Ion exchange adsorption on H⁺-form smectite was investigated on the bases of statistical thermodynamics and electron diffraction. Smectite was converted initialy to H⁺-form by electrophoresis. Electron diffraction method showed no differences on the respective unit cell dimensions for both H^--form smectite and raw smectite, which indicates that no removal of octahedral and tetrahedral cations took place in the H⁺-form smectite. Ion exchange isotherms of H⁺-form smectite were obtained by conductmetric method for Na⁺, Li⁺ and Ca⁺⁺ at 25°C.
For exchange adsorption on an energiticaly uniform lattice, isotherm equations were derived by the use of statistical thermodynamics. The equations closely coinside with the experimental adsorption isotherms. Applying these equations to the experimental datas, the potential energies for the ion exchange adsorption and the interaction energies of ion pairs are obtained. The interaction energies of ion pairs are-1.14kT, 0.69kT and + 1.00kT for Na⁺-H⁺, Li⁺-H⁺ and Ca⁺⁺-H^- pair, respectively. Calculating the free energies of ion exchange, the state of hydrated H-ions in the interlayer space was discussed.

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The Yano-Shokozan pyrophyllite deposits occur in acidic volcanic rocks of the late Cretaceous age. Dacitic to rhyolitic rocks are widely distributed in the Yano-Shokozan area, and those rocks are divided into by three units as Lower, Middle, and Upper units which can be correlated to the Takada rhyolitic rocks. The Lower unit mainly consists of acidic tuff with intercalated lithic lapilli, pumice and thinly bedded tuff in ascending order. The Middle unit is further divided into two layers as “a” and “b”; the former is composed of acidic lava, vent lapilli tuff, acdic tuff, and spherulitic tuff, the latter is made up of medium bedded tuff, acidic tuff with intercalation of lapilli tuff and fine tuff, spherulitic lava and thinly bedded tuff. The Upper unit, consists of alternative shale and tuffaceous sandstone, and rhyolitic tuff. The Middle unit is about 270 meters thick and has undergone extensive hydrothermal alteration. Two horizons of pyrophyllite deposits were recognized in this Unit by volcano-stratigraphic study. The main orebodies of the Yano-Shokozan Mine are the Nishiyama, Nishiyama-higashi, Nishiyama-minami, Takinotani, Hagiwaraguchi, Sashikawa, and Nakayama orebodies. The first three occur in the pyroclastic rocks of the “a” layer of Middle unit, while the last four occur in lacustrine sediments of the “b” layer of the Middle unit. Pyrophyllite deposits which are intimately related to bedded tuff of lacustrine origin. They tend to occur as the layers just above the bedded tuff and as the layers intercalated between two bedded tuffs.

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Diagenetic clinoptilolite, heulandite and analcime are present in the marine silicic tuffs and tuffaceous rocks in the MITI-Toyokoro, Kesennumaoki, and Nishitsugaruoki boreholes. The chemical analysis, SEM and petrographic microscope observation show the mechanism of clinoptilolite to analcime or heulandite transformation.
The composition of clinoptilolite do not modified by cation exchange during burial. But at the depth of transformation of Na-K-type clinoptilolite to analcime at the MITI-Toyokore borehole, Na-K-type clinoptilolite is changed into Na-type clinoptilolite, which is an intermediate phase, by cation exchange reaction. The Na-type clinoptilolite begins to dissolve at higher depths and shows the hopper crystal shape near euhedral analcime crystals in same volcanic glass shard. The clinoptilolite to analcime transformation is the microdissolution-precipitation mechanism, which is stimulated by the increase of the temperature with increasing burial depth and probably by the increase of Na ion ratio in pore water.
At the transformation depth of clinoptilolite to heulandite at the MITI-Kesennumaoki borehole, Na-K-clinoptilolite reacts with Ca-rich pore water to precipitate Ca-type clinoptilolite. The etch hillock, typical surface texture of the dissolving crystal, is observed on Na-K-clinoptilolite. Ca-type heulandite overgrows on Ca-type clinoptilolite progressively. The Ca-type heulandite which is found below transformational depth has a compositional zoning which consists of Ca-type clinoptilolite core and Ca-type heulandite rim.
The exceptionally K-rich clinoptilolite and heulandite are found from the MITI-Nishitsugaruoki borehole. The crystal size and density of this group of zeolite changes larger and coarser below the depth heulandite appears. Heulandite shows zonal structure similar to that found from the MITIKesennumaoki borehole, but both clinoptilolite core and heulandite rim found in the MITINishitsugaruoki borehole are exceptionally rich in K. The transformation mechanism of K-type clinoptilolite to K-type heulandite may not be a cation exchange reaction but a microdissolutionprecipitation mechanism.

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(1) 薄層組織は学際的な研究対象であって, 根本問題を抱えている.それは周期性発現の究極の起原と原始状態はなにか?, ということである.この点に焦点を合わせて, 研究史の足跡を辿ると, コンクリーションおよび関連物の薄層組織の問題に関心事が多いので解説した.
(2) 順序として, 薄層組織全般の問題の要点を総論として述べた.
(3) コンクリーションおよび関連物の薄層組織研究史の要点を紹介した.
(a) 外因として, 環境リズムを遠因とする成長線が, 生体石灰化組織の中で理解され, 内因として, リーゼガング環が知られたが, ともに主流の考えにならず, 意見が交錯した.
(b) 古くから, コアセルベート, ゲル,「エマルソイド」の, 球粒析出→ 連結→一部合体→ 完全合一→結晶化のイメージが描かれていた.その後も,「コロイド」という言葉を交えた意見が交錯し, 多くの未解決の問題を今日に残しているという実情が示された. 以上は本篇の要旨である. この「コロイド観」の背景と裏づけについての筆者の視点を後篇で述べる予定である.

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