富锦隆起泥盆系与变质基底角度不整合关系的发现及构造意义  

Discovery and tectonic significance of unconformity in Devonian with its underlying metamorphic basement in Fujin uplift

作　　者：付秋林[1] 张兴洲[1] 曾振[1] 蒲建彬[1] 

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《世界地质》2016年第2期458-469,共12页World Geology

基　　金：中国地质调查局项目(1212011120973;1212011220754)联合资助

摘　　要：为了解富锦隆起的构造演化,研究了佳木斯地块东北部富锦隆起地区一套含砾粗砂岩-石英砂与花岗片麻岩不整合面。LA-ICP-MS锆石U-Pb年代学结果表明,花岗片麻岩的加权平均年龄为495±5 Ma,石英砂岩中的碎屑锆石年龄均〉480 Ma,其中以480~520 Ma的年龄组为主体,并含有少量年龄〉800 Ma的锆石。角度不整合及年代学证据充分表明,富锦隆起是佳木斯地块的组成部分。鉴于佳木斯地块缺失奥陶纪—志留纪沉积,推测这套含砾粗砂岩-石英砂岩的形成时代为泥盆纪。结合区域资料,认为佳木斯地块的变质结晶基底形成后,经历了长期的隆升剥蚀,到早泥盆世,其东部整体转为被动大陆边缘。In order to understand the tectonic evolution of Fujin uplift,the authors studied the unconformity of conglomeratic sandstone-quartz sandstone with its underlying granitic gneiss in Fujin uplift of northeastern Jiamusi Massif. Based on the LA-ICP-MS zircon dating,granitic gneiss weighted mean age is 495 ± 5 Ma. The U-Pb ages for zircons from quartz sandstone are all more than 480 Ma,of which are mainly concentrated in the age of 480 ~520 Ma,and just a small amount of ages are more than 800 Ma. The evidence of unconformity and geochronology indicates that the Fujin uplift is a part of Jiamusi Massif. Due to the Jiamusi Massif lacking of the Ordovician and Silurian sediments,it suggested that the forming time of the conglomeratic sandstones and quartz sandstone is Devonian. Combined with the regional research data,it is considered that after the formation of metamorphic crystalline basement,the Jiamusi Massif was undergone long-time uplift and erosion until Early Devonian,then the eastern part of the Massif was whole turning into passive continental margin.

关 键 词：富锦隆起 佳木斯地块 泥盆纪 变质结晶基底 角度不整合 

分 类 号：P542[天文地球—构造地质学]