Journal of Geography (Chigaku Zasshi)
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
Volume 103 , Issue 1
Showing 1-13 articles out of 13 articles from the selected issue
  • Y. K. BENTOR
    1994 Volume 103 Issue 1 Pages 1-15
    Published: February 25, 1994
    Released: October 13, 2010
    JOURNALS FREE ACCESS
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  • Kazuharu MIZUNO
    1994 Volume 103 Issue 1 Pages 16-29
    Published: February 25, 1994
    Released: October 13, 2010
    JOURNALS FREE ACCESS
    The retreat process of Tyndall Glaciers and the vegetation were surveyed in Mount Kenya (5, 199m). Tyndall Glacier have retreated since early in this century and is retreating at an average rate of 2.88m/yr in the last 35 years. The first colonist of new till is Senecio keniophytum, which occurs at a distance of 18m from the 1992 ice-front. The speed of advance of this plant (1958-1984.2.65m/yr, 1984-1992: 2.13m/yr) is similar to the retreat rate of the glacier. The next species encountered is Arabis alpina, at 37m. This species advance at rate of 4.38m/yr (1958-1984), 4.63m/yr (1984-1992). Moss and lichen are next, at 70m and its speed of advance is 3.47m/yr. The species growing near ice-front of Tyndall Glacier advance in connection with retreat of the glacier. The species growing at distance over 100m from ice-front colonize irregularly independently of retreat process of the glacier.
    Till age and stability of land surface are important environment factors controlling vegetation pattern around Tyndall Glacier. Till age is affected by the glacial fluctuation. Stability of land surface is governed by particle-size of surface materials. Former climatic condition affects both glacial fluctuation and particle-size of surface material, and landform controls particle-size of surface material. On new till, plants is restrained from colonizing because of poor soil condition even if the slope is stable. Species growing on such slope are restricted to a few species, as Senecio keniophytum and so on, and vegetation coverage is low. On old till, environmental factors affecting both vegetation coverage and growing species are stability of land surface governed by particle-size of surface materials. On stable slope covered by big debris, vegetation coverage is high and such large plants as Senecio keniodendron, Lobelia telekii and so on are distributed. Slope covered by fine-rubble is unstable and shows low vegetation coverage by the effect of needle ice creep and solifluction because diurnal range of temperature is large.
    Although time of snow release is important environment factor governing alpine vegetation pattern in Japan because of heavy snow in winter, that is not very important factor for Mt.
    Kenya without enough snow. Wind is not very important factor because wind in Mt. Kenyais not strong. Environment of Mt. Kenya is similar to that of alpine wind-blown slope of high mountains in Japan, because both Mt. Kenya and alpine wind-blown slope in Japan don't have enough snow which work for repression of thermal fluctuation. Therefore, stability of land surface affected by particle-size of surface materials, which is important environment factor controlling vegetation pattern on Japanese alpine wind-blown slope, is important factor for alpine vegetation pattern in Mt. Kenya.
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  • Kohsaku ARAI
    1994 Volume 103 Issue 1 Pages 30-48
    Published: February 25, 1994
    Released: October 13, 2010
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    With the purpose to envisage depositional systems of the temperate shelf carbonates with respect to sea level changes in a tectonically inactive region, eight sedimentary facies (facies A to H) are differentiated in a sedimentary sequence which occurs within the Jan Juc Formation (Late Oligocene to Early Miocene) along the sea cliff at Torquay area, southern Australia. The sequence ranges from 1 to 6m in thickness and over 3.5 m.y. in duration and their spatio-temporal relationship is restored.
    While the lower sequence boundary (25.5Ma) formed during a lowstand period varies basinward from karstified surface into a conformable surface within the heavily burrowed beds, the upper sequence boundary (22Ma) is traced along just below the well-indurated “Bird Rock Cap (BRC)”, which was deposited during the subsequent lowstand period.
    The sequence is unevenly divided into two packages of sediments by MFS (maximum flooding surface), which is traced within the interval less than 1m above the shell bed (facies E); the thick TST (transgressive systems tract) below MFS and the less developed HST (highstand systems tract) above it. The TST sediments of especially very fine packstone-mudstone of which fossils are largely made up of benthic foraminiferal tests and shell fragments (facies C) are best developed, onlapping onto the lower sequence boundary. The transgressive lag characterized with profusion of glauconitic minerals and shell fragments of gravel size (facies A) occurs basinward just above the sequence boundary. Sediments of the HST are mainly composed of fine packstone with bivalve fragments and benthic foraminiferal tests (facies F) and relatively thin as progradation took place only landward.
    It is concluded, therefore, that the most salient characteristic of the temperate carbonate depositional systems for a complete cycle of sea level change is low influx of sediments at early transgression and highstand periods, as evidenced by grain composition, especially abundance of glauconitic minerals, and difference in thickness between the TST and HST.
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  • Itsuro OSHIRO
    1994 Volume 103 Issue 1 Pages 49-63
    Published: February 25, 1994
    Released: October 13, 2010
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    A new fossil assemblage of terrestrial vertebrates was found from limestone breccias, forming a cave deposit in the Futenma-gu (Shrine) Cave, Ginowan City, Okinawa (long., 26°17′19.5″;lat., 127°46′44.2″).The site represents one of the well preserved and most fo ssiliferous localities of terrestrial vertebrates in Ryukyu Islands. The assemblage of the Futenmagu site consists of the following species. Mammalia: Cervus astylodon, Dicrocerus sp. and Chiroptera; Amphibia and Reptilia: Testudo sp. nov., Geoemyda spengleri japonica , Japalura sp. And there are a few species of Ayes. As the good majority of the fossil bones be-longs to deer, it was attempted to estimate the number of individuals of each species of the fossil deers by canine teeth and axes; minimum of 67 individuals of Cervus astylodon and 133of Dicrocerus sp. were counted. This assemblage records the first fossil locality of Geoemyda spengleri japonica in Okinawa-jima and an addition for Tesudo sp. nov. in Ryukyu Islands. The species composition of the Futenma-gu assemblage is characterized with the abundance of Cervus astylodon and Dicrocerus sp . and the lack of Sus sp. and Diplothrix legata, so that it is tentatively correlated with the Yamashita-cho Daiichi Cave assemblage (Naha, Okinawa) of 32, 000 ± 1, 000y.B.P.in radiocarbon age. It is suggested that fossil land tortoises were introduced into the Ryukyu Islands earlier than hitherto presumed.
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  • Hisato SAKAI, Kazuhiko MIURA, Kiyoshi NAKANISHI
    1994 Volume 103 Issue 1 Pages 64-67
    Published: February 25, 1994
    Released: October 13, 2010
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  • Naoto KOIWA, Tsutomu SODA
    1994 Volume 103 Issue 1 Pages 68-76
    Published: February 25, 1994
    Released: October 13, 2010
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  • Teiji WATANABE
    1994 Volume 103 Issue 1 Pages 77-83
    Published: February 25, 1994
    Released: October 13, 2010
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1994 Volume 103 Issue 1 Pages 84-87
    Published: February 25, 1994
    Released: October 13, 2010
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  • 1994 Volume 103 Issue 1 Pages 93
    Published: 1994
    Released: October 13, 2010
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  • [in Japanese]
    1994 Volume 103 Issue 1 Pages plate1-plate2
    Published: February 25, 1994
    Released: October 13, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1994 Volume 103 Issue 1 Pages plate3-plate5
    Published: February 25, 1994
    Released: December 22, 2010
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  • [in Japanese], [in Japanese], [in Japanese]
    1994 Volume 103 Issue 1 Pages plate6
    Published: February 25, 1994
    Released: December 22, 2010
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  • [in Japanese]
    1994 Volume 103 Issue 1 Pages plate7-plate8
    Published: February 25, 1994
    Released: December 22, 2010
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