山东中生代橄榄安粗岩系火山岩的地质、地球化学特征及岩石成因  

GEOLOGY,GEOCHEMISTRY AND GENESIS OF THE MESOZOIC SHOSHONITIC VOLCANIC ROCKS IN SHANDONG PROVINCE

作　　者：邱检生[1] 王德滋[1] 周金城[1] 曾家湖[1] 

机构地区：[1]南京大学地球科学系

出　　处：《地球科学（中国地质大学学报）》1996年第5期546-552,共7页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金;地质矿产部壳幔体系组成;物质交换及动力学开放研究实验室研究基金

摘　　要：山东中生代橄榄安粗岩系火山岩主要分布在沂沭断裂带及其两侧的断陷型陆相火山盆地中，为早白垩世火山活动的产物．Ｒｂ－Ｓｒ全岩等时年龄变化于１１１．４～１１９．６Ｍａ．岩石组合主要为粗面玄武岩－橄榄安粗岩－安粗岩－粗面岩．这套岩石在化学上具有富碱富钾、富铝贫钛、高氧化系数及富轻稀土和大离子亲石元素的特点，并具有较高的ＩＳｒ值和明显偏低εＮｄ值．根据对岩石地质、地球化学特征和产出构造环境的详细分析。The Mesozoic shoshonitic volcanic rocks in Shandong occurred mainly in the terrestrial fault basins along the Yishu deep fault zone and its both sides.These volcanic rocks were formed in the Early Cretaceous epoch (Rb-Sr isochron ages varying from 111.4-119.6 Ma)and constitute mainly trachybasalt-shoshonite-latite-trachyte association.Chemically,they are rich in alkali,especially potassium,and higher in Al 2O 3 and lower in TiO 2 as well as high Fe 2O 3/(Fe 2O 3+FeO) ratios.Moreover,they are notably enriched in highly incompatible lithophile elements,such as Rb,Th,Ba,LREE,etc.and have higher I sr values and quite low ε Nd values.The detailed analysis of their geological-geochemical characeeristics and rock-forming tectonic setting suggest that the formation of the Mesozoic shoshonitic volcanic rocks in Shandong should be originated mainly from the partial-melting of the enriched mantle.

关 键 词：橄榄安粗岩系 岩石成因 火山岩 地质学 地球化学 

分 类 号：P588.14[天文地球—岩石学] P581[天文地球—地质学]