2007-2010年野外采样及室内处理分析数据集

此数据集共包括铜厂闪长岩、钠长岩的主量元素、微量元素、稀土元素和锆石Shrimp U-Pb同位素年龄与Lu、Hf同位素及微量元素数据：

其中，用于主量、微量及稀土元素的闪长岩分别采自铜厂矿区后沟、罗家沟和新铜厂等地各8个样品，用于挑选锆石的闪长岩取自陕西省南部略阳县铜厂矿区后沟-罗家沟之间3个样品组合样。研究结果表明铜厂闪长岩属于钙碱性-低钾岩系列岩石，以富大离子亲石元素和贫高场强元素为特征，其稀土配分模式为具Eu负异常和Ce异常不明显的轻稀土富集型，与碧口群海相火山岩具有一定相似性和继承性。闪长岩主要来源于壳源或曾受到地壳物质的强烈混染，并没有经历过显著的结晶分异演化，且与铜成矿有密切的关系，为该区主要成矿物质来源之一。岩体形成的大地构造背景属于碰撞隆起-岛弧火山，成矿作用晚于岩体侵入。铜厂闪长岩的锆石SHRIMP U-Pb 同位素年龄为842±6.5Ma，早于秦岭造山带的主造山期。该区晋宁期俯冲-挤压造山作用，形成了碧口岩群岛弧火山岩系，铜厂闪长岩可能属于地层-碧口群细碧角斑岩末期火山侵入杂岩，由碧口群火山岩的局部熔融作用形成，其轻稀土的相对富集可能与岩体继承源岩的稀土特征有关。

其中，用于主量、微量及稀土元素的钠长岩分别采自铜厂矿区龚家沟-黄家沟-后沟等地各8个样品，用于挑选锆石的闪长岩其中3个样品组合样。研究结果表明该类岩石以富钠质为特征，其主量元素介于晚元古代郭家沟组细碧岩和矿区闪长岩之间，微量元素及稀土元素组成变化范围相对较宽，总体上与矿区闪长岩类似，以富大离子亲石元素和贫高场强元素为特征，其稀土元素总量相对较低，配分模式属于轻稀土富集中等右倾曲线，以Eu弱负异常为主要特征。该类岩石各类岩石地球化学特征参数相似于典型交代成因钠长岩，明显有别于典型热水沉积成因钠长岩。结合其地质产出特征，铜厂钠长岩应为闪长岩受到钠质交代作用所形成，锆石SHRIMP U-Pb年代学研究结果显示其原岩形成于844.4±8.2Ma，属于闪长岩较早阶段侵入的产物（842.8±6.5Ma），其全岩Rb-Sr年龄（348Ma）与秦岭地区海西早期大规模钠质活动较吻合，可能反映的是原岩遭受钠质交代作用的时限。

This dataset includes major, trace, and rare earth element (REE) data, as well as zircon SHRIMP U-Pb isotopic ages, Lu and Hf isotopic, and trace element data for diorites and albitites from the Tongchang deposit.

For diorites used for major, trace and REE analyses, 8 samples were collected respectively from Hougou, Luojiaogou, and Xintongchang in the Tongchang mining area; the diorite samples for zircon separation were composite samples of 3 specimens collected between Hougou and Luojiaogou in the Tongchang mining area, Lueyang County, southern Shaanxi Province. Studies show that the Tongchang diorites belong to the calc-alkaline-low-K rock series, characterized by enrichment in large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs). Their REE partition patterns are light REE-enriched types with Eu negative anomalies and indistinct Ce anomalies, showing certain similarities and inheritance with the Bikou Group marine volcanic rocks. The diorites are mainly derived from crustal sources or strongly contaminated by crustal materials, without experiencing significant fractional crystallization evolution. They are closely related to copper mineralization and are one of the main ore-forming material sources in this area. The tectonic setting for the emplacement of these diorites is collisional uplift-island arc volcanism, and mineralization occurred later than the intrusion of the rock mass. The zircon SHRIMP U-Pb isotopic age of the Tongchang diorites is 842±6.5 Ma, which is earlier than the main orogenic phase of the Qinling orogenic belt. The subduction-compressional orogeny during the Jinningian period in this area formed the Bikou Group island arc volcanic rock series. The Tongchang diorites may belong to the late volcanic intrusive complex of the Bikou Group spilite-keratophyre strata, formed by partial melting of Bikou Group volcanic rocks. Their relative enrichment in light REEs may be related to the inheritance of REE characteristics from their source rocks.

For albitites used for major, trace and REE analyses, 8 samples were collected respectively from Gongjiagou, Huangjiagou, Hougou and other locations in the Tongchang mining area; the albitite samples for zircon separation were composite samples of 3 specimens. Studies show that these albitites are characterized by sodium enrichment. Their major element compositions fall between the Neoproterozoic Guojiaogou Formation spilites and the diorites from the mining area. Their trace and REE compositions have a relatively wide variation range, but are generally similar to the mining area diorites, also characterized by enrichment in LILEs and depletion in HFSEs. Their total REE contents are relatively low, with REE partition patterns belonging to light REE-enriched moderately right-dipping curves, mainly featuring weak Eu negative anomalies. The geochemical parameters of these albitites are similar to typical metasomatic albitites, and distinctly different from typical hydrothermal sedimentary albitites. Combined with their geological occurrence characteristics, the Tongchang albitites should have formed via sodium metasomatism of diorites. Zircon SHRIMP U-Pb geochronological studies show that their protoliths formed at 844.4±8.2 Ma, which corresponds to the diorites emplaced in an earlier stage (842.8±6.5 Ma). Their whole-rock Rb-Sr age (348 Ma) is consistent with the large-scale sodium metasomatic activity during the Early Hercynian in the Qinling area, which may reflect the timing when the protoliths underwent sodium metasomatism.

搜集汇总

背景与挑战

背景概述

该数据集收集了2007年至2010年在陕西省略阳县铜厂矿区采集的闪长岩和钠长岩样品的地球化学数据，包括主量元素、微量元素、稀土元素以及锆石SHRIMP U-Pb同位素年龄、Lu-Hf同位素和微量元素分析。数据集揭示了这些岩石的地球化学特征、成因（如闪长岩的壳源起源和钠长岩的钠质交代作用）、形成年龄（约842-844 Ma，属于晋宁期）及其与铜成矿的密切关系，为研究秦岭造山带的构造演化和成矿过程提供了重要数据支撑。