臺灣博碩士論文加值系統

蛇紋岩為橄欖石等超基性岩類經變質作用而成，多分佈於板塊交界處。由蛇紋岩類所風化而成的蛇紋石土壤(serpentine soils)Ca/Mg比值偏低，且含有大量鉻、鎳、鈷等重金屬，最高濃度可遠超過台灣的土壤污染管制標準。此類因地質因素所造成重金屬含量偏高之土壤，雖非人為污染所致，但一樣會影響生態環境與人體健康。另外，氣候條件與土地利用方式的差異，是影響重金屬在蛇紋石土壤中宿命的主要因素，因此本研究採取日本關西地區與台灣東部之蛇紋岩土壤共8個剖面，依化育層分析必要的理化性質，且以有效性單一試劑抽出法(single extraction)與序列萃取法(sequential extraction)測定不同型態的鉻、鎳、鈷，再以X-ray繞射及掃描式電子顯微鏡搭配能量散佈光譜儀探討這些重金屬的礦物起源，以了解溫帶與亞熱帶環境下母質風化對重金屬溶解移動的影響。研究結果指出，日本樣體因Ca/Mg比值較台灣樣體低，受風化程度較低，而所有樣體中鉻、鎳及鈷全量明顯高於非蛇紋石土壤，並且部分樣體已超過台灣的土壤污染管制標準。在型態劃分中，鉻、鎳、鈷主要被固定在礦物晶格內，故集中在殘餘態，而元素間移動性大小順序為鈷>鎳>鉻。至於重金屬的DTPA抽出方面，以鎳的含量為最高而鉻最低，與序列萃取之型態分佈趨勢差異相符，表示蛇紋岩土壤中的鉻應最不易被植物所攝取。如以台灣的有機農業土壤重金屬容許量所使用的0.1 N HCl抽出來評估，則兩個水稻田表土層中的鉻及鎳皆超出此一容許量。此外，在礦物鑑定中，能夠發現蛇紋石及常與蛇紋石化作用伴隨的礦物蹤跡。在蛇紋岩土壤中，具有鐵磁性的鎳及鈷含量越高，其飽和磁化強度也有增加的趨勢。

Serpentinites, generally found in the margin areas between tectonicplates, are derived from ultramafics like peridotites. Serpentine soils from serpentinites are characterized by low Ca/Mg ratios and large amounts of heavy metals like Cr, Ni, and Co which can be over the soil pollution control standards (SPCS) of Taiwan. These heavy metals are not produced from human activities in serpentine soils, but may have adverse effects on eco-environment and human health. In addition, climate and land uses are major factors in controlling the fate of heavy metals in the soils. This study used eight pedons from Kansai of Japan and eastern Taiwan to analyze the soil horizon properties, determine the concentations of Cr, Ni, and Co by single and sequential extractions, and explore the metal origin in the minerals by XRD and SEM/EDS. The aim is to understand the influence of parent material weathering on the soils from temperate and subtropical regions. Experimental results indicates that the Japanese pedons were low weathered compared to Taiwanese due to the low Ca/Mg ratios in the Japanese soil samples. However, total contents of Cr, Ni, and Co in all soils were much higher than other non-serpentine soils, and the metal levels in some of them were over the SPCS of Taiwan. Regarding the metal fractionation, Cr, Ni, and Co were mainly from the mineral lattices, and thus were concentrated in the residual fractions. The mobility sequence followed as Co > Ni > Cr. With respect to DTPA extractable amount, Ni was the highest and Cr was the lowest. The difference in the DTPA extraction between metals was corresponding to the results of lability evalauted by sequential extraction; however, Cr is hardly absorbed by plant. Chromium and Ni concentrations in the surface soils of two paddy pedons were over the soil quality standard in Taiwanese organic famring which was evaluated by 0.1 N HCl. Moreover, serpentine mineral groups and accessory minerals have been identified in the soils. Nickel and Co contents in the soils increased with the increase of saturated magnetic susceptibility.

目錄
摘要 I
Abstract III
誌謝 V
目錄 VI
表目錄 VIII
圖目錄 IX
第一章、前言 1
1.1 研究緣起與動機 1
1.2 研究目的 2
第二章、文獻回顧 3
2.1 重金屬自然背景含量 3
2.1.1 一般土壤自然背景含量 3
2.1.2 背景含量偏高之土壤 3
2.2 蛇紋岩土壤分佈情形 6
2.2.1 全球的分佈 6
2.2.2 台灣與日本地區蛇紋岩土壤的分佈 7
2.3 蛇紋岩礦物 9
2.3.1礦物組成及結晶構造 9
2.4 蛇紋岩土壤特性 9
2.4.1理化性質 9
2.4.2黏土礦物特性 10
2.5 土壤中重金屬結合型態分佈 10
2.5.1 重金屬於土壤中之結合型態 10
2.5.2 重金屬萃取方法 10
2.6 蛇紋岩土壤磁化強度研究 13
第三章、材料與方法 14
3.1 研究區概況 14
3.1.1 日本關西地區 14
3.1.2 台灣東部地區 17
3.2 土壤理化性質分析 19
3.2.1 物理性質分析 19
3.2.2 化學性質分析 20
3.3 重金屬單一化學試劑抽出 23
3.4序列萃取程序 24
3.5土壤礦物組成分析 26
3.5.1 XRD繞射分析 26
3.5.2 掃描式電子顯微鏡觀察 26
3.6 土壤磁化強度的量測 27
第四章 結果與討論 28
4.1 土壤樣體之理化性質 28
4.1.1 土壤物理性質 28
4.1.2 土壤化學性質 32
4.2 元素全量 38
4.3 游離性與無定型金屬元素抽出量 46
4.3.1 游離性金屬元素 46
4.3.2 無定型金屬元素 48
4.4 有效性單一試劑抽出 53
4.4.1 0.1N HCl 53
4.4.2 0.01 M CaCl2 57
4.4.3 0.005 M DTPA 60
4.5鉻、鎳、鈷之結合型態分佈 63
4.6蛇紋岩土壤礦物組成 73
4.6.1 XRD繞射鑑定 73
4.6.2 SEM/EDS 礦物鑑定 74
4.7 蛇紋岩土壤中鎳及鈷與磁性相關性 75
第五章、結論 77
參考文獻 79
作者簡介 88

表目錄
表2-1 土壤中重金屬含量(mg/kg) 3
表2-2 國內外蛇紋石土壤中鉻與鎳含量(g kg-1)之範圍 5
表2-3 有機農業土壤重金屬容許量標準 11
表4-1 供試土壤之基本物理性質 29
表4-2 供試土壤之基本化學性質 35
表4-3 元素全量 41
表4-4 供試土壤游離性與無定型金屬元素抽出量 49
表4-5 供試土壤 HCl抽出之重金屬含量 55
表4-6 供試土壤 CaCl2 抽出之重金屬含量 58
表4-7 供試土壤DTPA 抽出之重金屬含量 61
表4-8 各土壤樣體中不同結合型態之鉻含量 65
表4-9 各土壤樣體中不同結合型態之鎳含量 68
表4-10 各土壤樣體中不同結合型態之鈷含量 71

圖目錄
圖2-1 全球蛇紋岩分佈概況 6
圖2-2 台灣蛇紋岩分佈 7
圖2-3 日本蛇紋岩分佈 8
圖3-1 土壤樣體採集點兵庫縣位置圖 14
圖3-2 日本關西地區地質圖 15
圖3-3 日本關西土壤樣體剖面 16
圖3-4 台灣東部地區地質圖 17
圖3-5 台灣東部土壤樣體剖面 18
圖4-1 蛇紋岩土壤樣體pH與交換性Ca/Mg相關性 34
圖4-3 全量鎳與交換性Ca/Mg相關性 40
圖4-4 土壤樣體黏粒部份之 X-ray 繞射分析圖(C層) 73
圖4-5 Ta-6土壤薄切片之SEM影像與EDS元素分析 74
圖4-6 Ys-F3樣體21-40cm處之M-H曲線 75
圖4-7 土壤中鎳含量與飽和磁化強度相關性 76
圖4-8 土壤中鈷含量與飽和磁化強度相關性 76

陳怡君，2005，台灣東部池上地區蛇紋岩土壤中鉻與鎳之生物地質化學特徵。國立屏東科技大學環境工程與科學研究所碩士論文。第146頁。
陳肇夏，1998，台灣的變質岩。台灣的地質之十一，經濟部中央地質調查所編印。第356頁。
張英琇，2007，海岸山脈蛇紋岩土壤金屬元素之生物地質化學性質。國立屏東科技大學環境工程與科學研究所碩士論文。第113頁。
鄭光喆，2007，重金屬污染土壤之不同單一與連續性抽出方法評估。國立中興大學土壤環境科學系碩士學位論文。第75頁。
吳景翰，2009，不同施肥條件下蛇紋石土壤中重金屬之溶出特性與水稻吸收量。國立屏東科技大學環境工程與科學研究所碩士論文。第38-46頁。
郭魁士，1997，土壤學，之宜出版社。
旺　羅、劉東生及呂厚遠，2000，污染土壤磁化率特徵，科學通訊，45卷，第1091-1093頁。
Alexander, E. B., Wildan, W. E., and Lynn, W. C., 1985, Ultramfic (serpentinitic) mineralogy class, In: Kittrick, J. A. (eds.), Mineral classification of soils, Special Publication 16, Soil Science Society of America, Madison, Wisconsin, USA., 135-146.
Alexander, E. B., 1988, Morphology, fertility and classification of productive soils on serpentinused peridotite in California, Geoderma, 41: 337-351.
Alexander, E.B., Adamson, C., Zinke, P.J., Graham, R.C., 1989, Soils and conifer forest productivity on serpentinized peridotite of the Trinity Ophiolite, California, Soil Science, 148:412–423.
Alexander, E.B., Ellis, C.C, Burke, R., 2007, A chronosequence of soils and vegetation on serpentine terraces in the Klamath Mountains, Soil Science, 172: 565-576.
Allaway, W. H., 1968, Advance in Agronomy, 20:240-243.
Alloway, B. J., 1995, Heavy metal in soils, 2nd ed., Blackie Academic and Professional, Glasgow, UK.
Amir, H., Pineau, R., 1998, Effects of metals on the germination and growth of fungal isolates from New Caledonian ultramafic soils, Soil Biology and Biochemistry, 30: 2043-2054.
Baker, D. E., and Amacher, M. C., 1982, Nickel, copper, zinc, and cadmium, In: Page, A. L., Miller, R. H., and Keeney, D. R. (eds.), Methods of Soil Analysis, Part II, Chemical and Microbiological Method, Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 323-336.
Becquer, T., Quantin, C., Rotte-Capet, S., Ghanbaja, J., Mustin, C., and Herbillon, A. J., 2006, Sources of trace metals in Ferralsols in New Caledonia, European Journal of Soil Science, 57: 200-213.
Becquer, T., Petard, J., Duwig, C., Bourdon, E., Mourau, R., and Herbillon, A. J., 2001, Mineralogical, chemical and charge properties of Geric Ferralsols from New Caledonia, Geoderma, 103: 291-306.
Blake, G. R., and Hartge, K. H., 1986, Bulk density, In: Klut, A. et al. (eds.), Methods of soil analysis, Part 1. Physical and Mineralogical methods-Agronomy monograph No. 9 Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 363-375.
Bonifacio, E., Zanini, E., Boero, V., Franchini-Angela, M., 1997, Pedogenesis in a soil catena on serpentinite in north-western Italy, Geoderma, 75: 33-51.
Brady, K. U., Kruckeberg, A. R., Bradshaw Jr., H. D., 2005, Evolutionary ecology of plant adaptation to serpentine soils, Annual Review of Ecology, Evolution, and Systematics, 36: 243-266.
Brooks, R. R., Morrison, R. S., Reeves, R. D., Dudley, T. R., and Akman, Y., 1979, Hyperaccumulation of nickel by Alyssum Linneaud (Cruciferas). Proceeding of Royal Society of London. Series B, Containing papers of a Biological character, Royal Society (Great Britain), 203: 387-403.
Brooks, R.R., 1987, Serpentine and its Vegetation. Dioscorides Press, Portland.
Brooks, R. R., Reeves, R. D., Baker, A. J. M., 1992, The serpentine vegetation of Goias State, Brazil, In: Baker, A. J. M., Proctor, J., Reeves, R. D. (eds.), The Vegetation of Ultramafic (Serpentine) Soils, 7-81.
Bulmer, C. E., and Lavkulich, L. M., 1992, Morphology, chemistry, and mineralogy of soils derived from serpentinite and tephra in southwestern British Columbia, Soil Science, 154: 73-82.
Bulmer, C. E., Lavkulich, L. M., 1994, Pedogenic and geochemical processes of ultramafic soils along a climatic gradient in southwestern British Columbia, Canadian Journal of Soil Science, 74: 165-177.
Burt, R., Wilson, M. A., Mays, M. D., and Lee, C. W., 2003, Major and trace elements of selected pedons in the USA, Journal of Environmental Quality, 32: 2109-2121.
Burt, R., Fillmore, M., Wilson, M. A., Gross, E. R., Langridge, R. W., and Lammers, D. A., 2001, Soil properties of selected pedons on ultramafic rocks in Klamath mountains, Oregon, Communications in Soil Science and Plant Analysis, 32: 2145-2175.
Chaney, R. L., 1983, Potential effects of waste constituents on the food chain, In: Parr, J. F., Marsh, P. B. and Kla J. M. (eds), Land treatment of hazardous wastes, Noyes Data Corporation, Park Ridge, NJ, 152-240.
Cheng, C. H., Jien, S. H. Tsai, H., Chang, Y. H., Chen, Y. C., and Hseu, Z. Y., 2009, Geochemical element differentiation in serpentine soils from the ophiolite complexes, eastern Taiwan, Soil Science, 174: 283-291.
Chino, M., 1981, Uptake-transport of toxic metals in rice plants, In: Kakuzo, K., Yamane, I.,(eds), Heavy metal pollution on soil of Japan, Japan Scientific Societies Press, Tokyo, 81-89.
Cleaves, E. T., Fisher, D. W., and Bricker, O. P., 1974, Chemical weathering of serpentinite in the eastern Piedmont of Maryland, Geological Society of America Bulletin, 85: 437-444.
Díez Lázaro, J., Kidd, P.S., Monterroso Martínez, C., 2006, A phytogeochemical study of the Trás-os-Montes region (NE Portugal): Possible species for plant-based soil remediation technologies, Science of The Total Environment, 354: 265–277.
Dixon, J.B., 1989, Kaolin and serpentine group minerals, In: Dixon, J. B., and Weed, S.B. (eds.), Minerals in soil environments, 2nd Edition, Soil Science Society of America Book Series No. 1. Soil Science Society of America, 467-526.
Gardner, W. H., and Hartge, K. H., 1986, Bulk density, In: Klut, A. et al. (eds.), Methods of soil analysis, Part 1. Physical and Mineralogical methods-Agronomy monograph No. 9 Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 383-411.
Garnier, J., Quantin, C., Martins, E.S., and Becquer, T., 2006, Solid speciation and availability of chromium in ultramafic soils from Niquelândia, Brazil, Journal of Geochemical Exploration, 88: 206-209.
Garnier, J., Quantin, C., Guimaraes, E., and Becquer, T., 2008, Can chromite weathering be a source of Cr in soils? Mineralogical Magazine, 72:49-53.
Gambi, O.V., 1992, The distribution and ecology of the vegetation of ultramafic soils in Italy, In: Roberts, B.A., Proctor, J. (eds.), The Ecology of Areas with Serpentinized Rocks, A World View. Kluwer Academic Publishers, 17-247.
Gee, G. W., and Baude, J. W., 1986, Particle-size analysis. In: A. Klut et al. (eds.), Methods of soil analysis, Part 1. Physical and Mineralogical methods-Agronomy monograph No. 9 Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 383-411.
Ghaderian, S. M., Mohtadi, A., Rahiminejad, M. R., and Baker, A. J. M., 2007, Nickel and other metal uptake and accumulation by species of Alyssum (Brassicaceae) from the ultramafics of Iran, Environment Pollution 145:293-298.
Gough, L.P., Meadows, G.R., Jackson, L.L., and Dudka, S., 1989, Biogeochemistry of a highly serpentinized, chromite-rich ultramafic area, Tehama County, California, US Geological Survey Bulletin, 1901: 1-24.
Graham, R. C., Diallo, M. M., and Lund, L. J., 1990, Soils and mineral weathering on phyllite colluvium and serpentinite in northwestern California, Soil Science Society of America Journal, 54: 1682-1690.
Hossner, L. R., 1996, Dissolution for Total Elemental Analysis, In: Bigham, J. M. (eds.), Methods of Soil Analysis, Part 3, Chemical Methods, Soil Science Society of America Book Series No. 5, Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 49-64.
Hseu, Z. Y., 2006, Concentration and distribution of chromium and nickel fractions along a serpentinitic toposequence, Soil Science, 171: 341-353.
Hsiao, K. H., Bao, K. H., Wang, S. H., and Hseu, Z. Y., 2009, Extractable concentrations of cobalt from serpentine soils with several single-extraction procedures. Communications in Soil Science and Plant Analysis, 40: 13: 2200-2224.
Istok, J.D., and Harward, M.D., 1982, Influence of soil moisture on smectite formation in soils derived from serpentinite, Soils Science Soiciety of America Journal, 46: 1106-1108.
Johnston, W. R. and Proctor, J., 1981, Growth of serpentine and non-serpentine races of Festuca rubra in solutions simulating the chemical conditions in a toxic serpentine soil, Journal of Ecology, 69: 855-869.
Kabata-Pendias, A., and Pendias, H., 2001, Trace elements in soils and plants. Boca Raton, Fl.: CRC Press, 413.
Kabata-Pendias, A., 1993, Behavioural properties of trace metals on soils, Applied Geochemistry, 2: 3-9.
Kaupenjohann, M., and Wilcke, W., 1995, Heavy metal release from a serpentine soil using a pH-salt technique, Soil Science Society of America Journal, 59: 1027-1031.
Lee, B. D., Graham, R. C., Laurent, T. E., Amrhein, C., and Creasy, R. M., 2001, Spatial distribution of soil chemical conditions in a serpentinitic wetland and surrounding landscape, Soil Science Society of America Journal, 65: 1183-1196.
Lee, B. D., Graham, R.C., Laurent, T. E., and Amrhein, C., 2004, Pedogenesis in a wetland meadow and surrounding serpentine landslide terrain, northem Califormia. Geoderma, 118: 303-320.
Lindsay, W. L., and Norvell, W. A., 1978, Development of a DTPA soil test for zinc, iron, manganese and copper, Soil Science Society of America Journal, 42: 421-428.
Lyon, G. L., Brooks, R. R., Peterson, P. J., Butler, G. W., 1968, Trace elements in a New Zealand serpentine flora, Plant and Soil, 29: 225-240.
Massoura, S.T., Echevarria, G., Becquer, T., Ghanbaja, J., Leclerc-Cessac, E., Morel, J.L., 2006, Control of nickel availability by nickel bearing minerals in natural and anthropogenic soils, Geoderma, 136: 28-37.
Mclean, E. O., 1982, Soil pH and lime requirement, In: Page, A. L. et al. (eds.), Methods of soil analysis, Part 2. Chemical and microbiological properties, Agronomy monograph No. 9, Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 199-244.
McKeague, J. A., and Day, J. H., 1966, Dithionite and oxalate extractable Fe and Al as acids in different various classes of soils, Canadian Journal of Soil Science, 46: 13-22.
Mehra, O. P., and Jackson, M. L., 1960, Iron oxides removed from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate, Clays and Clay Miner, 7: 317-327.
Mitchell, R. L., 1955, Trace elements, In: Van Nostrand R. (esd.), Chemistry of the Soil, 253-285.
Miranda, M., Benedito, J. L., Blanco-Penedo, I., and López-Lamas, C., 2009, Metal accumulation in cattle raised in a serpentine-soil area: Relationship between metal concentrations in soil, forage and animal tissues, Journal of Trace Elements in Medicine and Biology, 23: 231-238.
Nelson, D. W., and Sommer, L. E., 1982, Total carbon. Organic carbon, and organic matter, In: Page, A. L. et al. (eds.), Methods of soil analysis, Part 2. Chemical and microbiological properties. Agronomy monograph No. 2. Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 539-577.
Noble, A.D., Hughes, J.C., 1991, Sequential fractionation of chromium and nickel from some serpentinite-derived soils from the eastern Transvaal, Soil Science and Plant Nutrition, 22: 1963-1973.
Novozamsky, I., Lexmond, T. H. M., and Houba, V. J. G., 1993, A single extraction procedure of soil for evaluation of uptake of some heavy metals by plant, International Journal of Environmental Analytical Chemistry, 51: 47-58.
Oze, C., Fendorf, S., Bird, D. K., and Coleman, R. G., 2004a, Chromium geochemistry of serpentine soils, International Geology Review, 46: 97-126.
Oze, C., Fendorf, S., Bird, D. K., and Coleman, R. G., 2004b, Chromium geochemistry in serpentinized ultramafic rocks and serpentine soils from the Franciscan complex of California, American Journal of Science, 304: 67-101.
Oze, C., Bird, D.K., and Fendorf, S., 2007, Genesis of hexavalent chromium from natural sources in soil and groundwater, The National Academy of Sciences of the USA, 104: 6544-6549
Proctor, J., and Woodell, S., 1975, The ecology of serpentine soils, Advances in Ecological Research, 9: 255-366.
Pueyo, M., Lopez-Sanchez, J. F., and Rauret, G., 2004, Assessment of CaCl2,NaNO3 and NH4NO3 extraction procedures for the study of Cd, Cu, Pb and Zn extractability in contaminated soils, Analytica Chimica Acta, 504: 217-226.
Quantin, C., Becqure, T., and Berthelin, J., 2002a, Mn-oxide: a major source of easily mobilisable Co and Ni under reducing conditions in New Caledonia Ferralsols, Comptes Rendus de l'Acadâemie des sciences, 334: 273-278.
Quantin, C., Becquer, T., Rouiller, J.H., Berthelin, J., 2002b, Redistribution of metals in a new Caledonia ferralsol after microbial weathering, Soil Science Society of America Journal, 66: 1797- 1804.
Quantin, C., Ettler, V., Garnier, J., and Sebek O., 2008, Sources and extractibility of chromium and nickel in soil profiles developed on Czech serpentinites, Comptes Rendus Geoscience, 340: 872-882.
Rabenhorst, M. C., Foss, J. E. and Fanning, D. S., 1982, Genesis of Maryland soils formed from serpentinite, Soil Science Society of America Journal, 46: 607-616.
Reeves, R.D., Baker, A.J.M., Romero, R., 2007, The ultramafic flora of the Santa Elena peninsula, Costa Rica: A biogeochemical reconnaissance, Journal of Geochemical Exploration, 93: 153-159.
Robinson, B.H., Brooks, R.R., Clothier, B.E., 1999, Soil Amendments affecting nickel and cobalt uptake by Berkheya coddii: Potential use for phytomining and phytoremediation, Annals of botany, 84: 689-694.
Schreier, H., Omuenti, J. A., and Lavkulich, L. M., 1987, Weathering processes of asbestos-rich serpentinitic sediments, Soil Science Society of America Journal, 51: 993-999.
Thomas, G. W., 1982, Exchangeable cation, In: A. L. Page et al. (eds.), Methods of soil analysis, Part 2. Chemical and microbiological properties. Agronomy monograph No. 9. Agronomy Society of American and Soil Science Society of America, Madison, Wisconsin, USA., 159-165.
Tibbetts, R. A., Smith, J. A. C., 1992, Vaculor accumulation of calcium and its interaction with magnesium availability, In: Baker, A.J.M., Proctor, J., Reeves, R.D. (eds.), The Vegetation of Ultramafic (Serpentine Soils), Intercept, Andover, England, 367-373.
Turitzin, S. N., 1982, Nutrient limitations to plant growth in a California serpentine grassland, American Midland Naturalist, 107: 95-99.
Ure, A. M., 1996, Single extraction schemes for soil analysis and related application, Science of the Total Environment, 178: 3-10.
Walker, R.B., 1954, Factors affecting plant growth on serpentine soils, In: Whittaker, R.H. (eds.), The Ecology of Serpentine Soils, A Symposium Ecology, 35: 259-266.
Wildman, W. E., Jackson, M. L., and Whittig, L. D., 1968, Iron-rich montmorillonite formation in soils derived from serpentinite, Soil Science Society of America Journal, 32:787-794.