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对南海4个典型断面(18°N,10°N,6°N,113°E)75个表层沉积物的稀土元素地球化学进行分析,结果表明:大部分沉积物具有相对较低的稀土元素(REE)含量(平均∑REE为128 ppm)、高的轻重稀土比(LREE/HREE)、弱的Ce负异常和中等Eu负异常,REE关键参数的变化主要取决于地理位置和沉积环境。∑REE与Al_2O_3含量呈明显的正相关,而与CaO呈明显的负相关。陆源和生物碳酸盐源是本区沉积物的两个主要来源。较低的Eu/Eu*和(Gd/Yb)N比值以及类似上地壳的REE配分模式,表明本区沉积物的源岩主要为后太古宙的长英质岩石。东部次海盆比西南次海盆的沉积物具有更低的LREE/HREE比值和更高的Eu/Eu*比值,指示有年轻火山岩(如吕宋岛弧等)产物带入到南海东部和南海东北部海域。
The REE geochemistry of 75 surface sediments at 4 typical sections (18 ° N, 10 ° N, 6 ° N, 113 ° E) of the South China Sea are analyzed. The results show that most of the sediments have relatively low rare earth elements (REE) (average ΣREE is 128 ppm), high LREE / HREE, weak negative Ce and intermediate Eu negative anomalies. The key parameters of REE vary greatly depending on the geographical location and depositional environment. ΣREE and Al_2O_3 content showed a significant positive correlation with CaO was significantly negatively correlated. Terrestrial and biogenic carbonate sources are the two major sources of sediment in this area. The lower Eu / Eu * and (Gd / Yb) N ratios and REE distribution patterns similar to the upper crust indicate that the source rocks of the sediments in this area are predominantly felsic rocks of the late Archean. The sediments in the eastern sub-sea basin have a lower LREE / HREE ratio and a higher Eu / Eu * ratio than those in the southwestern sub-sea basin, indicating that young volcanic rocks (such as the Luzon arc) are brought into the east of the South China Sea and northeast of the South China Sea Sea.