-
摘要: 西汉末—北宋黄河三角洲是在很浅的水域发育的。在1855年海岸线内侧数千米处三角洲厚度只有12 m左右。无论是整个三角洲，还是水下三角洲各个组成部分（前三角洲、三角洲前缘）都比现代黄河三角洲相应部分要薄。前三角洲之上在不同地点发育三角洲前缘粉砂或者分流间湾黏土质粉砂。推测这一时期三角洲上多条分流同时活动。三角洲中有孔虫和介形虫属种和数量都与下伏陆架沉积物的有明显差别，且自下而上显示越来越受入海河水影响。与苏北、现代黄河三角洲沉积物中生物丰度的比较可以看出沉积速率的增加，反映这一历史时期黄河入海泥沙增加以及黄土高原侵蚀越来越严重。Abstract: The Yellow River Delta superlobe in 111099 formed on a very shallow sea area. The thickness of the delta close to the coast line in 1855 is only 12 m. The delta front silt or interdistributary bay clayey silt accumulates on the prodelta. In the old delta deposits, the bioturbation structure can be observed, the mollusk shells are common, more foraminiferal tests and marine ostracod valves exist. They are different from those in North Jiangsu delta superlobe (11281855) and Modern Delta superlobe (since 1855). These indicate that the sedimentation rate in the old delta superlobe is lower than the other two younger delta superlobes and indirectly indicate the increasing erosion in the Loess Plateau.
-
Key words:
- Yellow River delta /
- delta superlobe /
- sedimentary sequence /
- sedimentation rate
-
点击查看大图
计量
- 文章访问数: 3007
- HTML全文浏览量: 9
- PDF下载量: 909
- 被引次数: 0
下载:
