摘要
In this paper,the age and sedimental environment of the lacustrine strata in the Haojiayao section which is ca.47 m thick have been studied mainly.WEIGHT: normal; WORD-SPACING: 0px; TEXT-TRANSFORM: none; COLOR: rgb(51,51,51); TEXT-INDENT: 0px; LINE-HEIGHT: 21px; FONT-STYLE: normal; FONT-FAMILY: Verdana, Arial, Helvetica, sans-serif; WHITE-SPACE: normal; LETTER-SPACING: normal; BACKGROUND-COLOR: rgb(255,255,255); FONT-VARIANT: normal; WIDOWS: 2; ORPHANS: 2; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">The results indicate the closed environment of the lake,and the Yellow River maybe did not pass through the Hetao Basin yet,also indicate that the lacustrine deposition stopped about 100 kaB.P.and turned to develop the eolian loess in the Togtoh region.