东北地区中泥盆世岩相古地理研究

利用野外实测剖面资料和区域地质资料,在地层划分、对比和构造格局研究基础上,从点-线-面的沉积相分析入手,将中泥盆世分为艾费尔期、吉维特期两个编图单元,进行岩相古地理编图,恢复了东北地区中泥盆世的岩相古地理面貌。研究表明,中泥盆世东北地区艾费尔期沉积环境多为浅海陆棚相碎屑岩沉积及碳酸盐岩台地相沉积;佳木斯-松嫩微板块部分地区及额尔古纳-兴安微板块为古陆;内蒙古东乌珠穆沁旗哈诺敖包一带为滨海沼泽相沉积。吉维特期出现大规模海退,主要表现为:研究区南部沿西拉木伦缝合带一线未见沉积;延寿县马鞍山福兴屯一带发育福兴屯组湖相沉积;兴安海区西南段东乌珠穆沁旗一带的塔尔巴格特组表现为进积-加积型层序,由艾费尔期泥鳅河组浅海沉积过渡为滨海沉积为主。

Lithofacies Palaeogeography of Middle Denovian in Northeast China

On the basis of stratigraphic division, correlation, and the study of structural pattern, the field data of the measurement strata sections and the existing regional geological data were used to do the sedimentary facies analysis from the sections to the whole study area. The lithofacies paleogeographic maps of Eifelian and Givetian of Middle Devonian were mapped in the Northeast China. The study shows that sedimentary environment includes neritic shelf elastic rock sedimentary facies and carbonate platform facies during the Middle Denovian in Northeast China. The old lands are the microplate of Eergu＇na -Xing＇an and some parts of Jiamusi-Songnen; In Hanoch＇obo of East Ujimqin Banner there are the littoral facies. Large-scale regression appear during the Givetian in the South of the study area; Along the line of Xar Moron suture there is no deposit; Lacustrine sediments are discovered in Fuxing village Yan- shou county;Sedimentary facies of Taerbagete formation in East Ujimqin Banner of Inner Mongolia is the Prograde- aggradation type sequence. The sedimentary facies of Eifelian transit from shallow sea deposit to coastal deposits.