【摘要】 本文对位于南海西部深海平原的SA14-34岩心进行详细的沉积物组分研究,结果表明:该岩心岩性复杂多变,沉积了粘土、粉砂质粘土、砂质粘土、粘土质粉砂、砂质粉砂、砂和粉砂质砂等7种沉积物类型。浊流沉积发育,至少已识别出4个特征明显的浊流层。浊流层厚度为18～120 cm,具有粒度较粗呈下粗上细、异地钙质微体生物化石丰富、陆源碎屑矿物含量高、SiO₂/Al₂O₃比值和CaCO₃含量高四大特点。并对浊流沉积的物质来源、成因进行了初步分析,认为浊积物主要来自西部陆架-陆坡区,有利的地形、丰富的物源和频繁的海底火山活动诱发的地震是浊流发生的主要原因。更多还原

【Abstract】 Results based on visual core description,smear slide,microfossils,grain size, chemical and mineral analyses indicate turbidity current deposits have been developed in Core SA14-34,At least 4 layers of turbidities can be recognized.These layers,each 18～120 cm thick,are characterized by turbidite sequence with graded bedding,abundant allochthonous calcareous microfossils and high SiO₂/Al₂O₃ ratio,high content of CaCO₃ and high contents of terrigenous detrital minerals.In addition,a preliminary analysis is made on the material source and origin of the turbidity current deposits.The authors suggest that the favorable topography, abundant source materials and earthquakes induced by repeatedly occurring submarine volcanic activities are the main causes for the occurrence of turbidity currents.更多还原