摘要
浙江漓渚地区位于钦杭成矿带北东段,发育矽卡岩型铁或铁多金属矿床或矿(化)点,成矿作用与沿北东走向褶皱-断裂带发育的晚侏罗世末栅溪—广山侵入岩密切相关;栅溪岩体岩石类型主要为中细粒石英(花岗)闪长岩,广山岩体岩石类型主要为中粒及细粒花岗岩;前者为含角闪石钙碱性(低钾-高钙)花岗岩类(ACG),具有低硅,贫碱,富钙、镁和铁的特征,相对富集K、Rb、Ba、Th、U、Zr、Hf等元素,弱亏损Sr、Ti等元素,具弱负铕异常及向右弱倾的稀土配分曲线特征,地球化学类似I型花岗岩特征;后者为富碱钙碱性(高钾-低钙)花岗岩类(KCG),具有高硅、富碱、低钙和镁铁的特征,富集K、Rb、Th、U、Nb、Ta、Zr、Hf等元素,强亏损Ba、Sr、Ti等元素,具强负铕异常及"V"型稀土配分曲线特征,地球化学类似A型花岗岩特征。成岩构造环境具有从俯冲碰撞作用向后碰撞或后造山作用转换的特征,转换时间与华南地区构造环境转换时间吻合,为华南构造-岩浆演化提供新的约束;且这两类侵入岩在浙江分布广,均具有较好的成矿潜力及找矿前景。
Located in the northeastern part of the Qinhang metallogenic belt, Lizhu area in Zhejiang has developed a series of skarn type iron polymetallic deposits or ore spots, and mineralization is closely related to the late Jurassic intrusive rocks in the NE-trending fold-fault zone. Researches on the geological and geochemical characteristics of intrusive rocks show that the main rock types are middle-fine grained granodiorite and coarse- grained or fine-grained granite. The former type comprises amphibole-bearing calc-alkaline （ low potassium- high calcium） granitoids （ACG） characterized by low SiO2, K20 ＋Na20 and K2O/Na2O, rich CaO, MgO and FeOT, relative enrichment of K, Rb, Ba, Th, U, Zr, Hf, slight depletion of Sr, Ti, negative Eu anomalies along REE distribution curve with weakly right-oblique nature, similar geochemically to the I-type granite. The latter type consists of alkali-rich calc-alkaline （high potassium-low calcium） granitoids （KCG）, characterized by high SiO2,K20＋Na20 and K20/Na20, low CaO, MgO and FeO^T, enrichment of K, Rb, Th, U, Nb, Ta, Zr, Hf, strong depletion of Ba, St, Ti, and obvious negative Eu and ＂V＂-type REE patterns, thus similar geochemically to the A-type granites. The petrogenetic tectonic environment was converted from the subduction collision to post-collision or post-orogeny, consistent with the conversion of the tectonic environment in South China, thus providing a new constraint for the tectonic-magmatic evolution in South China. Furthermore, both the two types of granites widespread in Zhejiang have good prospecting potential.
出处
《中国地质》
CAS
CSCD
北大核心
2013年第2期403-413,共11页
Geology in China
基金
中国地质调查局地质大调查项目(1212010011730)资助
关键词
地球化学
构造意义
栅溪—广山岩体
漓渚地区
浙江
geochemistry
tectonic significance
Shanxi- Guangshan intrusions
Lizhu area
Zhejiang
作者简介
张建芳，男，1985年生，硕士，助理工程师，从事矿产资源调查与研究工作；E—mail：zhjianfang@126．com。
