母岩的特性深深影響其化育生成後之土壤性質,矽酸鹽礦物是主要的成土母岩,而這些母岩二氧化矽的含量大於65%稱為酸性岩類,二氧化矽的含量小於45%稱為超基性岩類。本論文選取台東縣池上鄉之超基性母岩(蛇紋岩)土壤與宜蘭縣大同鄉鴛鴦湖之酸性母岩土壤進行元素全量分析,研究目的旨在:(1)了解酸性與超基性母岩土壤中巨量、微量與稀有元素含量之垂直分佈情形,及(2)不同母岩土壤中各元素間的相關性。實驗結果顯示,地質背景的差異會造成各種元素在母岩中的分佈不均勻,尤其母岩性質對土壤微量元素含量的影響常扮演重要角色。蛇紋岩土壤中矽(Si)、鋁(Al)、鈦(Ti)、鍶(Sr)、鋇(Ba)、鉛(Pb)、錫(Sn)、銅(Cu)、銣(Rb)、釔(Y)、鎵(Ga)與酸性母岩土壤中鈦(Ti)、鎳(Ni)、鉻(Cr)、錫(Sn)均高於地殼的平均含量。蛇紋岩土壤中鎂(Mg)、鋁(Al)、鈣(Ca)、鐵(Fe)、錳(Mn)、鎳(Ni)、鉻(Cr)、銅(Cu)、釩(V)、釔(Y)、鎵(Ga)含量高於酸性母岩土壤,而矽(Si)、鉀(K)、鈦(Ti)、鍶(Sr)、鋇(Ba)、鉛(Pb)、鋅(Zn)、錫(Sn)、銣(Rb)的含量低於酸性母岩土壤。蛇紋岩土壤中的鉻與鎳量最大值高達4000 mg/kg,其與Mg、Fe、Sr相關係數更高達0.75以上,顯示Ni、Cr的高含量可能和此三種元素有很大的關連,值得進一步探討。
Soil properties are deeply affected by the parent rocks such as levels of major, trace, and rare elements. Silicate minerals is the major part in parent rocks. The silicon dioxide's content is bigger than 65% to be called the acidic rocks, and the silicon dioxide content is smaller than 45% is called the ultramafic rocks. This study is to analyze the soils derived from ultramafic rocks (serpentinites) and acidic rocks. The aims of this work are to: (1) understand the status of vertical distribution of the major, trace and rare elements in the study soils, and (2) correlate the relationships between major, trace and rare elements in the soils. Results indicated that type of parent rock played an important role in affecting the content of trace elements in the soils. The average concentrations of Si,Al, Ti, Sr, Ba, Pb, Sn, Cu, Rb,Y and Ga in the serpentinitic soils and Ti, Ni, Cr and Sn in the soils from acidic rocks are higher than those on the crust of Earth. However, Mg, Al, Ca, Fe, Mn, Ni, Cr, Cu, V, Y and Ga in the serpentinitic soils are higher than those in the soils from acid parent rocks. The maximum level of Cr and Ni is over 4000 mg/kg and the correlation of Cr and Ni with Mg, Fe, Sr is up to 0.75, indicating the high contents of Ni and Cr corresponded to the three elements.