Size-frequency distribution and mode of occurrence of a Late Cretaceous inoceramid bivalve Inoceramus hobetsensis NAGAO & MATSUMOTO, 1939 were examined. A large number of samples, all of which were recovered from the Upper Cretaceous of the Tappu area, northwestem Hokkaido, show chronological change in the size-frequency distribution pattern. The proportion of the frequency of relatively small individuals (20–40 cm in size) tends to increase toward the upper sequence of the range of this species. The relative frequency of huge individuals (60–80 cm in size) also increases in the upper part, although the mode of fossil occurrence indicates that the size-frequency distribution might be biased by post-mortem taphonomic processes. The result of this study suggests change through time in the characteristics of the growth curve and/or mortality of this species.

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The Ryoke metamorphic rocks along the Mechan Tectonic Line in the Misakubo area connsist of fine-grained gneisses, migmatitic granites and mylonitic rocks. The fme-grained gneisses are pelitic, psamitic and silicious. The migmatitic granites are leucocratic, and occur as veined or dykelike forms ranging from a few centimeters to several tens of centimeter in the fine-grained gneisses. These rocks were metamorphosed under the moderate to higher temperature part of the amnphibolite facies. The mylonitic rocks are close to the Mechan Tectonic Line and consist of mylonitized finegrained gneisses, K-feldspar porphyroblast mylonite gneisses and mylonitized diorite or quartz diorite.
We present the obliquities of 113 K-feldspars from the migmatitic granites and K-feldspar porphyroblast mylonite gneisses. From the obliquities of K-feldspars , two events can be recognized in the metamorphic process : in the first event, monoclinic K-feldspars (types I and II) were formed by regional metamorphism related to migmatization, and triclinic K-feldspars (types IV and V with mean Δ value of 0.83) formed successively by retrogressive dislocation metamorphism closely related with the formation of the Mechan Tectonic Line. The incompleteness of inversion of K-feldspars in the latter might suggest faster upheaval of the metamorphic rocks in the area in comparison with those in the northeastern part of the Hida metamorphic belt.
The obliquity study of K-feldspar grains from the K-feldspar porphyroblast mylonite gneisses shows that different grains within one rock specimen have different obliquities. The detailed investigations of 3–5 mm size K-feldspar for a large single crystal reveal that the inversion of monoclinic to triclinic K-feldspar occurs at random in a single grain unlike the suggestion by TOURET (1967) that in a single grain it takes place systematically from the core towards the periphery of the porphyroblast.

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We report 26 radiocarbon age data using the benzene liquid scintillation method developed at Shizuoka University by FUKUHARA et al. (1995).
Benzene was synthesized from the plant leaves, modern land-snails (shells and bodies), fossil land-snail shells, coral, wood, charcoal (Mt. Omuro) and a carbonate chimney (Mariana).
The ¹⁴C activity was measured using a low background liquid scintillation counter (Aloka LSC LB-1) at the Radiocarbon Research Institute of Shizuoka University. β⁻-rays were counted with a window width 150-550 which regulated by TAKAHASHI (1996 MS). All samples were counted in turn, each for 20 minute and repeated 50 to 151 times in order to moniter the counter stability and obtain sufficient counts for statistical error estimation.
Correction for δ¹³C value was carried out. The standard used was NIST oxaric acid SRM 4990C, and the half-life used to calculatc the ¹⁴C age (yr. B.P.) was based on Libby’s half-life (5,568 yr).
The ¹⁴C age anomaly of modern land-snail shells in Kikai Island for Phaeohelix phaeogramma were 250–1060 yr. And 710 ± 160 yr. B.P. for Acusta despecta kikaiensis.
We could not determine the ¹⁴C age anomaly for Cyclophorus kikaiensis.
The ¹⁴C age of charcoaled wood collected from the immediately beneath the lava flow of the Omuro Volcano was the first report of 3,710 ± 95 yr. B.P.

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Changes in the tilt of the Udo Hill is related with large scale gravity collapse along the active Kusanagi Fault and subduction of the Philippine Sea Plate. Automatic laser ranging is carried out to monitor the activity of the Kusanagi Fault at 10 minutes intervals. Automatic adjustment of the refracted laser path is accomplished by using a step motor to make fine adjustments on the vertical axis. The refraction of laser path has been measured continuously since March 18, 1998. The atmospheric behavior during heating and cooling is analyzed from data on the refraction of the laser path and differences between the laser path temperature and surface air temperature. The diurnal cycle of the atmospheric behavior can be divided into 9 stages. The activity of the Kusanagi Fault is discussed, based on the selected data of laser ranging since 1995, concerning the atmospheric structure of temperature.

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