作　　者： ; ; ; ;

机构地区： 兰州大学资源环境学院

出　　处： 《海洋地质与第四纪地质》 2013年第4期103-112,共10页

摘　　要： 通过对毛乌素沙漠南缘萨拉乌苏河流域滴哨沟湾剖面沉积物粒度、有机碳含量(TOC)、碳酸盐含量、无机碳酸盐碳氧同位素组成等分析测试,在已有的大量年代测定数据基础上,重建了该地区末次冰期晚期到中全新世期间的古环境。分析表明,11 000～9 950aBP滴哨沟湾地区气候干凉,萨拉乌苏河受陕北高原降水和当地冰溶地下水补给;9 950～9 100aBP为全新世初温度、降雨增加时期,有效湿度较高,滴哨沟湾湖泊开始形成;9 100～5 850aBP气温继续上升,降雨增加,但相对湿度减小,该时期是滴哨沟湾湖泊发育最大时期,湖泊水体滞留时间较长;5 850～5 100aBP气温和降水开始下降,湖泊收缩;5 100～4 700aBP期间温度和降水继续下降,湖泊环境逐渐转变为沼泽环境;4 700～4 500aBP期间滴哨沟湾沙漠化,形成了古流动沙丘沙沉积,干旱化加强;而在4 500～4 380aBP时又一次短暂的温湿气候,在沙丘表层钙板隔水层之上形成了短暂的小规模积水;自4 380aBP之后,滴哨沟湾地区沙漠化,干旱状况持续到现在。 Sediment grain size,organic carbon content（TOC）,carbonate content and stable carbon and oxygen isotopes of carbonates in the Dishaogouwan section on the south edge of the Mu Us desert in Inner Mongolia were sludied in this paper.Age data were used to establish an age model for this section.All the sedimentary and geochemical paleoenvironmental proxies were used to reconstruct the palaeoenvironmental changes since 11 000 aBP,to 4 380 aBP,early to mid Holocene in this area.During the period from 11 000 aBP to 9 950 aBP,the study area was cool and dry.Precipitation in the south north part of Shanxi Loess Plateau and the water from melted Dishaogouwan frozen stratum were the main replenishment water for the Salawusu cathment.During the period of 9 950~9 100 aBP of early Holocene,temperature and precipitation increased with a high effective humidity,and the Dishaogouwan lake came into being.From 9 100 aBP to 5 850 aBP,temperature and precipitation continued to increase but effective humidity was a little lower,while the lake developed to its maximum and lasted for a long time.From 5 850 aBP to 5 100 aBP,temperature and precipitation started decreasing and the lake shrank at the same time.From 5 100 aBP to 4 700 aBP,palaeodune formed in this area under dry climate.There was a short period of temperature and rainfall rising during 4 500~4 380 aBP,and a small lake formed over a carbonate impermeable layer.Desertification has prevailed under the dry condition since 4 380 aBP up to present.

关 键 词： 河湖相 粉砂黑垆土 地球化学环境指标 全新世早中期 滴哨沟湾

领　　域： [天文地球] [天文地球]