臺灣紅黃色灰化土生成之研究 (I)石牌粘土之礦物性質研究

Abstract

1.石牌粘土為本省北部山地最普遍之氣侯性土壤，一一黃色灰化土，本研究之目的，在研究該型土壤之粘土礦物成分，以為該土壤之生成及實用上應用之參考。 2.試驗之項目包括X光分析，示差熱分析，熱重量分析及數種化學性之分析，如 PH 有機質，游離鐵及陽離子可交換能量等。 3.試驗結果，詳列如表1、2、3、4、5及圖1、2、3等。 4.根據石牌粘土剖面形態，與機械成分，則A2層頗顯，質地B層亦然，初步鑑定謂為黃色灰化土。 5.從粘粒部分之粘土礦物成分討論，以其含高嶺石成分不高，且白雲母與石尚存留大部，顯示本剖面之風化尚淺。 6.由形態與機械成分鑑別之A2層就其全土壤之化學成分中之有機質與粘粒部分之游離鐵含量言，則該兩項成分仍高，顯示灰土化作用之淋洗或漂白作用係尚在初期。 7.本報告僅限於粘土礦物成分與三、四項理化性質，對黃色灰化土之生成研究，因未能作充分之闡釋，有待進一步多採土樣與研究其他理化性質之必要。 1.The Shih-pai clay is the most common soil of hilly land in the northern part of Taiwan. The purpose of this study is to want to know the clay mineral composition of this soil type for the reference of the genesis and practical use of it. 2. Items of this experiment consist of X-ray analysis, thermal differential analysis, ther-mogravimetric analysis and some chemical analyses which include pH, organic matter, free iron oxide and cation exchange capacity. 3. The results are showing on the tables 1,2,3,4,5, and the figures 1,2,3, etc. 4. It was identified from the beginning that Shih-pai clay could be said as yellow podz olic soils base on the apparent A2 horizon from the profile morpholdgy and the argillic horizon according to the mechanical analysis. (table 1.) 5. From the view of the clay mineral composition (table 5.) of <2μ clay fraction. The weathering of these soils are apparently young, because of that the knolinite content is not high and large part of muscovite and vermiculite are still remained in the solum. 6. The A2 horizon that had identified base on the morphology and mechanical analysis was not clear due to its high content of organic matter and free iron oxide. (table 4.) So that the podzolization or the bleaching reaction of this soil was still in the young stage. 7. Data of this study are not enough for the interpretation of the genesis of yellow podz-olic soils due to only analyse clay mineral and few chemical and physical properties of the soils. So it is needed to collect some more soil samples and to analyes other phys-ical and chemical properties for the advance study.