CAJ | 학술논문

松辽盆地东南缘的三台地区营城组火山岩分布广泛,其中一部分为珍珠岩.通过岩石薄片鉴定,挑选了三台地区北山上的6块珍珠岩样品,进行了主量元素、微量及稀土元素分析测试.珍珠岩的主量元素组成表明,它们与流纹岩成分相当,具有高SiO_2、较高(NaO_2+K_2O)、低TiO_2和低CaO含量,属于铝饱和-弱过饱和的钙碱性系列.稀土元素配分模式以轻稀土富集、Eu负异常强烈为特征.在不相容元素蛛网图上,珍珠岩相对于洋脊花岗岩总体上富集大离子亲石元素和轻稀土元素.而明显亏损高场强元素Sr、Nb、Y.在Nb-Y和Rb-(Y+Nb)判别图上,它们分别落入板内和火山弧区.这些结果显示,所研究的珍珠岩应为类似弧后盆地的引张环境.
송료분지동남연적삼태지구영성조화산암분포엄범,기중일부분위진주암.통과암석박편감정,도선료삼태지구북산상적6괴진주암양품,진행료주량원소、미량급희토원소분석측시.진주암적주량원소조성표명,타문여류문암성분상당,구유고SiO_2、교고(NaO_2+K_2O)、저TiO_2화저CaO함량,속우려포화-약과포화적개감성계렬.희토원소배분모식이경희토부집、Eu부이상강렬위특정.재불상용원소주망도상,진주암상대우양척화강암총체상부집대리자친석원소화경희토원소.이명현우손고장강원소Sr、Nb、Y.재Nb-Y화Rb-(Y+Nb)판별도상,타문분별락입판내화화산호구.저사결과현시,소연구적진주암응위유사호후분지적인장배경.
The volcanic rock of the Yingcheng Formatiom distributes widely in Santai region, Songlian basin. The characteristics of lithofacies shows that perlite develops in the Yingcheng Formation. The major elements, trace elements and REE of 6 samples from Beishan are analysed, which they are selected by examination of thin sections. Its major element compositions indicate that the perlite is similar to rhyolite. Perlite is characterized by high SiO_2, high ( Na_2O + K_2O), low TiO_2 and low CaO contents, symbolizing that it belongs to the aluminous saturated-weak supersaturated calc alkaline series. All the samples are plotted in the sub-aluminous field in the ACNK-ANK diagram. The chondrite-normalized REE patterns for these rocks display LREE enrichment and strongly negative Eu anomaly. Compared to ocean ridge granite, the rocks are generally enriched in LILE and LREE, but depleted in HFSE including Sr, Nb, Y as indicated in the spider diagram. In addition, the samples are plotted in the fields defined by volcanic arc and intraplate granite in the Nb-Y and Rb-(Y+Nb) discrimination diagrams. All these characteristics suggest that the perlite formed in an extension which is similar to back-arc basin.