CAJ | 학술논문

耀岭河群火山岩中可划分出两类不同性质的酸性火山岩:酸性岩A主要属碱流岩-白碱流岩类,酸性岩B主要属流纹英安岩/英安岩类.总体上看二者主量元素组成差异不大:SiO_2含量为65.00%～79.85%,(Na_2O+K_2O)为5.26%～9.68%.强烈富集Th、Nb、Ta、La、Ce、Nd、Zr、Sm和Hf等微量元素,强烈亏损Ba、K、Sr、P、Ti等元素,稀土元素特征表现为∑REE很高(339.94～1152.85μg/g),具有强烈的铕负异常(δEu=0.18～0.32),与典型的大陆裂谷流纹岩的稀土曲线一致.酸性火山岩B显示K、Rb、Ba、Th和LREE的正异常和Sr、P、Ti和Nb的负异常,Eu具弱负异常(δEu=0.64～0.88),表现出与酸性火山岩A迥然不同的微量元素及稀土元素特征,而与耀岭河群基性火山岩相似,显示其成因可能与之有相同源区.
요령하군화산암중가화분출량류불동성질적산성화산암:산성암A주요속감류암-백감류암류,산성암B주요속류문영안암/영안암류.총체상간이자주량원소조성차이불대:SiO_2함량위65.00%～79.85%,(Na_2O+K_2O)위5.26%～9.68%.강렬부집Th、Nb、Ta、La、Ce、Nd、Zr、Sm화Hf등미량원소,강렬우손Ba、K、Sr、P、Ti등원소,희토원소특정표현위∑REE흔고(339.94～1152.85μg/g),구유강렬적유부이상(δEu=0.18～0.32),여전형적대륙렬곡류문암적희토곡선일치.산성화산암B현시K、Rb、Ba、Th화LREE적정이상화Sr、P、Ti화Nb적부이상,Eu구약부이상(δEu=0.64～0.88),표현출여산성화산암A형연불동적미량원소급희토원소특정,이여요령하군기성화산암상사,현시기성인가능여지유상동원구.
The acid volcanic rocks of the Yaolinghe Group can be divided into two types: A-group and B-group, belonging to pantellerite/comendite and rhyodacite/dacite, respectively. The major elemental characteristics of the two types of rocks are quite similar. Their SiO_2 and (Na_2O+K_2O) contents range from 65.00% to 79.85% and 5.26% to 9.68%, respectively. The A-group acid volcanic rocks are rich in Th, Nb, Ta, La, Ce, Nd, Zr, Sm, Hf and depleted in Ba, K, Sr, P, Ti. They are high in ∑REE(339.94～1152.85μg/g) and show notable Eu negative anomalies (Eu/Eu~*=0.18～0.32) on the REE patterns, which are similar to those of typical rhyolites in the continent rift setting. The B-group acid volcanic rocks have high contents of K, Rb, Ba, Th and LREE, and show negative anomalies of Sr, P, Ti, Nb and slight negative Eu anomalies (Eu/Eu~*=0.64～0.88). The characteristics of rare earth and other trace elements of the B-group rocks are obviously different from those of the A-group rocks, but similar to those of their basic counterparts, suggesting that the B-type volcanic rocks may have a close relationship with the basic volcanic rocks originally.