| 摘要: |
| 70年代末，水文地质部门在华北平原上打了大量第四系钻孔，1993年对其中近百个钻孔的沉积相和测年资料重新进行分析，发现在该区全新统之下、上更新统上部普遍发育了一层细砂层，埋深一般为对20 - 40m。厚度约为5 - 20m，平面分布连续而稳定。90年代在黄渤海进行过数千公里的浅地层剖面测量，在海底以下十几米至40m左右的深度也发现该细砂层，厚约为15 - 30m。剖面仪记录下该砂层发育有大倾角斜层理，其倾角达10 - 20°，将其定为风成沉积。本次冰期盛时，无论是华北平原还是黄渤海陆架，均未发育以粉砂为主的黄河沉积。因此，笔者认为本次冰期盛时的21 - 13kaB．P，黄河解体消亡，因而未能东流入海。这一结论，恰与当时黄河流域气候干旱、降水量小的古地理环境特点相吻合。 |
| 关键词: 末次冰期 黄河 解体 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，48970272号 |
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| A PRELIMINARY STUDY ON DISINTEGRATION EVENT OF THE HUANGHE RIVER DURING THE MAXIMUM OF THE LAST GLACIAL PERIOD |
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Xia Dongxing, Liu Zhenxia, Wu Sangyun, Cui jinrui
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First Institute qt Oceanography, SOA, Qingdao 266003
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| Abstract: |
| Analysis of the sedimentary facies factors such as grain size, microfossils, etc. of sediment samples and isotopic datings of the materials from up to 100
Quaternary cores drilled in the North China Plain in late 1970 s revealed that there was a widespread fine sand layer under the Holocene deposition series in this region. This fine sand layer, about 5 – 20 m in thickness and buried by the 20 – 40 m thick in Holocene deposition, was continuously and constantly distributed in the plain. In the past 10 - odd years, shallow profiling surveys for thousands of kilometres were conducted in the shelves of the Bohai Sea and the Yellow Sea. By correlation with the sea-bottom drillings, interpretation of the profiling records revealed that there was also a widespread fine sand layer of the same age as that in the North China Plain at the depth interval from 10 - odd m to 40 m beneath the sea bed. This fine sand layer showed high - angle (10 - 20 °) inclined beddings in the profiling graphs. Thus it was defined as aeolian deposition. Dining the maximum of the last glacial period, the Huanghe River sediment consisting mainly of silt grains was absent both in the North China Plain and in the shelves of the Bohai Sea and the Yellow Sea. Based on these facts, the author concluded that during the stage from 21 ka B. P. to 13 ka B. P., the Huanghe River was disintegrated and extinguished. This conclusion is confirmed by the climatic environmental conditions in the drainage area of the Huanghe River in that stage, the precipitation in the upper-middle reach areas of the modern Huanghe River during the maximum of the last glacial period was only 200 mm, thus it was very difficult for the Huanghe River to catch enough water to flow across the North China Plain and the vast shelf areas which were exposed from the sea and finally reach the coastline which had retreated to the margin of the continental shelf of the East China Sea. |
| Key words: Last glacial period, Huanghe River, Disintegration |
