论文部分内容阅读
末次间冰期高海面时期（７５～１２８ｋａＢ．Ｐ．），在南黄海ＱＣ２孔发现了介形类化石群中“环北极种”为其优势种，组合中数量最多的是Ｓａｒｓｉｃｙｔｈｅｒｉｄｅａｂｒａｄｉ，其现代分布范围在我国浅海区十分狭窄，集中在北黄海冷水团控制区，冷水种在整个间冰期化石组合中占７９％以上；有孔虫组合在７０％以上的沉积层段中其优势种和主要成分以凉水种和喜凉种为主，如Ｂｕｃｃｅｌａｆｒｉｇｉｄａ，Ｐｒｏｔｅｌｐｈｉｄｉｕｍｔｕｂｅｒｃｕｌａｔｕｍ，Ｎｏｎｉｏｎｅｌａｓｔｅｌａ，Ｅｌｐｈｉｄｉｕｍｍａｇｅｌａｎｉｃｕｍ等，它们是北黄海现代有孔虫组合中的主要成分，Ｂｕｃｃｅｌａｆｒｉｇｉｄａ含量超过１０％的分布范围亦仅限于北黄海地区。现代北黄海冷水团中心底层水夏季多年平均温度仅５．８１℃，据此可推测末次间冰期南黄海存在着稳定的冷水团，其中心位于３４°１８′Ｎ，１２２°１０′Ｅ，较现代冷水团偏西南约１５０ｋｍ。在这个古冷水团中心，由于黄海环流的轴辐聚效应，形成了厚达１７ｍ的连续的浅海相“涡旋泥质沉积层”，与现代冷水团中心的“涡旋泥质沉积”相似。
In the last interglacial high sea surface period (75 ~ 128kaB.P.), “Ring-shaped Arctic species” was the dominant species in the ostracod group QC2 in southern Yellow Sea. The most abundant species in the assemblage is Sarsicytherideabradi. Its modern distribution range In China’s shallow sea area is very narrow, concentrated in the northern Yellow Sea cold water mass control area, cold water species in the entire interglacial fossil assemblage accounted for more than 79%; foraminiferal assemblage in more than 70% of the sedimentary section in the dominant species and the main component Such as Buccelafrigida, Protelphidium tuberculatum, Nonionelastela, Elphidiummagelanicum, etc., which are the main components in the modern foraminifera assemblage in North Yellow Sea. The distribution range of more than 10% of Buccelafrigida is also limited to the North Yellow Sea. The average temperature of the bottom water in the modern North Yellow Sea cold water mass center in summer is only 5.81 ℃. Therefore, it can be inferred that there is a stable cold water mass in the southern Yellow Sea in the last interglacial period with its center located at 34 ° 18’N and 122 ° 10’E Modern cold water group about 150km southwest. In the center of this old cold water mass, a continuous shallow marine “vortex muddy deposit” of up to 17 m in thickness was formed due to the axis-gathering effect of the Yellow Sea circulation, similar to the “swirling muddy deposits” in the center of a modern cold water mass.