In this paper,it took the sedimentary bauxite of the Songgui bauxite deposit as the research object,its geochemical characteristics have been studied,and then its ore-forming materials sources as well as metallogenetic environment have been discussed.The Songgui bauxite deposit is characterized by high Al2 O3 content and highA/Sratio.In aluminum-containing rock series,the overall total REE contents are higher,with large differences among the samples,moderate Eu anomaly and more positive Ce anomaly.REE distribution patterns are tilted to the right of the weak V-shaped curve or the weak M-shaped curve,reflecting the varying degree of REE fractionation.LILE (U),HFSE (Nb,Ta) and siderophile element (Cr) are significantly enriched in aluminum-containing rock series,the remaining elements are significantly loss.Cluster analysis shows that Al2O3 is positively correlated with Nb,TiO2, REE,and Li,and their correlation is obvious.Aluminum-containing rock series are associated with black metal (Ti and V),rare earth elements,and rare metals (Nb and Li),and all of these elements can be comprehensively utilizated with Al2 O3.REE distribution pattern fornormalized aluminum-containing rock series are nearly horizontal "U"-shaped curve,the TiO2/Al2 O3 ratio of Aluminum-containing rock series (17.91) is close with the TiO2/Al2O3 ratio of underlying limestone and sandstone of Beiya Formation (26.21),illustrating that the aluminiferous rock series are closely related with the underlying limestone inBeiya Formation.Among the aluminum-containing rock series,the Becontent is low (2.23 × 10-6),Th/U ratio is medium (3.68),and Ce anomalies are more negative Ce anomalies.These characteristics indicate that the ore-forming materialsof the Songgui bauxite deposit were sourced from weathering crust,and they experienced the sedimentation transformation.Ga,Sr,Ba contents andEu/Sm ratio are low (12.71 × 10-6,43.0 × 10-6,27.9 × 10-6 and0.17,respectively),which show the continental sedimentary characteristics;Sr/Ba ratio is high (1.73),which indicates the sea facies characteristics.These geochemical characteristics indicate that the ore-forming material of the Songgui bauxite deposit was came from the weathering crust,without obvious sedimentation transformation.%笔者以松桂铝土矿床沉积型铝土矿为研究对象,研究了该矿床沉积型铝土矿的地球化学特征,进而对其成矿物质来源、成矿环境进行了研究.松桂铝土矿床以Al2 O3含量高、A/S值高为特征.含铝岩系的稀土总量总体较高,不同样品之间差别较大,具中等程度的Eu负异常,多具Ce正异常;稀土配分曲线均为向右陡倾的弱“V”或弱“M”型曲线,斜率不等,反映稀土元素分馏程度不等.含铝岩系明显富集大离子亲石元素U、高场强元素Nb、Ta和亲铁元素Cr、V、Ti,其余元素则明显亏损.含铝岩系之中伴生有黑色金属Ti和V、稀土元素、稀有金属Nb和Li,可以与Al2 O3一起综合利用.聚类分析显示,Al2 O3与Nb、TiO2、REE、Li呈正相关,相关性明显.含铝岩系灰岩标准化曲线为近水平的“U”字型曲线,含铝岩系的钛率(17.91)与下伏北衙组灰岩、砂岩的钛率(26.21)接近,说明含铝岩系与下伏的北衙组关系密切.含铝岩系的Be含量低(2.23×10-6)、Th/U中等(3.68)、多具Ce正异常,说明松桂铝土矿床来源于风化壳,后又经历了沉积作用的改造;Ga含量低(12.71×10-6)、Sr含量低(43.0×10-6)、Ba含量低(27.9×10-6)、Eu/Sm值较低(0.17),显示出陆相沉积的特征;Sr/Ba值较高(1.73),显示出海相沉积的特征;这预示着松桂铝土矿床的成矿物质来源于古风化壳,沉积作用改造不明显.
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