dacitic

与dacitic相关的网络例句 [注：此内容来源于网络，仅供参考]

Based on major and trace elements and isotope geochemical data, it is inferred that Sandouding suite is formed by magma melting of Late Archeozoic continent tholeiite source, and its geochemical variation is controlled by hornblende fractional crystallization. Besides fractional crystallization, the geochemical variation of Huanglingmiao suite is related to the mixing between dacitic magma and felsic magma. Dalaoling suite is probably derived from early Precambrian volcanics.

根据岩石化学和同位素组成推断，三斗坪岩套的源岩主要是晚太古代大陆拉斑玄武岩，母岩浆相当于英安质，岩套内的成分变化主要受角闪石分离结晶作用控制；黄陵庙岩套除受分离结晶作用影响外，成分变化主要与英安质母岩浆和某种长英质岩浆的混合有关；大老岭岩套的源岩亦为早前寒武纪火山岩。

Volcanic rocks are of the high-K calc-alkaline series rock association, composed mainly of ryholitic and trachytic dacitic rocks, and the central intrusive body is olivine-andesite-trachytic quartz syenitic porphyrite.

火山岩为以流纹质和粗面英安质为主的高钾钙碱性系列岩石组合，中央侵入体为橄榄安粗岩系列石英正长斑岩，它们的A/CNK值集中在0.9～1.2之间，为铝饱和或铝过饱和类型。

The host rocks mainly are meta andesitic dacitic volcanic rocks.

谱线特征为马鞍型，其底坪年龄为石英的结晶年龄。

This thesis studies the volcanic tectono-petrofacies, petrology, mineralogy, geochemistry, isotopic chronology, stratum and high-precision SHRIMP zircon U-Pb datings of the Mt.Yandangshan volcano-intrusive complex, and concludes that: Yandangshan volcanic rock units belong to high-K calc-alkaline acid rock associations, mainly ryholitic and trachytic dacitic in composition. They have A/CNK values of 0.9-1.2 (i.e., aluminium saturation and supersaturation), enriched LREE and LILEs and depleted HFSE. Their 8Eu values are 0.11-0.32, indicating a evident fractional evolution of plagioclase crystallization. Their ∑REE varied very limitedly,(87~Sr/(86)Sri ratios and eNd values are 0.7086～0.7095 and -10.20～-9.96 for volcanic rocks, and 0.7087~0.7095 and -7.6～6.92 for the central intrusive facies syenite, which means that all the igneous rocks from Mt. Yandangshan are evolutional products of magmas with the same source, and that they derived mainly from crust, but mixed with mantle components.

本文从火山构造岩相学、岩石学、矿物学、地球化学、同位素年代学、地层学等方面出发，同时结合高精度SHRIMP锆石U-Pb定年，对雁荡山火山岩进行了系统的研究，确定雁荡山火山岩为一套以流纹质和粗面英安质为主体的高钾钙碱性酸性岩石组合，A/CNK值集中在0.9～1.2之间，为铝饱和或铝过饱和类型；富轻稀土元素和大阳离子亲石元素、相对亏损高场强元素：负铕异常明显，δEu值为0.11～0.32，表明岩浆经历了以斜长石为主的强烈结晶分异作用：岩石样品的∑REE变化有限，火山岩样品的~(87Sr/~(86)Sr_i为0.7086～0.7095，εNd为-10.20～-9.96，中央侵入体石英正长岩~(87Sr/~(86)Sr_i为0.7087～0.7095，εNd为-7.6～-6.92，表明它们是同源岩浆分异演化的产物，物质来源主要为陆壳，但有地幔物质参与。