巻号一覧
23 巻, 1 号
選択された号の論文の5件中1～5を表示しています
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Pujing Pan, Nicholas J. Susak1989 年 23 巻 1 号 p. 1-10
発行日: 1989年
公開日: 2008/04/08
ジャーナル フリーA simple flow-system was designed to study the dissolution of cobaltous oxide (CoO) at surface conditions (25° and 39°C, one atmosphere). Experiments were carried out using solutions with salinities less than 0.01m and pH's of 0.7-3.46. The dissolution was found to be controlled by surface reactions and has a reaction order of 0.67±0.05 with respect to hydrogen ion concentration. The integrated kinetic equation has the form [Co(H2O)62+] =k+/k- [H+]0.67(1-e-Ak_t) where k+ and k- are reaction rates for the forward and reverse reactions, and were determined to be 1.05±0.26×10-10 m-2s-1 and 7.25±1.20×10-10 m-2s-1 respectively. CoO is not stable in acidic aqueous solutions under surface conditions. It gradually transforms into cobalt spinel (Co3O4) and which is effectively insoluble under our experimental conditions. A rate constant of 0.0038 day-1 was estimated for the phase transition reaction (CoO→Co3O4) assuming a first-order reaction model.抄録全体を表示PDF形式でダウンロード (3028K) -
Frances G. Waters, Anthony J. Erlank, Leon R. M. Daniels1989 年 23 巻 1 号 p. 11-17
発行日: 1989年
公開日: 2008/04/08
ジャーナル フリーA rare kimberlite mantle xenolith displaying a direct contact relationship between a MARID rock and metasomatised peridotite is described. There is an abrupt textural transition from a MARID (phlogopite-K-richterite-diopside) portion, to a 2 cm rind of peridotite (olivine pseudomorphs-phlogopite-K-richterite-diopside-chromite). Small, but significant differences in mineral composition exist across the boundary, the most important of which are lower Fe/Mg ratios in the peridotite rind. Our interpretation is that MARID magmas crystallised and expelled fluids which metasomatised surrounding peridotite wall-rock, and the xenolith has sampled a cumulate-wall-rock contact of this nature.抄録全体を表示PDF形式でダウンロード (1907K) -
Anthony Hall1989 年 23 巻 1 号 p. 19-23
発行日: 1989年
公開日: 2008/04/08
ジャーナル フリーSpilitic alteration increases the ammonium content of basaltic rocks. A series of spilitic rocks from southwest England was found to contain an average of 54 ppm of ammonium ion. Most of this ammonium is fixed as an isomorphous constituent in feldspars and micas, but a small proportion (averaging 5 ppm) is held in an exchangeable form. Subduction of oceanic crust containing ammonium-enriched igneous rocks may be a mechanism for recycling atmospheric nitrogen back into the mantle.抄録全体を表示PDF形式でダウンロード (1444K) -
Shunso Ishihara, Shigeru Terashima1989 年 23 巻 1 号 p. 25-36
発行日: 1989年
公開日: 2008/04/08
ジャーナル フリーRepresentative magnetite-series (n=75) and ilmenite-series (n=143) granitoids, and metamorphic rocks (n=11) from the Ryoke Belt, Sanyo Belt, Sanin Belt, Hidaka Belt, Outer Zone of Southwest Japan and Green Tuff Belt, were analyzed for total and noncarbonate carbon contents by combustion and infrared absorption photometry. Noncarbonate carbon contents of the ilmenite-series granitoids (58 and 61 ppm in the average for granodiorite and monzogranite, respectively) are slightly higher than those of the magnetite-series granitoids (39 and 35 ppm), especially of the sodic type (13 ppm for tonalite). Some ilmenite-series granitoids have noncarbonate carbon contents as high as 200-300 ppm at few places. In the carbonate vs noncarbonate carbon contents diagram, common ilmenite-series granitoids have values between those of the sodic granitoids and metamorphic rocks indicating that the ilmenite-series granitoids were formed by mixing of both the igneous and sedimentary source materials. A rather ambiguous separation of the magnetite series from the ilmenite series in these contents may also be due to remobilization of carbon after the granitoids solidified.抄録全体を表示PDF形式でダウンロード (2929K) -
Yong-Fei Zheng1989 年 23 巻 1 号 p. 37-43
発行日: 1989年
公開日: 2008/04/08
ジャーナル フリーThe three-dimensional method is described for treating U-Pb isotopic data obeying a two-stage evolution. The U-Pb discordia plane model and the Pb-Pb isochron plane model are developed respectively, to eliminate the effect of the unknown common lead correction. Calculation formulae of best-fit plane parameters are given and some examples from the literature are recalculated to demonstrate the applicability of the method. The plane-fitting can be a convenient means in U-Pb dating.抄録全体を表示PDF形式でダウンロード (1723K)
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