著者

鹿園 直建 綱川 秀夫

出版者

The Society of Resource Geology

雑誌

鉱山地質 (ISSN:00265209)

巻号頁・発行日

vol.32, no.176, pp.479-482, 1982-12-15 (Released:2009-06-12)

参考文献数

24

被引用文献数

1

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One sample of adularia from the Hosokura Pb-Zn vein-type deposits gives a K-Ar age of 5.8±0.2 Ma. This age is quite younger than that of the host rocks (Hosokura formation) of Daijima to Nishikurozawa (early to middle Miocene).Two samples of adularia from the different veins of the Sado Au-Ag mine give the K-Ar ages of 14.5±0.5 Ma. and 13.4±0.5 Ma. These ages are 25-15 m. y. younger than those of the host rocks (Odate and Aikawa formation).Summary of the ages of the vein-type deposits and those of the host rocks in the Green tuff region previously studied, including the present data on the Hosokura and Sado deposits, suggests that almost all of the vein-type mineralization in the Green tuff region of north eastern part of Japan took place after the Nishikurozawa stage (14-16 Ma.). This implies that the ages of the vein-type mineralization were later than and/or similar to that of the Kuroko mineralization.

著者

鹿園 直建 荒川 貴之 中野 孝教

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.123, no.3, pp.323-342, 2014-06-25 (Released:2014-07-03)

参考文献数

26

被引用文献数

2 6

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Water samples (number of samples = 52) were collected from the vicinity of the southern foot of Mt. Fuji, central Japan, and were analyzed for major elements (Si, Al, Fe, Mg, Ca, Na, K, Cl-, HCO3-, NO3-, etc.) and other chemical properties (pH, EC, ORP, etc.). The results show that major element concentrations increase with decreasing elevation, particularly at a low-elevation site. In the Yoshihara area, located at the southwestern foot, anion and cation concentrations vary widely and increase from west to east. In this area, water samples with a high total concentration tend to contain a high NO3- concentration, suggesting NO3- pollution of the groundwater. By contrast, in the southeastern area, NO3- pollution was not recognized. Based on nitrogen isotopic and ionic concentration data, the high NO3- concentration in the southwestern area is considered to be due to inorganic fertilizer (e.g. (NH4)2SO4) used at tea farms. Analytical results show two groundwater flows in a high-elevation area along the Urui River and in the direction from a high-elevation site at the southwestern foot toward Susono City, and that they mix together at a low-elevation site. In the southeastern foot area, two groundwater flows derive from a high-elevation site on Mt. Fuji along the Gotenba mudflow and the Mishima lava flow. The latter groundwater mixes with groundwater derived from Ashitaka and the Hakone mountains.

著者

鹿園 直建 原田 広康 池田 則生 柏木 洋彦

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.38, no.5, pp.149-160, 2009 (Released:2009-11-26)

参考文献数

20

被引用文献数

3 3

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Dissolution kinetics model calculations were performed for the interaction between three types of basaltic rocks in Japan (Fuji and Hachijyojima fresh basalts and Kitamatsuura altered basalt) and groundwater injected CO2. Dissolution rates of the basalts experimentally determined by the authors (Shikazono et al., 2008) and database of dissolution rate constants of silicate minerals in the basaltic rocks in PATHARC (Talman et al., 2000) were used for the calculations. The results of calculations indicate that most of dissolved carbon in groundwater injected CO2 can be fixed as carbonates in long-term period. The efficiency of carbon fixation is in an order, Hachijyojima>Fuji>Kitamatsuura. But the efficiency is not so different for three basaltic rocks in the fixation of carbon in underground sequestration of CO2. It is inferred that mineral trapping of CO2 by carbonates in basalt aquifer is useful for the long-term fixation of carbon in underground sequestration of CO2.

著者

鹿園 直建

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.111, no.3, pp.360-373, 2002-06-25 (Released:2009-11-12)

参考文献数

31

被引用文献数

1

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Previous studies such as that of Meybeck (1987) estimated the CO2 flux from atmosphere to riverwater due to chemical weathering by assuming that the rate of weathering of silicate rocks and carbonate rocks is proportional to the surface areas of rocks (silicate rocks : carbonate rocks = 7 : 3). However, the dissolution rate of carbonates (calcite and dolomite) is in two to four orders of magnitude higher than silicate (feldspar). This may imply that Meybeck's and other previous approaches lead to a large uncertainty in the estimate of CO2 flux. However, their estimates are nearly similar to that of Gaillardet et al. (1999), who estimated the contribution of the weathering of silicates and carbonates to riverwater chemistry based on a large volume of analytical and runoff data of the world's 60 major rivers.The thermochemical calculation in the present study indicates that the chemistry of riverwater having a small runoff is controlled by the solubilities of calcite and Na ·Ca-feldspar (Na : Ca = 1 : 1) at atmospheric PCO2 (10 -3.5 atm) and the world-wide average riverwater chemistry plot is close to the Na ·Ca feldspar-calcite-riverwater equilibrium point. This result reasonably explains the similar estimated values of CO2 flux obtained by Meybeck (1987) and others and Gaillardet et al. (1999).The conditions for riverwater saturated with Na ·Ca feldspar and calcite were derived based on a dissolution kinetics-fluid flow coupling model and were expressed as functions of τ (residence time of groundwater) and A/M (A : surface area of mineral, M : mass of water).

著者

立脇 香奈 鹿園 直建

出版者

日本地球化学会

雑誌

日本地球化学会年会要旨集

巻号頁・発行日

vol.55, pp.26-26, 2008

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本研究では2006年から2008年に亘り、多摩川上流から河口付近までのほぼ全域において、河川水と堆積物を採取し、分析を行なった。さらに堆積物においては、抽出実験を行い、重金属元素を存在形態ごとに分別することによって、元素ごとの人為的影響の割合についての考察、検討をした。

著者

鹿園 直建 武藤 逸紀

出版者

日本地質学会

雑誌

地質學雜誌 (ISSN:00167630)

巻号頁・発行日

vol.110, no.6, pp.363-371, 2004-06-15

被引用文献数

1 2

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東濃砂岩型ウラン鉱床地域の中新世瑞浪層群の堆積岩は,湖成層である上岐累層(20〜18 Ma),海成層である明世累層(16〜15 Ma),生渋累層(5〜0.7Ma)凝灰岩質泥岩,シルト岩相よりなる.土岐累肩巾の黄鉄鉱の量は多く,自形-半自形を呈し,硫黄同位体組成は非常に高い(δ<34>^S=+10〜50‰).一方,明世累層中の黄鉄鉱は量が少なく,フランボイダル状を呈し,硫黄同位体組成は低い(-28〜-5‰).この東濃地域の硫黄同位体の特徴と大きな砂岩型ウラン鉱床を胚胎するアメリカ西部のモリソン湖成層との鉱物学的・地質学的類似性より,中期巾新世(18〜16 Ma)の瑞浪地域での堆積・続成・ウラン鉱化作用は,アルカリ条件下で生じたことを示している.土岐累層の白形-半白形黄鉄鉱の高δ<34>^S 値は,高δ<34>^S 値を持つ硫酸イオンの還元により生じたものであろう.海水が湖水に浸入し,溶液中の硫酸イオン濃度が減少し,この硫酸イオンがバクテリアにより還元され,高δ<34>^S 値の黄鉄鉱が生成したのであろう.日本海が拡大し,西南日本の時計回りの回転が起こった中期中新世に,湖水環境から海洋環境へ変化し低温から高温-乾燥気候へと変化した時に湖水環境がアルカリ条件になったと考えられる.

著者

柏木 洋彦 鹿園 直建

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.112, no.4, pp.473-488, 2003-08-25 (Released:2009-11-12)

参考文献数

85

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Climate change and variations of atmospheric CO2 during Cenozoic have been discussed by many studies. The model results for global carbon cycle and climate change are generally consistent with those of many analytical studies concerning climate events in early Cenozoic, e.g., early Eocene warming events. However, the climate events proposed by analytical studies in late Cenozoic are not wholly inconsistent with the results of the model studies, e.g., Miocene climatic optimum (warming), cooling events in Eocene/Oligocene boundary and middle Miocene (15 Ma). Many problems remain in relation to evaluating CO2 flux by hydrothermal solutions at mid-ocean ridges, island-arc, and back-arc basins in the models. Also, the discrepancy may be derived from errors in estimating weathering flux, organic carbon burial, and change in vegetation. Moreover, another greenhouse effect gas such as methane, land-sea distribution, albedo variations due to the formation of ice-sheets, and temperature distribution attributed to changes in the ocean circulation system should be considered. Recent analytical studies reveal that the CO2 level since Miocene has remained relatively low in spite of the suggested climate events in this period. The mechanism of oceanic environmental change, as well as atmospheric CO2, is especially important to elucidate climate change during Cenozoic.

著者

渡辺 寧 村上 浩康 松枝 大治 吉田 武義 水田 敏夫 石山 大三 清水 正明 木村 純一 渡邊 公一郎 今井 亮 浦辺 徹郎 鹿園 直建 林 謙一郎 実松 健造 星野 美保子

出版者

独立行政法人産業技術総合研究所

雑誌

基盤研究(A)

巻号頁・発行日

2007

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世界各地の重希土類およびインジウム鉱床の調査を実施し,ベトナム,タイ等東南アジア地域で重希土類に富む花崗岩風化殻を発見するとともに,日本,中国,ベトナム,ペルー, ボリビアでのインジウムの資源量の見積もりを行った.これらの結果,中国以外の地域でも重希土類およびインジウムの資源ポテンシャルが存在することが判明し,また鉱床成因のための必要条件が考察された.

著者

木村 進一 鹿園 直建 野原 昌人 岩井 修平

出版者

一般社団法人日本応用地質学会

雑誌

応用地質 (ISSN:02867737)

巻号頁・発行日

vol.40, no.5, pp.281-294, 1999-12-10

被引用文献数

9 5

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酸化的環境下における堆積岩中の微量・希土類元素の挙動を知ることを目的とし, 中新統女川層の頁岩, 珪質頁岩の化学的風化に伴う鉱物学的, 地球化学的変動について検討を行った.新鮮岩石の黄鉄鉱は風化岩石において消失し, 水酸化鉄が生成される.全岩中のP, Mn, Co, Ni, Cu, Mo, Pb, U, REEs含有量は, 新鮮岩石と風化岩石とで著しい組成の相違が認められる.風化岩石におけるP, V, Mo, Cr, Pb, U, REEsの減少率はFe_2O_3~*付加率が多い試料ほど少なくなる傾向が認められ, このことは風化により溶脱された微量・希土類元素は水酸化鉄に吸着され, 再び岩石に濃集することを示すのだろう.ただし, 頁岩と珪質頁岩とでは, 水酸化鉄による溶脱元素の吸着率に相違が認められる.頁岩風化岩石の水酸化鉄の元素吸着率は珪質頁岩におけるものより全般的に少ない.頁岩と珪質頁岩の鉱物組成を基に考察すると, 黄鉄鉱に富む頁岩においては, 珪質頁岩より低いpH条件で風化が進行したため, 溶存化学種と水酸化鉄の電荷的性質が変化し, それほど元素は有効に水酸化鉄に吸着されなかったと推察される.