黄河碎屑物质和中国西北沙漠/沙地存在物源联系吗?

Are Detrital Materials from the Yellow River Associated with Desert/Sandy Land Provenances in Northwest China?

在中国西北内陆分布着面积广大的沙漠/沙地,确定其物质来源对理解这些沙漠的形成和发育至关重要.尤其对腾格里沙漠、河东沙地、毛乌素沙漠、乌兰布和沙漠和库布齐沙漠的碎屑物质是来自远源的黄河还是近源源区的争议较大.鉴于此,对沙漠中广泛存在的碎屑钾长石进行了554颗原位Pb同位素分析,结合黄河上游已经发表的钾长石Pb同位素数据,判定二者之间是否存在物源联系.综合区域内已发表的物源示踪结果,表明黄河上游的碎屑物质对腾格里沙漠的影响主要集中在有限的局部区域,未深入到沙漠腹地;黄河上游物质和河东沙地、毛乌素沙漠、乌兰布和沙漠和库布齐沙漠不存在物源联系.中国西北内陆这些沙漠/沙地的物质主要以近源物质为主,是对早更新世以来青藏高原隆升和气候干旱的沉积响应.

There are large areas of desert/sandy land located in the interior of Northwest China.To determine their material origin is crucial to understand the formation and development of these deserts.Especially,it is controversial whether the detrital materials in Tengger,Hedong,Mu Us,Ulan Buhe and Kubuqi deserts and sand lands come from the distant Yellow River or the near source area.In view of this,it carried out in-situ Pb isotopic analyses of detrital K-feldspar grains(n=554)widely found in these deserts to determine whether there is a provenance relationship with the upper reaches of the Yellow River.Combined with the published Pb isotopic compositions of detrital K-feldspar from the upper Yellow River and provenance tracing results in the region,the results show that the detrital material from the upper Yellow River mainly affected the Tengger Desert in a limited local area,but did not penetrate into the desert hinterland.The material in the upper reach of the Yellow River is not related to Hedong sand land,Mu Us sand land,Ulan Buhe desert and Kubuqi desert.The material of these deserts/sandy lands in Northwest China was mainly derived from near source area,which is a sedimentary process response to the uplift of the Tibetan plateau and climatic drought since the Early Pleistocene.