摘要
中条山大陆裂谷发育于晚太古—早元古代,其构造演化完全受制于两大地壳波系的波浪状运动。本文提供了五个方面的证据:①业已从绛县群—中条群及邻区相应地层中,获得大量的2700～2300Ma的同位素年龄数据;②构造变形、岩浆活动等显示了两大地壳波浪的交替作用;③地层剖面结构显示出典型的大陆裂谷建造特征;④岩石地球化学表明绛县群火山岩为“双峰式”,火山岩稀土曲线与世界其它典型的前寒武大陆裂谷一致;⑤花岗岩可分两期,绛县期末为挤压环境,中条期为张裂环境。
The rift in the Zhongtiao Mountains area was developing from the late archeozoic era to the early proterozoic era.It was a continental rift. The structural evolution of this rift was conducted completely by the wavy movement of the two crustal wave systems-the Circumpacific and the Mediterrannean systems. The proofs in five aspects are provided in this paper:
1. A lot of data about the isotopic age between 2700Ma^2300Ma were obtained from the Jiang Xian group-Zhong Tiao group and other corresponding strata in the neighbouring areas.
2. A series of structrual features, the magmatic intrusions and so on in this area were formed in the two periods. They are useful to determine the alternating activity of the two crnstal wave systems.
3. The strata sectional texture has manifested the constructional features of a typical continental rift.
4. The petrochemistry shows that the volcanic rocks in Jiang Xian group are the 'double-crest' type, and the REE corves were uniform with those of other typical
pre-cambriam continental rifts in other areas over the world.
5. The granites in this area can be divided into two periods.One is the late Jiang Xian period and another belongs to the mild Zhong Tiao period. The petrochemistry REE shows that the former was formed in a squeezing circumstance and the later reflects a strentching condition.
基金
地矿部重点科研项目"华北地块南缘元古宙构造演化及成矿特征"报告的一部分
关键词
大陆裂谷
地壳运动
中条山
太古代
Zhongtiaoshan, continental rift, crnstal wavy movement, petrochemistry,granite
