摘要
钦杭成矿带东段处于华夏地块与扬子地块的交接部位,其特殊的构造背景造就了其独特的岩浆事件与成矿作用。本文详细总结了燕山期中酸性岩浆时空演化与成矿规律,认为钦杭成矿带东段燕山期岩浆活动是连续的,可分为"两期四阶段":早期早阶段(180~160Ma)主要形成I型花岗岩,早期晚阶段(160~145Ma)形成I型、S型花岗岩,晚期早阶段(145~125Ma)以形成S型花岗岩为主(136Ma之后开始形成A型花岗岩),晚期晚阶段(125~100Ma)主要形成A型花岗岩。以东乡-德兴I型花岗岩带为岩浆活动中心,总体经历了从西往东,从I型→S型→A型的演化过程。按成矿专属性,将I型花岗岩分为两种类型:I_1型花岗岩以形成铜(金)铅锌铁多金属矿床为特色,I_2型花岗岩主要形成钨钼矿;将S型花岗岩分为三类:S_1型花岗岩主要形成钨锡钼矿床,高分异的S_2型花岗岩形成铌钽矿,S_3型花岗岩主要形成铅锌银铀矿床;A型花岗岩则具备I型、S型两种花岗岩的成矿特征。与岩浆作用一致,成矿作用也是连续的,可分为相应的"两期四阶段"。成岩成矿的时空演化过程主要受太平洋板块俯冲过程中动力条件变化的控制,导致不同部位的基底地层发生熔融,发生不同程度的壳幔相互作用。
The eastern segment of the Qinhang metallogenic belt is located at the junction of the Huaxia block and the Yangtze block, and its special tectonic setting has created its unique magmatic event and mineralization. In this paper, the spatial-temporal evolution and metallogenic regularity of felsic rocks in Yanshanian are summarized. It is concluded that the Yanshanian magmatic activities, in the eastern segment of Qinhang metallogenic belt, were continuous and can be divided into ＂two periods divided into four stages＂：The early stage of early period （180~160Ma） mainly formed the I-type granitoids, and the late stage of early period （160~145Ma） formed the I-type and S-type granitoids, and the early stage of late period （145~125Ma） mainly formed S-type granitoids （began to form A-type granitoids after 136Ma）, late stage of late period （125~100Ma） mainly formed A-type granitoids. Dongxiang-Dexing I-type granitoids belt as a magma activities center, the study area of intermediate-acidic magmas had experienced a evolution process from west to east and from the I-type→S-type→A-type. According to the characteristics of mineralization, I-type granitoids is divided into two types：I1-type granitoids are characterized by forming copper （gold）-lead-zinc-iron polymetallic deposits, I2-type granitoids mainly form tungsten-molybdenum deposits; S-type granitoids are divided into three types：the S1-type granitoids mainly form the tungsten-chrome-molybdenum deposit, the highly fractionated S2-type granitoids form niobium-tantalum deposits, and the S3-type granitoids mainly form lead-zinc-silver-uranium deposits. The A-type granitoids have all the mineralization characteristics of I-type and S-type granitoids. Consistent with the magma effect, mineralizations were also continuous, can be divided into the corresponding ＂two periods divided into four stages＂. The temporal and spatial evolution regularity of diagenesis and mineralization was mainly controlled by the change of dynamic conditions during the subduction process of the Pacific plate, which led to the melting of different parts the of basement strata, and had experienced varying degrees of crust-mantle interaction.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第11期3635-3658,共24页
Acta Petrologica Sinica
基金
国家重点研发计划(2016YFC0600206)
中国地调局地调项目(1212011120846
12120113065500
DD20160038)联合资助
关键词
钦杭成矿带东段
燕山期
成岩成矿规律
构造背景
岩浆起源
Eastern segment of Qinhang Metallogenic Belt
Yanshan Period
Diagenesis and mineralization regularity
Tectonicsetting
Magmatic origin
作者简介
吕劲松，男，1987年生，助理研究员，从事矿产地质调查、岩石学、矿床学等研究工作，Email：lv-jingsong@qq．com.;通讯作者：张雪辉，男，1983年生，高级工程师，从事区域矿产地质调查、矿床学等研究工作，E—mail：zhangxuehui35@qq．com.
