The sedimentary sequence of the upper 4 m deposits in the Huanghe Harbour Pit is as follows, 1, Distributary mouth bar deposits formed before 1964; 2. lower delta plain (tidal flat) and subaqueous delta lateral deposi...The sedimentary sequence of the upper 4 m deposits in the Huanghe Harbour Pit is as follows, 1, Distributary mouth bar deposits formed before 1964; 2. lower delta plain (tidal flat) and subaqueous delta lateral deposits formed in the period of 1964-1972; 3. deposits of crevasse splay and distributary channel near mouth, formed in the period of 1972-1974; 4. tidal flat deposits formed in the period of 1975-1984. The sequence shows superimposition of sedimentary environments parallel to coastline.展开更多
黄河三角洲作为自然河流体系形成的大型河控三角洲,研究其地层结构可更好地理解河控三角洲的层序框架、河流改道与海平面升降等。本文主要基于黄河三角洲上GJ1钻孔沉积物的粒度以及测年数据,结合前人成果,利用岩性地层学、年代地层学等...黄河三角洲作为自然河流体系形成的大型河控三角洲,研究其地层结构可更好地理解河控三角洲的层序框架、河流改道与海平面升降等。本文主要基于黄河三角洲上GJ1钻孔沉积物的粒度以及测年数据,结合前人成果,利用岩性地层学、年代地层学等方法,划分了GJ1钻孔的沉积相,重点是全新统。GJ1钻孔78m长的岩心,形成年代为60ka B.P.至今,沉积相自下而上依次为(1)三角洲-河流-三角洲沉积(49.2~78.0m);(2)河流沉积(45.9~49.2m);(3)滨海近岸-河流沉积(24.6~45.9m);(4)河流沉积(19.4~24.6m);(5)全新世河流-滨海-三角洲前缘-河流-分流间湾与河流沉积(19.4m以浅),其中4.5m以浅为1917—1926年期间黄河行水的河床及废弃河道沉积。此外本文尝试将粒度数据与全新世古气候变化记录进行对比,发现全新世相对冷期GJ1孔平均粒径较粗,在相对暖期平均粒径较细的整体特征。且可以识别出6 500~6 000cal yr B.P.,4 200~3 800cal yr B.P.,3 500~2 500cal yr B.P.三次明显的北半球冰盖扩张,两极变冷,赤道变干的气候事件。展开更多
文摘The sedimentary sequence of the upper 4 m deposits in the Huanghe Harbour Pit is as follows, 1, Distributary mouth bar deposits formed before 1964; 2. lower delta plain (tidal flat) and subaqueous delta lateral deposits formed in the period of 1964-1972; 3. deposits of crevasse splay and distributary channel near mouth, formed in the period of 1972-1974; 4. tidal flat deposits formed in the period of 1975-1984. The sequence shows superimposition of sedimentary environments parallel to coastline.
文摘黄河三角洲作为自然河流体系形成的大型河控三角洲,研究其地层结构可更好地理解河控三角洲的层序框架、河流改道与海平面升降等。本文主要基于黄河三角洲上GJ1钻孔沉积物的粒度以及测年数据,结合前人成果,利用岩性地层学、年代地层学等方法,划分了GJ1钻孔的沉积相,重点是全新统。GJ1钻孔78m长的岩心,形成年代为60ka B.P.至今,沉积相自下而上依次为(1)三角洲-河流-三角洲沉积(49.2~78.0m);(2)河流沉积(45.9~49.2m);(3)滨海近岸-河流沉积(24.6~45.9m);(4)河流沉积(19.4~24.6m);(5)全新世河流-滨海-三角洲前缘-河流-分流间湾与河流沉积(19.4m以浅),其中4.5m以浅为1917—1926年期间黄河行水的河床及废弃河道沉积。此外本文尝试将粒度数据与全新世古气候变化记录进行对比,发现全新世相对冷期GJ1孔平均粒径较粗,在相对暖期平均粒径较细的整体特征。且可以识别出6 500~6 000cal yr B.P.,4 200~3 800cal yr B.P.,3 500~2 500cal yr B.P.三次明显的北半球冰盖扩张,两极变冷,赤道变干的气候事件。
