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为了明确珠江口盆地白云北坡纵向上沉积物物源的演化过程,以P1井泥岩的主量元素、微量元素和稀土元素测试数据为基础,采用数值对比和图版判别的方法对珠海组、珠江组及韩江组沉积时期的物源属性、构造背景和古气候条件进行了研究,认为白云北坡沉积物物源区构造背景以被动大陆边缘为主,但在珠江组上段、韩江组时期沉积物物源受活动大陆边缘的影响.结果表明:在K_2O/Na_2O-SiO_2/Al_2O_3图解中,白云北坡泥岩样品点主要落在被动大陆边缘区域,珠江组上段、韩江组有少量样品点落在活动大陆边缘区域;在La-Th-Sc图解中,泥岩样品点主要落在大陆边缘区域;泥岩的δCe值均介于1.03~1.13之间,平均值为1.09.珠海组沉积时期以附近华南花岗岩为主,珠江组下段沉积时期以华南地块古老的沉积岩钙质泥岩为主,而珠江组上段、韩江组沉积时期以云贵高原滇桂交界区碱性玄武岩为主.物源区整体处于湿热的气候条件,但珠海组、珠江组下段沉积时期湿热程度较高,化学风化程度较强,而珠江组上段、韩江组沉积时期湿热程度较低,化学风化程度较弱.
In order to clarify the evolution of sedimentary source in the longitudinal direction of Baiyun northern slope in the Pearl River Mouth Basin, based on the test data of main elements, trace elements and rare earth elements of P1 mudstone, numerical comparison and plate discrimination were used to analyze the evolution of sediment source in Zhuhai Formation, And the sedimentary provenance, tectonic setting and palaeoclimate of the Hanjiang Formation during the depositional period. It is concluded that the tectonic setting of the sedimentary provenance in the northern Baiyun Mountain is dominated by the passive continental margin. However, during the upper reaches of the Pearl River Formation, The source of the sediments is affected by the active continental margin.The results show that the mudstone samples on the northern slope of Baiyun Mountain mainly fall on the margin of the passive continental margin in the K 2 O / Na 2 O-SiO 2 / Al 2 O 3 diagram, while the upper part of the Pearl River Formation and the Hanjiang Formation have a few sample points In the La-Th-Sc plot, the mudstone samples mainly fall on the margin of the continental margin. The δCe values of mudstone range from 1.03 to 1.13, with an average of 1.09. During the sedimentation of Zhuhai Formation, South China granite, the Pearl River Formation sedimentary period to southern China ancient sedimentary calcareous mudstone based, and the upper reaches of the Pearl River Group, Hanjiang Formation deposition period to Yunnan-Guizhou Plateau border junction of alkaline The main source area is in the hot and humid climatic conditions, but the lower the Zhuhai Formation, Zhujiang Formation depositional period of higher humidity, chemical weathering is stronger, while the upper reaches of Zhujiang Formation, Hanjiang Formation depositional period of low heat and humidity, Chemical weathering is weak.