【摘要】 南黄海陆架在第四纪具有海侵—海退交替发生、海陆相地层交互沉积的特点,沉积相及其分布主要受海平面变化与古河流及其三角洲的控制。对南黄海西部地区采集的5600km浅层地震剖面进行了层序划分与解释,得到以下认识:(1)早更新世晚期以来的南黄海地层可分为U1—U14共14个地震地层单元,组成6个地震层序,代表了6次大规模海侵-海退过程,其中氧同位素5期海相地层在该地区最发育;(2)根据全新世地层厚度变化,将该区分为6个沉积区:东部弱沉积区、中北部沉积发育区、海州湾外侵蚀区、废黄河口沉积区、射阳河口岸外侵蚀区和苏北浅滩沉积区;(3)氧同位素6期至2期,南黄海西部陆相层内发育了3期埋藏古河道:上层古河道发育于氧同位素2期,古长江水系、古黄河水系分别自南黄海南部、北部流入古黄海;中层古河道发育于氧同位素4期,仅分布于近岸地区;下层古河道发育于氧同位素6期,分布于123°E以西地区,其南部古河道应为古长江水系,规模较大,其北部古河道规模较小,分布范围有限;(4)古长江第四纪早期在古黄海入海,古黄河在氧同位素5期中后期也开始自古黄海入海,其古河道发育具有一定继承性,后期发育规模逐渐增大;(5)气候温暖的高海面时期发育于构造沉降区的早期古三角洲规模较大,气温降低后河流追随海平面下降而发育的后期三角洲规模较小。氧同位素3期至5期,古长江水系在南黄海西南部发育多期古长江三角洲,古黄河水系在南黄海北部则主要发育两期古黄河三角洲;(6)晚更新世晚期、全新世初期的海侵过程中,南黄海地区发育了古河口沙坝、古潮沟相等滨海沉积。更多还原

【Abstract】 The character of Quaternary continental shelf in the South Yellow Sea is transgressive-regressive cycles and alternating continental-marine strata,the sediment facies and distribution are controlled mainly by sea-level changes,paleo-channel and its delta.Based on the 5 600 km shallow seismic profile acquired in western South Yellow Sea recently,we distinguished and interpreted the stratigraphic sequences,and following conclusions are made:(1)The strata of South Yellow Sea since early Pleistocene are divided into fourteen seismic units,and composed of six seismic sequences,representing six transgressive-regressive cycles,and the strata developed during oxygen-isotope stage 5 widespread mostly.(2)The study area can be divided into six deposit zones by Holocene strata thickness:eastern weak depositional zone,mid-north depositional zone,depositional zone out of Haizhou Bay,abandoned Yellow River mouth depositional zone,erosional zone out of Sheyang River,and Subei shoal depositional zone.(3)During oxygen-isotope stage 6 to 2,three paleo-channel stages are found in the area:the upper layer was developed during oxygen-isotope stage 2,the paleo-Yangtze and paleo-Yellow River systems flowed into southern and northern paleo-Yellow Sea;the middle layer was developed during oxygen-isotope stage 4,and found in the coastal area;the lower layer was developed during oxygen-isotope stage 6,distributed west of 123°E.The southern paleo-channel on broad scale should belong to the paleo-Yangtze River,and the northern paleo-channel is distributed in limited range on small scale.(4)Paleo-Yangtze River flowed into paleo-Yellow Sea in early Quaternary,and paleo-Yellow River flowed into paleo-Yellow Sea in mid-late late Quaternary.To some extent,their paleo-channel distributions were inherited,and the scale of late stage more widespread.(5)The early delta developed during high sea-level warm climate was large,and late delta developed when sea-level lowered was small.During oxygen-isotope stages 3 to 5,several stages of paleo-deltas were developed in southern South Yellow Sea by paleo-Yangtze River,and two stages of paleo-deltas were developed in northern South Yellow Sea by paleo-Yellow River.(6)During transgression between late Pleistocene and early Holocene,paleo river-mouth sandbars and buried tidal creeks were developed.更多还原