摘要
辽宁本溪地区条带状铁矿(BIF)与其玄武质火山围岩之间的时空关联非常密切.对于玄武质火山围岩高场强元素(HFSE)的研究表明:wNb/wTa比值(7.00-19.93)表现出明显的分异,而wZr/wHf比值(33.46-38.28)则变化不大;从弓长岭到南芬、歪头山样品的wNb/wTa比值变化具有明显的循序性.这种高场强元素的迁移和分异特征反映出俯冲作用与盆地演化之间的关联.研究区玄武质火山围岩(wNb/wYb)N比值大于1(1.21-18.45,平均2.72),这进一步表明,其形成的构造背景为陆内弧后盆地提供了有利于BIF形成的条件.
BIFs have spatial and temporal association with their basaltic volcanic wall rocks in Benxi area of Liaoning Province.Through an analysis on the HFSE(high field-strength element)characteristics of basaltic volcanic wall rocks around BIFs,it was found that their wNb/wTaratios(7.00 - 19.93) were remarkably fractionated,but the fractionation of wZr/wHfratios(33.46 -38.28) was not so obvious.In addition,the fractionation of wNb/wTaratios had regional tendency from Gongchangling to Nanfen and Waitoushan.These migration and fractionation characteristics of HFSE showed a connection between basin evolution and subduction process.Their(wNb/wYb)N ratios(1.21 - 18.45,average 2.72) were greater than 1,further suggesting that the tectonic setting for BIFs in the studied area was an intra-continental back arc basin.
出处
《东北大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2016年第8期1172-1176,共5页
Journal of Northeastern University(Natural Science)
基金
国家重点基础研究发展计划项目(2012CB416800)
国家自然科学基金资助项目(41372098)
中央高校基本科研业务费专项资金资助项目(N120401003)
关键词
本溪地区
BIF
玄武质火山围岩
高场强元素
陆内弧后盆地
Benxi area
BIF
basaltic volcanic wall rock
HFSE(high field-strength element)
intra-continental back arc basin