摘要
应用高分辨地球物理测量手段在南黄海中部深水区测量，发现了大面积以前积与前人所述反射结构为特征的埋藏三角洲地层。经过岩芯沉积成份分析、有孔虫组合、１４Ｃ年龄测定，证明是晚更新世晚期海退时期的古黄河三角洲沉积，并能与相邻的地层时代和沉积环境对应。结合华北平原与陆架区埋藏古河道的研究证明，晚更新世晚期低海面时期已经形成了黄河，并且流进了渤、黄海陆架海区。
During 1983~1993, sub bottom stratigraphic sequences were measured by high resolusion geophysical instrument and sedimentary body characterized by large scale, low angle and progradational reflection configuration with the feature of delta structure was found in the central deep water area of the south Yellow sea (123°40′~124°06′E, 34°02′~35°N). The extent of the sedimentary body is 50 km^60 km in the surveying line direction with the thickness of 15 m~ 20m. In the area near the No.56 station, two reflection surfaces (T 1,T 2) and three strata (A,B,C) are distingushed below seabottom within 30 m, according to the feature of acoustical reflection configuration. The stratum above T 1 represents Holocene series marine sediment and that between T 1 and T 2 (B) represents late pleistocene series, the interbed of land and marine facies sediment and the stratum (C) below T 2 represents middle pleistocene series. The interface between A and B is unconformable. Above mentioned sedimentary body is located up in B stratum, and below it there is a buried paleo river dated 14 C 26 820±2 380 aBP. It is inferred that the buried paleo delta is constructional formed during regressive period of late pleistocene. In addition, Close to the No.59 station, there are 3~4 channels with dissected filling reflection configuration, which are branches of a large buried paleo river with progradational bedding and sedimentary and geomorphological features in river mouth delta. Analysing of core 92 1 near the No.59 station shows that foraminifera assemblage and Sr/Ba are possessed with the feature of depositional environment from river mouth to nearshore. This proves further that the sedimentary body with progradational reflectional configuration is a river mouth delta. Result of mineral analysing shows that mineral assemble in the delta sediment consists mainly of Amphibole, Epidote, Timenit, Biotite and Carnet. The content of Carnet is higher than that of the sediment from Changjiang River, and most of Amphibole crystals have no inclusion. Above feature can be distinguished not only from that of the sediment from Changjiang River but also from that of Yalujiang. It is thus clear that mineral association feature in the delta sediment is similar to that from the Huanghe River. Obviously, the delta represents buried paleo Huanghe River delta formed during regressive period of late pleistocene. Finding of Buried paleo Huanghe River delat shows that paleo Huanghe River flowed on the south Yellow Sea shelf during late pleislocene.
出处
《地理学报》
EI
CSSCI
CSCD
北大核心
1998年第3期238-244,共7页
Acta Geographica Sinica
基金
国家自然科学基金
关键词
南黄海
埋藏
古三角洲
晚更新世
the south Yellow Sea, late pleistocene, buried paleo delta
