投稿时间：2019-08-18
修订日期：2019-09-10
网络发布日期：2019-11-04
中文摘要:东秦岭地区和阿尔泰造山带均产出大量稀有金属伟晶岩，是中国重要的稀有金属产地。前者工作程度低，远景尚不明朗；后者规模巨大。开展成矿条件对比研究十分必要。东秦岭地区产出铍矿、锂矿和复杂稀有金属矿，以锂矿化为主，伟晶岩类型复杂，包括绿柱石-铌铁矿型、复杂型锂辉石亚型、复杂型锂云母亚型和钠长石-锂辉石型。阿尔泰稀有金属伟晶岩发育多种稀有金属矿化组合，伟晶岩类型为绿柱石-铌铁矿型、复杂型锂辉石亚型和钠长石-锂辉石型。东秦岭稀有金属伟晶岩的内部结构分带型式包括对称分带结构、均一结构和分层结构，阿尔泰稀有金属伟晶岩以对称分带结构为主，也见均一结构。东秦岭与阿尔泰稀有金属矿石矿物相近，东秦岭产出更多含锂磷酸盐矿物。东秦岭稀有金属伟晶岩分异演化程度相对集中且高，阿尔泰稀有金属伟晶岩分异演化程度跨度大。东秦岭和阿尔泰锂矿的锂矿化主要发生于岩浆就位前，复杂稀有金属矿稀有金属富集作用发生在岩浆就位前和就位后，但阿尔泰复杂稀有金属矿经历了更为复杂和极度的分异演化过程。东秦岭稀有金属伟晶岩可能与同期花岗岩为同一熔融事件的产物，与早期花岗岩来自同一物质来源。阿尔泰稀有金属伟晶岩与花岗岩关系复杂，但大量早期花岗岩的形成提高了地壳成熟度，有利于形成晚期稀有金属伟晶岩。东秦岭稀有金属伟晶岩产出于北秦岭单元中，形成于晚造山和造山后阶段，集中于造山后阶段，稀有金属矿化呈多期断续叠加特征。阿尔泰稀有金属伟晶岩主要产出于琼库尔-阿巴宫地体和中阿尔泰山地体内，集中于造山后和非造山阶段。伟晶岩岩浆活动受控于物质来源和造山作用。储存稀有金属的岩石在造山作用中熔融，发生多期的大规模花岗质岩浆活动，稀有金属通过长期复杂的分异演化过程在残余熔体中不断富集。这种富挥发分和稀有金属的过铝质硅酸盐岩浆随后上升就位，可经后续冷却结晶和不混溶作用进一步富集稀有金属，从而形成稀有金属伟晶岩。东秦岭具有形成含稀有金属高度分异演化岩浆的有利条件，该区具有寻找铍矿和复杂稀有金属矿的潜力。
Abstract:The East Qinling and Chinese Altay host lots of rare-element (REL) pegmatite dykes and both are important producing area for rare element. The former has a low level of geological work with uncertain REL prospects, while the latter has a huge REL reserve. Therefore, it is essential to make comparative studies on ore-forming conditions. The East Qinling is dominated by lithium deposits, although there are deposits of beryllium, lithium and multi REL. The pegmatite types are beryl-columbite type, spodumene subtype and lepidolite subtype in complex type and albite-spodumene type. The REL pegmatites in the Chinese Altay show multi REL mineralization types and belong to beryl-columbite type, spodumene subtype in complex type and albite-spodumene type, respectively. The internal structures of the REL pegmatites in the East Qinling are zoned, homogeneous and layered, while those in the Chinese Altay are mainly zoned and occasionally homogeneous. The REL minerals from the East Qinling are similar to those of the Chinese Altay and relatively enriched in lithium-bearing phosphates. The REL pegmatites in the East Qinling are mostly highly evolved on accounts of major lithium deposits, while the degree of evolution for the REL pegmatites in the Chinese Altay is in a wide range due to various REL deposits. In the East Qinling and Chinese Altay, the mineralization processes for the lithium deposits mainly occurred before emplacement and those of the complex REL deposits happen before and after emplacement, but the complex REL deposits in the Chinese Altay experience more complex and extremely high fractional and evolution processes. In the East Qinling, the REL pegmatites and coeval granites might be both of products of the same melting event, while the REL pegmatites and the earlier granites might have the same origin. The relationships of granites and REL pegmatites in the Chinese Altay are more complex and the earlier granites might result in a fertile crust which is beneficial to formation of the REL pegmatites. The REL pegmatites in the East Qinling occurred in the North Qinling unit and formed in late-orogenic and post-orogenic stages, concentrating in post-orogenic stage. The REL pegmatites in the Chinese Altay are mainly limited in the Qiongkuer-Abagong and Middle Altayshan terranes and concentrated in the post-orogenic and anorogenic stages. The pegmatite magma activities are controlled by origin and orogeny. The rocks hosting REL are partial melted during orogeny. Accompanied with forming large-scale granitic intrusions, REL are continuously enriched during these long and complex fractionation and evolution processes. Finally, the peraluminous silicate magma enriched in fluxes and REL is produced and emplaced to form REL pegmatites on the basis of subsequent crystallization and liquid immiscibility. The East Qinling are favorable to form highly evolved silicate magma containing REL and are also potential area for beryllium and complex REL pegmatites.
keywords:geology granitic pegmatite internal structural patterns rare element mineralization East Qinling Altay
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基金项目:本文得到国家自然科学基金项目（编号：41602095）、岩石圈演化国家重点实验室开放课题（编号：201304）和国家"十二五"科技支撑计划新疆305项目（编号：2011BAB06B03-04）联合资助
引用文本：
秦克章,周起凤,唐冬梅,王春龙.2019.东秦岭稀有金属伟晶岩的类型、内部结构、矿化及远景——兼与阿尔泰地区对比[J].矿床地质,38(5):970~982QIN KeZhang,ZHOU QiFeng,TANG DongMei,WANG ChunLong.2019.Types, internal structural patterns, mineralization and prospects of rareelement pegmatites in East Qinling Mountain in comparison with features of Chinese Altay[J].Mineral Deposits38(5):970~982
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