Talnakhite Associated with Andradite Skarn at Fuka, Okayama Prefecture, Japan

Abstract. Talnakhite occurs in an andradite skarn forming adjacent to a leucocratic quartz monzonite dike intruded into limestone at Fuka. The mineral densely contains exsolution lamellae of chalcopyrite, and the talnakhite-chalcopyrite inter-growth is intimately associated with bornite that contains chalcopyrite as a lattice-form exsolution. The chemical composition of the talnakhite acquired on an electron probe microanalyzer corresponds to Cu_9.00Fe_8.08S_15.92, very close to the ideal chemical formula Cu₉Fe₈S₁₆. Nickel is not detected. The X-ray powder diffraction lines are well indexed on a body-centered cubic cell with a = 10.589 Å. The characteristic (110) reflection of talnakhite is clearly observed at 7.49 Å. The present talnakhite retains the chalcopyrite-like colored polished surface without tarnish in air more than a month.
Talnakhite at Fuka is likely to be derived from breakdown of Cu-rich intermediate solid solution ( iss ), which was in equilibrium with Fe-rich bornite at elevated temperatures. Talnakhite thus formed has survived the subsequent cooling processes, probably because the ƒ_s2 was maintained in suitable levels preventing its decomposition into bornite and chalcopyrite.     

Laboratory annealing experiments of refractory silicate grain analogs using differential scanning calorimetry

Abstract– Exothermic reactions during the annealing of laboratory synthesized amorphous magnesium‐bearing silicate particles used as grain analogs of cosmic dust were detected by differential scanning calorimetry (DSC) in air. With infrared spectroscopy and transmission electron microscopy, we show that cosmic dust could possibly undergo fusion to larger particles, with oxidation of magnesium silicide and crystallization of forsterite as exothermic reactions in the early solar system. The reactions begin at approximately 425, approximately 625, and approximately 1000 K, respectively, and the reaction energies (enthalpies) are at least 727, 4151, and 160.22 J g⁻¹, respectively. During the crystallization of forsterite particles, the spectral evolution of the 10 μm feature from amorphous to crystalline was observed to begin at lower temperature than the crystallization temperature of 1003 K. During spectral evolution at lower temperature, nucleation and/or the formation of nanocrystallites of forsterite at the surface of the grain analogs was observed.     

Remote sensing parameterization of the processes of energy and water cycle over desertification areas

In order to understand the processes of land surface-atmosphere interaction over de-sertification area, it is indispensable to utilize of satellite remote sensing. Two scenes of LandsatTM were used to produce a set of maps of surface reflectance, MSAVI, vegetation coverage, sur-face temperature, net radiation, soil heat flux, sensible heat flux and latent heat flux. Statisticalanalysis based on these maps revealed some quantitative significant land surface characteristics.Future developments of the method are also discussed.     

Chemistry of Late Early Triassic Siliceous Claystone ('Toishi-type' Shale) from the Oritate Area, Sambosan Belt, Kyushu, Southwest Japan

Abstract. Inorganic chemical compositions are determined for late Early Triassic siliceous claystone ('Toishi-type' shale) and associated chert from Oritate area, Sambosan Belt, Kyushu, southwest Japan. The siliceous claystone is similar in chemical composition to Post-Archean Australian Shale (PAAS), but is depleted in Ca, Sr, Mn, and Fe and slightly enriched in Cu, Zn, P, and rare earth elements (REEs). The siliceous claystone and associated chert have flat REE patterns with positive Eu anomalies and no distinct Ce anomaly. The siliceous claystone and associated chert have largely constant Ti/Al, Th/Al, and Nb/Al ratios compared to the variable ratios found in siliceous shale and sandstone deposited close to land in a trench setting. This suggests that the claystone and chert were deposited in a deep-sea pelagic environment and were derived mainly from the suspended fraction, including eolian dust and material transported from distant lands, rather than from turbidity currents that occurred close to land. The low Ca contents of the analyzed rocks indicate deposition below the calcium-carbonate compensation depth. The depletion of Mn and Fe, and no distinct Ce anomaly in the Oritate siliceous claystone are also evident, being similar to those in samples from the Sasayama and Kinkazan sections in the Mino-Tanba Belt, where oceanic anoxia developed during the Late Permian to earliest Triassic. This might suggest that oceanic anoxia prevailed through to the late Early Triassic.     

Studies on a very flare-active δ group: Peculiar δ spot evolution and inferred subsurface magnetic rope structure

The complex subsurface magnetic rope structure of a very flare-active isolated group (McMath 13043, July 1974) is studied by means of high-resolution evolutionary data from BBSO magnetic and velocity data. This group showed unusually fast evolution accompanied by a number of intense flares occurring on the neutral line of a spot, and provided an excellent opportunity to study the inherent relation of flare occurrence to changes of the magnetic configuration. We first examine the abnormal evolution of this group started by formation of a large, compact, reversed spot by squeezing of multipoles. The configuration was deformed by penetration into the opposite polarity umbra and its subsequent disappearance, decaying by rapid shear motions. Strong transverse fields over 4000 G were detected in the penumbrae and some umbral components.Combining these data with the August 1972 region, the evolution of these isolated groups is shown to decompose into two flare-associated elementary modes: (A) shearing produced by spot growth and (B) reduction of shear as spots disappear. We propose a model of an emerging twisted magnetic knot to explain the two modes and apply realistically to the present evolution. The inferred magnetic topological structure of this region consists of tightly twisted (sheet-like) knots and a long-winding twisted rope with an internally reversed loop and a hooked bottom struture. Their consecutive emergences are suggested to explain the abnormal evolution of this 5 group. This result indicates that the origin of the concentrated flare activity in these isolated groups may be traced to internal magnetic activity responsible for forming anomalous magnetic ropes.The author died on January 2, 1990. This paper, prepared for publication at the time of his death, was edited by Professor H. Zirin.     

基于多测点LA-ICPMS的耳石核区元素指纹分析技术及其在鱼类群体识别中的实证研究

构建了多测点激光剥蚀取样（LA）-ICPMS元素分析-剥蚀点显微结构验证的耳石核区元素指纹分析技术,以此进行了五个刀鲚群体（辽东湾、渤海湾、黄河口、胶州湾及长江口群体）识别的实证研究。结果发现,耳石核区Sr：Ca和Ba：Ca比值是有效识别各地理群体的元素指纹,基于二者的各群体判别成功率在46.2%—92.3%之间,总体...     

The flares of August 1972

We present the analysis of observations of the August flares at Big Bear and Tel Aviv, involving monochromatic movies, magnetograms and spectra. In each flare the observations fit a model of particle acceleration in the chromosphere with emission produced by impact and by heating by the energetic electrons and protons. The region showed inverted polarity and high gradients from birth, and flares appear due to strong magnetic shears and gradients across the neutral line produced by sunspot motions. Post flare loops show a strong change from sheared, force-free fields parallel to potential-field-like loops, perpendicular to the neutral line above the surface.We detected fast (5 s duration) small (1') flashes in 3835 at the footpoints of flux loops in the August 2 impulsive flare at 1838 UT, which may be explained by dumping of > 50 keV electrons accelerated in individual flux loops. The flashes show excellent time and intensity agreement with > 45 keV X-rays. In the less impulsive 2000 UT flare a less impulsive wave of emission in 3835 moved with the separating footpoints. The thick target model of X-ray production gives a consistent model for X-ray, 3835 and microwave emission in the 18:38 UT event.Spectra of the August 7 flare show emission 12 Å FWHM in flare kernels, but only 1 to 2 Å wide in the rest of the flare. The kernels thus produce most of the H emission. The total emission in H in the August 4 and August 7 flares was about 2 × 10³⁰ erg. We belive this dependable value more accurate than previous larger estimates for great flares. The time dependence of total H emission agrees with radio and X-ray data much better than area measurements which depend on the weaker halo.Absorption line spectra show a large (6 km/s^-1) photospheric velocity discontinuity across the neutral line, corresponding to sheared flow across that line.This work has been supported by NASA under NGR 05 002 034, NSF Atmospheric Sciences program under GA 24015, and AFCRL under FI9628-73-C-0085.     

Lower Devonian tentaculite bed in the Satun area, southern peninsular Thailand

A Lower Devonian (Emsian) tentaculite fauna including Nowakia acuaria [Richer, R., 1854. Thüringische Tentaculiten. Zeitschr. Deutsch. Geol. Gesellsch. 6, 275–290] occurs in black shale in the basal part of a siliciclastic sequence exposed north of Satun, southern peninsular Thailand. Similar tentaculite beds with Nowakia have been reported from several areas in the Fang, Sri Sawat, and Trang areas of Thailand, the Langkawi Islands and the Mahang–Baling areas of Malaysia. The depositional environments in which the tentaculite-bearing black shale accumulated extended from modern northern Thailand to northwestern Malaysia during the Early Devonian (Emsian).     

Occurrence of Two Distinct Types of Tissue Inhibitors of Metallo-proteinases-2 in Fugu rubripes

In this study, genes of two distinct tissue inhibitors of metalloproteinases-2 （TIMP-2） from Japanese puffer fish Fugu rubripes, Fugu TIMP-2a and TIMP-2b, were cloned. The open reading frames of Fugu TIMP-2a and TIMP-2b cDNAs are composed of 660 and 657 nucleotides and 220 and 219 amino acids, respectively. Both Fugu TIMP-2s contain 12 cysteine residues, which might form six disulfide bonds as in other animals＇ TIMP-2s. Reverse-transcribed polymerase chain reaction analysis showed the mRNAs of Fugu TIMP-2a and TIMP-2b to be expressed in some tissues examined with different expression patterns. These findings suggest that the two distinct Fugu TIMP-2s might perform different functions in Fugu tissues.     

Evolution of fibrils with special reference to flare activity

We show observational results on the pre-flare evolutions of H structures as well as the developments of H flares. It is shown that the chromospheric features are brought to a sheared state before flares due to motions of footpoints which correspond to particular sunspot motions. Generally in evolutions of the chromospheric features it is found that motions and reconnections of the footpoints play essential roles. The following three stages are found for development of the neutral line filament before flares: (1) formation of a filament as a result of reconnection; (2) increase of the shear of the filament due to the shear motion; and (3) reconnection of fine components of the filament to form an elongated component immediately before flares. We further show developments of two particular flares with and without the filament, and point out basic release processes of flares. The flare that occurred at the filament (July 5, 1974) started with the activation of the elongated component of the filament after the process (3). The main phase of a two-ribbon flare is considered as the rises of short components of the filament triggered by the rising motion of the elongated component. The flare of September 10, 1974 occurred at the region where fibrils connect the sunspots in distorted form. Pre-flare distortion was produced by translational rotation of the sunspot. Development of this two-ribbon flare is interpreted as being due to successive rises of the fibrils with a self-trigger mechanism.On leave from Tokyo Astronomical Observatory (present address).