朝鲜～19亿年侵入岩的岩石类型与构造背景初探  

A preliminary study on the rock series and tectonic environment of the ～1.9Ga plutonic rocks in DPR Korea

作　　者：彭澎[1,2] 王冲[1,2] 杨正赫 金正男[3] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [2]中国科学院大学地球科学学院,北京100049 [3]朝鲜国家科学院地质研究所,平壤3812100

出　　处：《岩石学报》2016年第10期2993-3018,共26页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(41210003、41322018);中组部青年拔尖人才项目联合资助

摘　　要：朝鲜半岛北部广泛发育～19亿年侵入岩,这些岩浆岩可以分为三个系列,分别为似斑状花岗岩系列（多为I型,以妙香山岩体为代表,年龄1900～1840Ma）、S型花岗岩系列（以嘉山岩体为代表,本文获得1862±5Ma锆石U-Pb年龄）和正长岩系列（以龙浦岩体为代表,本文获得1857±2Ma锆石U-Pb年龄）。似斑状花岗岩系列（I型花岗岩）大致对应朝鲜地质学家定义的Myohyangsan（妙香山）杂岩,以发育钾长石巨斑为特征,与麻粒岩相变质的火山岩-沉积岩系关系密切;S型花岗岩系列大致对应Ryonhwasan（莲花山）杂岩,以发育石榴石和堇青石等矿物为特征,与麻粒岩相变质的副变质岩共生：这说明前者可能与变质火山岩系相关,而后者可能和副变质岩相关。正长岩系列,朝鲜地质学家称为Sakju（朔州）杂岩,分布较为局限,仅见于朔州以及博川-定州之间,也见于邻区辽东,多为岩株。这三个系列岩浆岩稍早或者同期于角闪岩相-麻粒岩相变质（本文获得甑山＂群＂变质锆石U-Pb年龄1844±2Ma）。邻区辽东-吉南及胶东地区也发育这三个系列岩浆岩,但这两个地区～21亿年岩浆作用更为广泛。朝鲜半岛南部发育大量同期岩浆岩,但岩石类型以似斑状花岗岩为主,并发育紫苏花岗岩和斜长岩。我们推测,朝鲜半岛南北两侧基底属性存在差异,可能对应不同的古陆（华北与华南古陆）。综合分析表明,朝鲜～19亿年前广泛发育I型和S型花岗岩,并有幔源岩浆作用,同时发育正长岩类,并且这些岩浆活动与区域高级变质作用时代接近。考虑到本区存在太古宙基底,我们推测本区在古元古代可能处于类似现今活动大陆边缘弧背景。There are widespread ～ 1.9 Ga plutonic rocks in DPR Korea,which can be subdivided into three series,a porphyritic granite series（ I-type granites,e.g.,the Myohyangsan pluton,1900 ～ 1840 Ma）,S-type granite series（ e.g.,the Gasan pluton,a1862 ± 5 Ma zircon U-Pb age is obtained） and the syenite series（ the Ryongpo pluton as an example,a 1857 ± 2 Ma zircon U-Pb age is obtained）.The I-type granite series is called the Myohyangsan Complex by local geologists,and is characterized by megacrysts of Kfeldspar and is closely occurred with the granulite facies meta-volcanics/sediments; whereas the S-type granite series is called the Ryonhwasan Complex,and is characterized by containing garnet and cordierite and is distributed in the high-grade paragneisses.This indicates that the S-type granites could be originated from paragneisses; while the porphyritic granite series（ I-type granite） could be associated with the volcanic-containing supracrustal rocks.The syenite series is called as the Sakju Complex by local geologists,and is limitedly distributed in Sakju and Tokchong-Chongju and the neighbouring Liaodong Peninsula,and appears as stocks.These plutons are slightly older or basically coeval with the metamorphism timing of the regional amphibolite-granulite facies metamorphism（ a 1844 ±2 Ma zircon U-Pb age is obtained from paragneiss of the Jungsan ‘Group＇）.The syenite series could be originated from high-pressure melting of crustal materials.There are also similar series of plutons in the neighboring Liaodong-Jinan and Jiaodong areas,where the～ 2.1 Ga igneous rocks are more prominent.There are also widespread ～ 1.9 Ga plutons in southern Korean Peninsula; however,these are dominantly porphyritic granites with a few charnockite and anorthosite.It may indicate different basements for the north and south part of the peninsula,i.e.,they may belong to different paleo-continents（ North and South China blocks）.The widespread ～ 1.9 Ga I-type and S-type granites with locally syenites and som

关 键 词：华北古陆 朝鲜半岛 古元古代 S型花岗岩 似斑状花岗岩(I型花岗岩) 正长岩 

分 类 号：P534.1[天文地球—古生物学与地层学] P588.12[天文地球—地质学]