Electrical conductivity of partial molten carbonate peridotite

International audienceIn order to investigate the effect of carbonate-content in partial melt on bulk conductivity under high pressure, electrical conductivity measurements were performed on carbonate melt-bearing peridotites using a Kawai-type multi-anvil apparatus. The starting materials were composed of spinel lherzolite (KLB1) with small amounts of dolomite (1 and 3 wt.%). To obtain various melt fractions, annealing experiments were performed at different temperatures above 1400 K at 3 GPa. At low temperatures (⩽ 1500 K), the conductivity was distinctly higher than that of carbonate-free peridotite and close to that of the carbonatite melt-bearing olivine aggregates. Although the sample conductivity increased with increasing temperature, the rate at which the conductivity increases was small and the conductivity approached that of silicate melt-bearing peridotite. CO2 concentration in the partial melt decreased with increasing annealing temperature. Thus, the small increase of the conductivity with annealing temperature is attributed to a decrease of the melt conductivity due to a decrease in carbonate content in the partial melt. As the carbonate concentration in the melt decreases, the estimated melt conductivity approaches that of the basaltic melt. Therefore, conductivity enhancement by the carbonate-bearing melt is very effective at temperature just above that of the carbonate peridotite solidus

Electrical conductivity of basaltic and carbonatite melt-bearing peridotites at high pressures: Implications for melt distribution and melt fraction in the upper mantle

International audienceElectrical impedance measurements were performed on two types of partial molten samples with basaltic and carbonatitic melts in a Kawai-type multi-anvil apparatus in order to investigate melt fraction-conductivity relationships and melt distribution of the partial molten mantle peridotite under high pressure. The silicate samples were composed of San Carlos olivine with various amounts of mid-ocean ridge basalt (MORB), and the carbonate samples were a mixture of San Carlos olivine with various amounts of carbonatite. High-pressure experiments on the silicate and carbonate systems were performed up to 1600 K at 1.5 GPa and up to at least 1650 K at 3 GPa, respectively. The sample conductivity increased with increasing melt fraction. Carbonatite-bearing samples show approximately one order of magnitude higher conductivity than basalt-bearing ones at the similar melt fraction. A linear relationship between log conductivity (σbulk) and log melt fraction (phi) can be expressed well by the Archie's law (Archie, 1942) (σbulk/σmelt = Cphin) with parameters C = 0.68 and 0.97, n = 0.87 and 1.13 for silicate and carbonate systems, respectively. Comparison of the electrical conductivity data with theoretical predictions for melt distribution indicates that the model assuming that the grain boundary is completely wetted by melt is the most preferable melt geometry. The gradual change of conductivity with melt fraction suggests no permeability jump due to melt percolation at a certain melt fraction. The melt fraction of the partial molten region in the upper mantle can be estimated to be 1-3% and not, vert, similar 0.3% for basaltic melt and carbonatite melt, respectively

Postmortem and helminthological examination of seabirds killed by oil spilled at Ishikari, Hokkaido, Japan, in November 2004

Postmortems and helminthological examinations were performed on beached seabirds killed by oil spilled from a grounded freighter at Ishikari, Hokkaido, Japan in November 13, 2004. The carcasses were covered with crude oil, but they had adequate subcutaneous fat levels. Gross pathological findings consisting of gastric ulcers, pulmonary edema, enlarged spleens and blackish liquid contents in the digestive tracts suggested that they had a rapid progression to death caused by a loss of ascending force, hypothermia and dehydration. Although the visceral organs had degenerated, no direct evidence of mortality caused by ingesting oil was observed. However, extensive acute inflammatory reactions caused by large numbers of mature and immature nematodes (Contracaecum rudolphii) deeply penetrating the gastric walls was observed in two of the birds. Helminthological investigations were conducted on 21 birds from six species, namely: Phalacrocorax capillatus, Aythya marila, Cerorhinca monocerata, Synthliboramphus antiquus, Aethia cristatella, and Brachyramphus perdix. Thirteen helminth species were obtained and identified, including eight nematodes (Eucoleus contortus, Baruscapillaria mergi, B. rudolphii, Amidostomum acutum, C. rudolphii, Tetrameres fissispina, Cosmocephalus obvelatus and Stegophorus stercorarii), three trematodes (Aporchis sp., Hyptiasmus sp. and Renicola sp.), one cestode (Diorchis nyrocae) and one acanthocephalan species (Andracantha phalacrocoracis). Of these, B. rudolphii from S. antiquus, C. rudolphii and Renicola sp. from A. cristatella, and C. obvelatus and Renicola sp. from B. perdix were first host records. Additionally, B. rudolphii was the first geographical record of this species in Japan

Trials for Risk Assessment of Japanese Encephalitis Based on Serologic Surveys of Wild Animals

Flavivirus Encephaliti

Filarial nematodes belonging to the superorders Diplotriaenoidea and Aproctoidea from wild and captive birds in Japan

Eight species of filarial nematodes of the superorders Diplotriaenoidea and Aproctoidea were collected from the lung, air sac, abdominal cavity, and subdermal layer of the neck of wild and captive birds in Japan. The species of the filarial nematodes were identified as Diplotriaena bargusinica, D. henryi, Serratospiculum kwangsiensis, S. tendo, Hamatospiculum accipitris, H. cylindricum, H. quadridens, and Lissonema noctuae based on morphometry and pathogenicity. D. henryi from Poecile varius, H. accipitris from Accipiter gentilis, H. cylindricum from Lanius bucephalus and H. quadridens from Otus flammeolus represent the first host records worldwide. Moreover, D. henryi, S. kwangsiensis, H. cylindricum, and L. noctuae were the first geographical records from Japan

Ornithomya fringillina (Diptera: Hippoboscidae) collected from a goldcrest, Regulus regulus in Kushiro, Hokkaido, Japan

The carcass of a juvenile male goldcrest, Regulus regulus, was collected in November 14, 2016 at Kushiro, Hokkaido, Japan. Postmortem examination was performed and a louse-fly was obtained from its body surface. The findings suggested that the bird collided with a window and died by cerebral contusion and circulatory disorder due to pulmonary contusion. In addition, the fly was identified as Ornithomya fringillina based on morphological characters. To the best of our knowledge, this is the first record of O. fringillina from R. regulus in Kushiro region

First record of chewing lice Brueelia pyrrhularum Eichler, 1954 (Ischnocera: Philopteridae) on an Eurasian bullfinch, Pyrrhula pyrrhula L in Kushiro, Hokkaido, Japan

A deceased male adult Eurasian bullfinch, Pyrrhula pyrrhula, was collected in March 2017 from Kushiro Natural Red-crowned Crane Reserve, Kushiro, Hokkaido, Japan. In the post-mortem examination, three adult chewing lice were obtained from the body surface. The present specimens were identified as Brueelia pyrrhularum Eichler, 1954 by morphological measurements and characteristics. This is the first record of B. pyrrhularum from Japan

A Brief Overview of Parasitic Nematodes Recorded from Waterfowls on Hokkaido, Japan

Ducks : habitat, behavior, and diseases (James Hambrick and Laurie T. Gammon, editors