摘要
里下河地区浅部沉积物多为全新世中、晚期堆积,多数地区缺失全新世早期沉积。沉积物以淤泥质亚粘土、亚粘土、亚砂土,粉砂质淤泥、淤泥质粉砂、淤泥及泥炭为特征。沉积前的古地貌为四周高、中间低的碟形盆地。古气候经历了温湿—暖湿—温湿—温干的变化过程。区内曾有两次海侵,第一次海侵发生在全新世早中期,范围几乎遍及全区;第二次海侵发生在全新世晚期,规模小、范围窄、时间短,为海水沿江河倒灌、回溯形起。该区古环境自全新世以来经历了浅水海湾—古泻湖—湖沼地及平原的演变过程,最终形成现今河湖稠密的低凹平原。
The shallow sediments in Lixiahe region （Xinghua-Taizhou） are the accumulation of middle and late Holocene Epoch, the early sedimentation was absent in most of the areas. The sediments are mostly muddy silty clay, silty clay, sandy sludge, muddy sand- stone, sludge and peat. Before sedimentation, the old landform was dishing basin with high in the milieu and low in the center. The paleoclimate underwent a process of humid warm to warm humid and humid warm to dry warm. Twice marine transgressions occurred in the study area, the first marine transgression occurred in the early and middle periods of Holocene Epoch, with a range of almost the whole region ; the second marine transgression occurred late period of Holocene Epoch, with a small scale, narrow range and short time period, and brought about by river reverse flow and retrospect. The old environment underwent an evolvement of shallow sea gulf, paleolagoon, limnetic land and plain, and eventually formed the present low-lying plain with dense rivers and lakes.
出处
《江苏地质》
2007年第2期101-107,共7页
Jiangsu Geology
关键词
浅部
沉积特征
古气候
环境演变
江苏
Shallow lands
Sedimentation properties
Paleoclimate
Environmental evolution
Jiangsu
