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The field trip will focus on the radiolarian response to global catastrophic events (e.g., bolide impact, large-scale volcanism, and anoxia) recorded in Triassic and Jurassic radiolarian chert of the Mino Belt, central Japan. The radiolarian chert of the Mino Belt records the sedimentary history of an oceanic plate in the Panthalassa Ocean prior to accretion at the trench. The topics presented and discussed in the field are: (1) the end-Permian mass extinction and recovery from the event; (2) Early Triassic anoxia and subsequent recovery in the Middle Triassic; (3) paleoenvironmental changes across the Early–Late Carnian boundary (Carnian Pluvial Event); (4) collapse of marine ecosystems triggered by a Norian impact event; (5) ocean acidification at the Triassic–Jurassic boundary; and (6) Early Jurassic (Toarcian) anoxia and the formation of black chert. In addition to these topics, this trip will consider aspects of the accretion process of oceanic plate sediments during the Middle to Late Jurassic., InterRed XV in Niigata 2017 Niigata University (JAPAN) Oct/22-Oct/27, 2017

Steel concrete composite decks with concrete sandwiched between top and bottom steel plates. Placing highly flowable concrete inside therefore may produce a void between the top deck and concrete owing to the change in volume while the concrete hardens or the accumulation of air while the concrete is placed. The void may cause local damage to the pavement or top steel plate and is likely to deteriorate the durability of the deck. In order to identify the scale of void that may cause damage to steel plates, three-dimensional finite element analysis was conducted. As a result, it was found that cracking occurred at bolted connections on the top steel plate when a wheel load acted at a point at a depth of 3mm or greater where the void was larger than the spacing between bolts., 長崎大学工学部研究報告 Vol.39(72), pp.20-27; 2009

Radiolarian biostratigraphic research is done for chert-clastic sequence of the Taukha terrane in the Koreyskaya River area, Far East Russia. Three successive radiolarian assemblages have been distinguished from the lower thrust sheet of the Gorbousha unit ; they are the Xitus gifuensis, Stichomitra doliolum and Pseudodictyomitra carpatica assemblages in ascending order. The lower two assemblages are extracted from the cherty part of the section, and the youngest one is from siliceous mudstone and black mudstone. The transitional facies of chert-clastic sequence in the sheet is late Late Tithonian in age. This age is different from that in the second thrust sheet of the Dalnegorsk area which is Late Kimmeridgian to Middle Tithonian. Therefore the approach of the Gorbousha unit-bearing oceanic plate to the subduction zone ranges in age, at least, from Late Kimmeridgian to Berriasian. The difference of age in two different thrust sheets possibly indicates that the duplication of chert-clastic sequences in the Gorbousha unit resulted from successive accretion of oceanic plate., 国立情報学研究所で電子化したコンテンツを使用している。

[論文]

We describe variations of floral traits of Dryas octopetala L. along a snowmelt gradient within and among three sites : 1) the Subarctic Latnjajaure in northernmost Sweden, 2) the High Arctic Longyearbyen and 3) Ny-Alesund, Svalbard in Norway, also High Arctic. Dryas octopetala had two types of flowers, hermaphrodite flowers and male flowers, lacking any gynoecium. The frequency of male flowers was higher in late snow-melt habitats (i. e. late flowering populations) both at Latnjajaure and Ny-Alesund. Male flowers were significantly lighter in dry weight than hermaphrodite flowers; the difference was larger in the High Arctic than in the Subarctic, suggesting a higher resource limitation in male flowers in the High Arctic. Flower weight also varied among the three sites, and showed a significant difference along the latitudinal gradient both in hermaphrodite and male flowers. In the hermaphrodite flowers, the gynoecium dry weight differed among the three sites, being significantly heavier at Latnjajaure than at Longyearbyen and Ny-Alesund. As a result, the "femaleness" (gynoecium weight/androecium+gynoecium weight) showed significantly higher values at Latnjajaure than at Longyearbyen and Ny-Alesund. Thus, the floral allocation to female function in D. octopetala decreases with an increase in latitude from the Subarctic to the High Arctic. Gender variation of flowers is a size-dependent phenomenon; a positive correlation between flower size and femaleness was observed within each site.

An attempt has been made to characterize and categorize some selected vascular species in the Ny-Alesund area, Svalbard, in relation to soil moisture conditions. A total of sixty releves were established to describe the floristic structures of plant communities. At each releve site, one soil core sample in a 100ml metal container was collected to determine soil physical properties. Samples were oven-dried for 48 hours at 105℃. Moisture content was measured and soil moisture index was calculated for each releve. Based on the index, sixty releves were divided into five soil moisture classes. Throughout the sixty releves, twenty-five species of vascular plants were recognized. Of them, eleven species were selected for this study. They were Salix polaris, Oxyria digyna, Polygonum viviparum, Cerastium arcticum, C. regelii, Saxifraga caespitosa, S. cernua, S. nivalis, S. oppositifolia, Dryas octopetala, and Cassiope tetragona. These were the species that occurred in more than eleven releves out of the sixty. Their frequencies against the soil moisture classes were counted. Ecological distribution curves were constructed for the species. From the distribution pattern, especially the amplitude and the mode position on the moisture classes, the species were classified into six categories as follows, i. e., euryhygrotopic xerophyte, euryhygrotopic mesophyte, euryhygrotopic hygrophyte, stenohygrotopic xerophyte, stenohygrotopic mesophyte, and stenohygrotopic hygrophyte.

Preface: Le Tour de Mino We make the six-day-long excursion that nearly northeast-southwest traverses the central Japan. The trip starts from the Takayama area in Hida Massif, travels down to south in Mino Massif, and ends at the Neo area. The excursion focuses upon the observation and discussion of the lithology and structure of the Permian to Jurassic rocks of the Mino belt, the most thoroughly studied, Jurassic subduction-generated accretionary complex of Japan. The rocks to examine during the excursion include Permian basaltic rocks, chert, and shallow-marine carbonates, Triassic to Jurassic chert and related siliceous rocks, and Jurassic terrigenous clastic rocks. Having a Panthalassic affinity, the accreted rocks of the Mino belt could offer a unique opportunity to realize similarities and dissimilarities between the Panthalassic rocks and Tethyan rocks. We also make several stops to observe high T/P metamorphic rocks of the Hida belt with a Sino-Korean (North China) affinity, Upper Paleozoic sedimentary and volcanic rocks of the Hida-gaien belt, and Jurassic granitic rocks in Hida Massif. The Hida-gaien belt is lying between the Hida belt to the north and the Mino belt to the south. We also observe post-orogenic, Late Jurassic-Early Cretaceous fluvial-lacustrine sediments covering older rocks of the Hida and Hida-gaien belts.

第3回極域科学シンポジウム/特別セッション「これからの北極研究」11月28日（水） 国立極地研究所 2階大会議室

A vegetation-environmental relationships study, based on the concept and approach of biogeoclimatology established and developed by Krajina and his students, was conducted in Strathcona Provincial Park, British Columbia, where the vegetation showed special ecosystematic peculiarities resulting from a unique geological substratum. The purposes of the present study were, therefore, 1) to clasisify the vegetation in the park according to the methods of the Zurich -Montpellier school as modified by Krajina, 2) to analyze as many environmental factors as possible, 3) to correlate the environmental factors with the plant communities at the association level, and 4) to discover the factors that contribute conspicuously to the development of the vegetation units. A total of ninety-nine plots were established to represent the phytogeocoenoses. These plots were later grouped into associations according to their floristic homogeneity and environmental similarity. In the study area, four orders, eight alliances and eight associations with three variants were established and described. In order to obtain general information concerning climate in the study area, three weather stations and ten rain gauges were installed and maintained for the summers of 1968 and 1969. Several pebbles were identified from each plot. They were found to be predominantly basalt and its allies, and the whole area was geologically fairly homogeneous. A total of 377 soil samples were analyzed for physical and chemical properties such as soil texture, field moisture, field capacity, cation exchange capacity, exchangeable cations (Ca, Mg, Na and K), total nitrogen, carbon content, available phosphorus, and pH. Some selected samples were analyzed for iron and aluminum. Soils were generally coarse in texture; most of the soils were found to be loamy sand while some were sand and sandy loam. They were especially high in base status, reflecting the influences of the base-rich parent material. Thus, most of the soils examined were found to be Brunisols which were equivalent to "pararendzina" soils (sensu Kubiena 1953). In spite of high precipitation, Podzols were rather rare. To the environmental factors which had been measured and estimated quantitatively, one way analysis of variance was applied to detect significant differences among the five forested associations. Of twenty-two factors taken into consideration, fourteen factors were found to be significant at the 1% level, one factor at the 5% level, and seven factors were not significant. Duncan's new multiple range test was applied to the factors which were significant either at the 1% or 5% level, and the associations were grouped and ranked using the result of this test. The factors most influential on the development of the associations were selected by the multiple regression analysis. The twenty-two factors were treated as independent variables, while vegetation was processed as a dependent variable. In order to quantify the vegetation, "likeliness value" was devised and used. It is a numerical assessment signifying how likely a plot is to be a member of a certain association, based on the species significance of some selected species. A species constellation involving fifty-five species was constructed based on the Chi-square test and Cole's indices. Three assemblies of species were detected, which characterized 1) xeric and mesic habitats of the drier subzone (CWHa) as well as xeric habitats of the wetter subzone (CWHb), 2) seepage habitats of both subzones, and 3) mesic habitats of the wetter subzone. In conclusion, it became apparent that the uniqueness and complexities of the vegetation in the study area rested in the considerable intermingling of species of quite different ecological character resulting from the high base status of the soils. Because of base rich edaphic conditions, some of the calciphiles commonly occur free from their normally hygrotopic restriction. At the same time, a considerable number of acido-philes grow on humus, supported by the mor humus which is already very acid due to the strong leaching by rain water. This kind of double structure makes the vegetation particularly complex and consequently more difficult to understand. Such an understanding, however, has been made possible, using the procedures followed in the present thesis.