论文部分内容阅读
冀东卢龙地区新发现的铬云母石英岩为产自冀东太古宙基底中的巨大透镜体(残块),构造位置接近元古宙长城系地层与太古宙基底的不整合之下,与冀东曹庄地区铬云母石英岩产状类似.对其年代学研究发现,卢龙地区铬云母石英岩中碎屑锆石年龄范围为3200~3800 Ma,表明铬云母石英岩形成的年代应小于3200 Ma,这与迁安曹庄地区出露的曹庄组铬云母石英岩中碎屑锆石相同.说明这种含有始太古代碎屑锆石的铬云母石英岩在冀东地区可能还有更广泛的分布.此前认为两个地区铬云母石英岩的围岩分别属于两个不同的构造单元(迁西群和滦县群),但本文新发现的相近年代数据说明这两个岩群可能位于同一构造背景下的同一层位.卢龙地区铬云母石英岩的年代学研究为理解冀东地区太古宙地质构造提供了更多信息.
The newly discovered chrome micaceous quartzite in Ludong area, eastern Hebei Province, is a huge lens (residual mass) produced in the Archean basement of Jidong. Its structural location is close to the unconformity between the Proterozoic Great Wall System and the Archean basement. The chondrite-mica quartzites in the Jiuzhuang area of eastern Jidong are similar in origin, and the chronological study shows that the detrital zircons in the Chromium mica-quartzite in the Lulong area range from 3200 to 3800 Ma, indicating that the age of chrome mica quartzite formation should be less than 3200 Ma, which is the same as the detrital zircons in the Caozhuang Formation chrome micaceous quartzite in the Caozhuang area of Qian’an, indicating that this chrome micaceous quartzite containing Archean detrital zircon may still have More widely distributed.It was previously thought that the surrounding rocks of chrome micaceous quartzite in the two regions belong to two different tectonic units (Qianxi Group and Luanxian Group respectively), but the similar data newly discovered in this paper indicate that the two groups may be Located in the same tectonic setting of the same horizon.Lu Long area chrome micaceous quartzite chronology study to understand the Jidong area Archean geological structure to provide more information.