额济纳盆地GN100钻孔不同沉积相的粒度特征

内蒙额济纳盆地GN100钻孔的沉积相可划分为河流相、湖泊相、沼泽相及风成砂沉积。对该钻孔不同沉积相代表性 沉积物的粒度分析表明：额济纳盆地沉积物的粒度特征能够有效区分沉积环境和动力过程。河流相沉积物主要粒度组分为 粗砂，以滚动搬运为主，判别值Y为大于1；风成砂主要粒度组分为细砂，Y值范围主要在0附近；沼泽相也以细砂为主且 较风成砂更细，Y值主要为负值且小于风成砂；湖相粒度组分主要为细粉砂，以悬浮搬运为主，但不完全是静水悬浮搬 运，相比于静水沉积相对颗粒偏大，而Y最小，为小于-9。这些结果可以为区域沉积环境的准确解释提供参考。

Grain-sizeCharacteristicsofDifferentSedimentaryFaciesfrom theCoreGN100intheEjinaBasin

TheEjinabasin,locatedinthearidareainNWChina,underwentcomplicateddepositionalprocessesduringQuaternary. Basedoncharacteristicsofdifferentsedimentarystructures,a18mlongsedimentcorefromthecenteroftheEjinaBasincanbe divided into fluvial, aeolian, swamp and lacustrine sediments. The grain-size analysis shows that the depositional environment, transportdynamicsintheEjinabasincanbedistinguishedbycharacteristicofgrain-sizedistribution.Themajorgrain-sizecomponent offluvialsedimentwascoarsesandandYvaluewasgreaterthan1;themajorgrain-sizecomponentofaeoliansandwasfinesandandY valuewascloseto0;themajorgrain-sizecomponentofswampsedimentwasalsofinesandbutfinerthanaeoliansand,withanegative Yvalues;themajorgrain-sizecomponentoflacustrinesedimentwasfinesiltwhichwastransportedbysuspension,butdifferentwith settledowndepositinstandingwater,andYvalueswaslessthan-9.Theseresultsshowcharactersofgrainsizedistributioncanbe usedfordistinguishingdifferenttransportprocessesanddynamics,which,inturn,isabletoprovidecriticalinformationforaccurate interpretationofthedepositionalenvironmentchangeinthisarea.