シロバナトウウチソウは，東北地方の亜高山帯に生える日本固有種である．これまで本種の染色体数については，2n＝56と2n＝54の報告があったが，採集地あるいは調査個体数が十分に示されていなかった．本研究では，シロバナトウウチソウの染色体数を，16集団70個体について調査した．その結果，13集団59個体の植物は2n＝56の8倍体であった．一方，高松岳，

（いずれも秋田県）の2集団，計9個体の植物は，2n＝84の12倍体であった．ほとんどの集団からは一方の倍数体のみが得られたが，唯一月山では，1520m 地点から12倍体，1800m 地点から8倍体が得られた．本研究の結果，本種は8倍体，12倍体から構成されることが明らかになった．からは異数体（2n＝85）も1個体えられたが，2n＝54や2n＝85のような異数体はまれであり，偶発的に生じるものであると思われる

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The annual water balance in the Shinjo Basin was calculated by a climatological method. The Shinjo Basin, which is 205km² in area, is situated in the northern part of Yamagata Prefecture (Fig. 1) and receives abundant snowfall in winter. The drainage from this basin flows into the Sake River which is a tributary of the M ogami River.
It is said that the data of water balance components (precipitation, runoff, evaporation) of a drainage basin may contain considerable errors and that the accuracy will get worse in the order of precipitation, evaporation and runoff. So the author wanted to estimate runoff from precipitation and evaporation. Empirically, 60_??_70% of a small pan evaporation value are regarded as the actual evapotranspiration of the area. The author adopted 65% of this value in this calculation.
On the other hand, the author calculated evaporanspiration from the drainage basin by using the Penman's method for potential evaporation (Table 5). In the case of the Shinjo Basin, the actual evapotranspiration was obtained by multipling the Penman's value by the factor of 0.80 (Fig. 5). The result of water balance obtained from mean value for nine years are as follows; precipitation: 2220mm/year, evapotranspiration: 568mm/year, runoff: 1652mm/year, runoff ratio: 0.74.
Compared with the observed values in the Kamabuchi Experimental Watershed which lies about 15km to the north of this basin, the calculated ones for the Shinjo Basin shows close agreement. Consequently, the calculated runoff from precipitation and evaporation can be considered as appropriate for the Shinjo Basin.

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東北地方中央部の鬼首―湯沢マイロナイト帯の東西で変成岩を調査し、その鉱物組み合わせや鉱物化学組成を検討して比較を行った。マイロナイト帯の東側に位置する岩手県奥州市焼石岳南麓では、角閃岩、珪長質片岩、泥質片岩、弱い変成作用を受けた粘板岩、蛇紋岩がみられる。マイロナイト帯の西側に位置する山形県最上町地白川では、細粒の黒雲母片麻岩と角閃岩がみられる。焼石岳南麓の角閃岩中の角閃石は大鉢森角閃岩との間に類似性がみられる。地白川の黒雲母片麻岩中のザクロ石の化学組成は阿武隈変成帯に類似し、角閃岩中の角閃石の組成は竹貫変成岩に類似する。超苦鉄質岩中のスピネルの組成は早池峰の超苦鉄質岩中のものに似る。変成岩中の鉱物化学組成の観点からマイロナイト帯の東側は南部北上帯に属し、西側は阿武隈帯に属すると考えられる。

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本研究は, 日本列島に分布する白亜紀－古第三紀花崗岩類を対象に，それらが持つ物理定数，密度・孔隙率・磁化率・残留磁化そしてQn比（Königsberger ratio）などを系統的に集約し，花崗岩類が共通して持つ性質や，それとは逆に，各時代や地域が持つ特有の性質を明確にし，地質構造の解析や，公害や環境問題，災害予知など各方面に必要な基礎資料を提供する事を目標にとりまとめた．今回は東北地方北部を対象に570余露頭より採取した花崗岩試料の結果を集約した. 対象とした４地域は，北上山地，太平山地域，栗駒－鳴子地域そして村上地域である．その結果は以下のようである． 4地域の平均密度は2.66～2.77（ｘ１０^３ｋｇ/m ³）で村上地域が一番小さく北上山地が最も大きい. 孔隙率は0.4～0.6 ）で地域による差は殆んど認められない．磁化率は密度が2.60～2.95の変化（SiO2は約77～42（％））に対し10倍に増加する．これらの関係において磁化率はまた，上限,下限の2直線に挟まれる範囲に収まり, 4地域独自の空間を占有する．Qn比は0～0.4を示すものが圧倒的に多く, 磁気図解釈の際，残留磁化を考慮する必要はない．磁化率の低い岩石にも残留磁化を担う強磁性鉱物が存在している．

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東北地方を対象地域とし, 仙台と秋田のレーダー資料を用いて, 盛夏型気圧配置における対流性エコー発現の地域性, およびそれと地形との関係を統計的に調べた。その結果, 次のことが明らかになった。(1) 全時刻にわたるエコー発現数の総計をみると, 海抜高度が増すにつれてほぼ直線的に増加する。(2) しかし詳細にみると, エコーの発現分布は, 海抜高度分布をやや東にずらした形になっている。すなわち, 山地の東側で発現数が多く, 盆地や平野の東側では少ない。(3) エコーの発現頻度は, 大気が不安定な場合には15時に極大となるが, 安定な場合には極大が遅れ, 18時となる。(4) 海抜高度とエコー発現数が必ずしも比例しない原因としては, 風向と山地・山脈の連なる向きとの関係が, エコーの発現に大きく影響しているからと考えられる。大気が不安定なときにエコーが発現しやすい場所は, 700mb面風向に対しほぼ平行に連なる山地や山脈の上空で, 特に標高の高い山の風下側である。

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This paper deals with the relation between the geology and the growth of Cryptomeria there-on in the Kaneyama district, Yamagata Prefecture.
The surface geology of the district is classified, from agricultural and forestrial standpoints, as:
A Two Pyroxene andesite and its agglomerate with their loose decomposition products thickly developed on the surface,
B Breccia tuff and pumiceous tuff with some blocks of “A” in the overlying soil,
C Breccia tuff and pumiceous tuff with some blocks of hypersthene andesite in the overlying soil,
D Breccia tuff and pumiceous tuff without other blocks in the soil,
E Pumiceous clayey tuff, tuffaceous shale and fine clayey tuff.
The development of Cryptomeria is best on A, next on B and C, and worst on E. On D, it is assumed from few data, the development is worse than on B and C, but is better than on E.
No definite relation is found between the growth of the tree and the direction of the slope.

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The thermal history of the Onikobe geothermal system, northeast Japan, was studied, based on microthermometry of fluid inclusions in hydrothermal veins from the KR-series wells which were drilled by the New Energy Development Organization (NEDO). The hydrothermal veins are composed mainly of quartz, anhydrite and calcite with subordinate amounts of wairakite, epidote, chlorite, native sulfur and pyrite. Fluid inclusions occur in quartz, anhydrite, clacite and wairakite. Fluid inclusions of hydrothermal quartz and anhydrite in granitic rocks around the bottom of well KR-l, were formed by trapping boiling fluids. Their final melting points of ice (Tm) and homogenization temperatures (Th) range from -0.3 to -3.0°C and from 270 to 320°C, respectively. The Th's are plotted on the boiling point curve of water adjusted to the present water table (BPC). On the other hand, Th's of fluid inclusions in volcanic rocks shallower than 1200m in the borehole are plotted between the BPC and the present well temperature profile (WT). Fluid inclusions from well KR-2 are divided into two groups, based on their Th's; one's Th's plot on or above the BPC, and the other's on the WT. Th's of fluid inclusions from well KR-3 deeper than 1200m plot near the BPC, where the WT is also drawn near the BPC. Th's of fluid inclusions from well KR-4 have ranges of 40 to 80°C at each level, and the highest Th's correspond to the WT. Fluid inclusions from well KR-5 are divided into three groups, based on their Th's. Th's of group 1 are plotted above the BPC at very shallow levels, and their host rock are remarkably silicified. Those of group 2 are on the BPC, those of group 3 are between the BPC and the WT, or on the WT. The microthermometrical data of fluid inclusions and petrography of hydrothermal veins suggest that geothermal activity is still vigorous at deeper levels of the wells KR-1 and KR-3. Fluid inclusions whose Th's are different occur in the wells KR-2 and KR-5. These variations are probably reflected by a cooling process around the wells, and suggest that the geothermal activity around the wells KR-2 and KR-5 has declined. The higher WT than Th's around the well KR-4 suggests that fluid inclusions of lower Th's than the WT were formed in a past stage of lower temperatures, and that geothermal activity around the well is possibly high.

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