似文献   

Anomalous crustal strain prior to the 1923 Kanto,Japan, earthquake as deduced from analysis of old triangulation data     

Yoichiro Fujii  Katsumi Nakane 《Pure and Applied Geophysics》1979,117(6):1301-1315

Horizontal earth's strains preceding the Kanto, Japan, earthquake of 1, September 1923, are deduced from the analysis of the old triangulation data. The anomalous strains that are several times larger than usual tectonic strain are found in the western part of Tokyo Bay, Sagamihara district, Japan for the observational period 1882/91–1898/1910, while any significant strain is not revealed in the other region of the Kanto district. The Kanto district was surveyed twice during the period 1883/85–1890/92 in the west and during the period 1890/92–1897/99 in the east respectively. The polarity of the detected anomalous strains, the directions and the signs of the principal strains, are quite the same as those of the postseismic crustal strains during the period 1924–74, and are reversed as compared to the coseismic one.The Philippine Sea plate thrusts under the South Kanto district with N25°W direction and pulls down the land during the interseismic period. The aseismic reverse faulting would begin several decades before the 1923 Kanto earthquake along the deep interface between the Asian plate and the convergent Philippine Sea plate. The down-going along the locked part of the interface would be accelerated, thus the compressional stress on the earth's surface might be concentrated over the deep fault plane together with the acceleration of the subsidence at the tip of the peninsula close to the Sagami trough.  相似文献   

An international turbulence comparison experiment (ITCE 1976)   总被引：1，自引：0，他引：1  

A. J. Dyer  J. R. Garratt  R. J. Francey  I. C. McIlroy  N. E. Bacon  P. Hyson  E. F. Bradley  O. T. Denmead  L. R. Tsvang  Y. A. Volkov  B. M. Koprov  L. G. Elagina  K. Sahashi  N. Monji  T. Hanafusa  O. Tsukamoto  P. Frenzen  B. B. Hicks  M. Wesely  M. Miyake  W. Shaw 《Boundary-Layer Meteorology》1982,24(2):181-209

Turbulence data for the International Turbulence Comparison Experiment (ITCE) held at Conargo, N.S.W. (35° 18′ S., 145° 10′ E.) during October, 1976 are analysed. The standard deviation % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiqado% hagaqbamaaCaaaleqabaGaaGOmaaaakiaacMcadaahaaWcbeqaaiaa% igdacaGGVaGaaGOmaaaaaaa!3B93!\[(s'^2 )^{1/2} \] and covariance % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaace% WG3bGbauaaceWGZbGbauaaaaaaaa!3809!\[\overline {w's'} \] measured by a number of instruments and instrument arrays have been compared to assess their field performance and calibration accuracy. Satisfactory agreement, i.e. typically 5% for % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikamaana% aabaGabm4CayaafaWaaWbaaSqabeaacaaIYaaaaaaakiaacMcadaah% aaWcbeqaaiaaigdacaGGVaGaaGOmaaaaaaa!3BA4!\[(\overline {s'^2 } )^{1/2} \] (except in humidity) and of the order of 20% for % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiqado% hagaqbamaaCaaaleqabaGaaGOmaaaakiaacMcadaahaaWcbeqaaiaa% igdacaGGVaGaaGOmaaaaaaa!3B93!\[(s'^2 )^{1/2} \], was achieved, but only after consideration of:

1. Instrumental response at high frequencies.
2. Flow distortion induced by instruments and supporting structures.
3. Spatial separation of instruments used for covariance measurements.
4. Statistical errors associated with single point measurements over a finite averaging time, and with lateral separation of two sensor arrays being compared.

  相似文献   

Fusulinoidean faunal succession of a Paleo–Tethyan oceanic seamount in the Changning–Menglian Belt, West Yunnan, Southwest China: An overview     

Katsumi Ueno  Yujing Wang  Xiangdong Wang 《Island Arc》2003,12(2):145-161

Abstract   Fusulinoidean faunal succession from Paleo–Tethyan seamount-type carbonates of the Yutangzhai section in the Central zone of the Changning–Menglian Belt of West Yunnan, Southwest China, is presented for the first time. The Changning–Menglian Belt is one of the orogenic belts that represent the closed main Paleo–Tethys in East Asia. The Yutangzhai section is represented by basalts and overlying carbonates, about 1100 m thick. It exhibits a continuous faunal succession composed of 17 fusulinoidean assemblages ranging from the Serpukhovian (late Mississippian/late Early Carboniferous) to Midian/Capitanian (late Middle Permian/late Guadalupian). No significant faunal break can be recognized in this section. The generic and some specific composition of the Yutangzhai assemblages indicates that the faunal succession is similar to those observed in Tethyan and Panthalassan areas and is of tropical Tethyan type although their generic diversity is definitely lower than those of Paleo–Tethyan shelves, such as South China, Indochina, and Central Asia. Throughout the Yutangzhai section, the carbonate rocks are essentially massive, very pure in composition, and devoid of terrigenous siliciclastic inputs. These lithologic characters are identical to those observed in accreted shallow-marine carbonate successions of seamount origin in Permian and Jurassic accretionary complexes of Japan, for example the Akiyoshi Limestone. This evidence further demonstrates the seamount origin of the basalt–limestone succession in the Central zone of the Changning–Menglian Belt from the viewpoint of lithofacies. In middle Mississippian (middle Early Carboniferous) time, oceanic submarine volcanism that was probably related to hot spot activities formed a number of seamounts and oceanic plateaus. It was active not only in the Panthalassa, but also in the Paleo–Tethys.  相似文献   

Microbial Diversity in Hydrothermal Systems and Their Influence on Geological Environments     

Kousuke ISHII  Katsumi MARUMO 《Resource Geology》2002,52(2):135-146

Abstract: Microorganisms found at terrestrial and seafloor hydrothermal systems are classified based on their optimum growth temperatures. Prokaryotes exhibiting optimum growth temperatures above 45C are defined as thermophiles, while those with optimum growth temperatures above 80C are called hyperthermophiles. Hyperthermophiles have chemically and thermodynamically stable cytoplasmic‐membrane consisting of ether–lipids. Hyperthermophiles observed at temperature up to 113C in seafloor hydrothermal areas should have thermostable proteins. Presumably, the thermostable proteins are replacing certain amino acid residue by proline instead of alanine in order to increase hydrogen bonds and salt bridges. Microorganisms inhabiting terrestrial and seafloor hydrothermal areas obtain energy mainly by use of chemical disequilibrium, so that their habitat may be restricted to the redox boundary between ambient water and reduced hydrothermal fluids. Among more than 200 species of cultivable thermophiles and hyperthermophiles, hyperthermophiles mainly obtain energy by sulfur reduction, because this reaction can produce energy efficiently at > 80C. Some hyperthermophilic sulfur reducers can reduce Cr(VI), Mn(IV), Fe(III), Co(III), As(V), Se(VI), Tc(VII), Au(III) and U(VI) through hydrogen or organic compounds that act as reducing agents for yielding energy. Some hyperther‐mophiles use W instead of Mo for activating their enzymes. Bacteria can pump out toxic metal ions from their cells, however toxic metal resistance systems of archaea, including hyperthermophiles, have not yet been studied. Methane producing hyperthermophiles can yield energy by the autotrophic reaction, when sufficient carbon dioxide and molecular hydrogen can be supplied and methane can be removed from hydrothermal systems. If nitrogen can be supplied into a hydrothermal system, hydrogen oxidization by nitrogen species (e.g. NO₃^‐, NO₂^‐, NO and N₂O) may be expected through the metabolism of some hyperthermophiles.  相似文献   

Missing ophiolitic rocks along the Mae Yuam Fault as the Gondwana–Tethys divide in north-west Thailand     

Ken-ichiro Hisada  Masaaki Sugiyama  Katsumi Ueno  Punya Charusiri  Shoji Arai 《Island Arc》2004,13(1):119-127

Abstract Thailand comprises two continental blocks: Sibumasu and Indochina. The clastic rocks of the Triassic Mae Sariang Group are distributed in the Mae Hong Son–Mae Sariang area, north‐west Thailand, which corresponds to the central part of Sibumasu. The clastic rocks yield abundant detrital chromian spinels, indicating a source of ultramafic/mafic rocks. The chemistry of the detrital chromian spinels suggests that they were derived from three different rock types: ocean‐floor peridotite, chromitite and intraplate basalt, and that ophiolitic rocks were exposed in the area, where there are no outcrops of them at present. Exposition of an ophiolitic complex denotes a suture zone or other tectonic boundary. The discovery of chromian spinels suggests that the Gondwana–Tethys divide is located along the Mae Yuam Fault zone. Both paleontological and tectonic aspects support this conclusion.  相似文献   

Geochemical implications from Sr isotopes and K-Ar age determinations for the cook-austral islands chain     

Jun-Ichi Matsuda  Kenji Notsu  Jun Okano  Katsumi Yaskawa  Leonard Chungue 《Tectonophysics》1984,104(1-2)

Sr isotopes and K-Ar ages were determined for volcanic rocks from three islands, Samoa, Rarotonga and Rurutu in the Austral-Gilbert-Marshall chain. We have established that Rurutu originated from the same “hot spot” as Tubuai and Raivavae in the Cook-Austral chain as indicated by its 11 m.y. K-Ar age and ( ) ratios. The ( ) ratios for Rurutu, Tubuai and Raivavae lie in the restricted range 0.7026–0.7035. K-Ar ages of all volcanic rocks from Samoa and Rarotonga are all less than 4 m.y. and their ( ) ratios are much higher than those in Rurutu, Tubuai and Raivavae. These findings suggest that Samoa and Rarotonga did not originate in a single hot spot for the Cook-Austral islands.  相似文献   

A preliminary report of development of high resolution phase shift interferometry for the assessment of nuclear waster disposal     

A. Ueda  S. Ueta  K. Kato  K. Tsukamoto  H. Sato  Y. Nishimura 《Journal of Geochemical Exploration》2006,88(1-3):355

A newly designed phase-shift interferometer and a reaction cell have been developed to investigate the alteration process and the safety assessment of an artificial barrier and the surrounding rocks during interaction with high pH solutions in repository sites.We advanced a conventional interferometer with a laser to a phase-shift interferometer with a white-light. Developments and evaluations were also made on the reaction cells at high temperature, high pressure and high pH conditions. Potentials of our established system, involving a newly equipped image-processing, were practically tested by dissolution experiments on calcite in various aqueous solutions. It was successfully confirmed that the developed phase-shift interferometer system can detect very slow retreat in short-periods with high enough precision to evaluate the dissolution kinetics.  相似文献