论文部分内容阅读
近年来,黄河上游宁夏-内蒙古河段(简称宁蒙河段)河道淤积日益严重,辨识该河段的粗泥沙来源已成为该河段开发与治理的前提。重矿物耐磨蚀、稳定性强,能较多地保留其母岩的特征,因此常被用于物源示踪分析。对黄河宁蒙河段河道27个样品点的粗泥沙重矿物特征进行分析研究,表明该河段粗泥沙重矿物以性质不稳定的角闪石、较稳定的绿帘石、赤褐铁矿为主,稳定矿物除刚玉、钛铁矿外,锆石、金红石、黄铁矿、电气石含量极少。稳定系数法计算结果表明在河东沙地河段、乌兰布和沙漠河段以及十大孔兑河段之间稳定系数最低,几乎接近于0,说明在这3个地区河道粗泥沙源于附近沙源不同形式的汇入。本研究区ZTR指数极低,平均只有0.0071,说明黄河宁蒙河段泥沙重矿物成熟度低,淤积的泥沙并未经过长途的搬运堆积,而是来自当地沙源的汇入。相关系数法给出了3种不同性质的矿物组合类型,分别指示了不同的母岩类型和物源环境。
In recent years, the siltation of the channel in Ningxia-Inner Mongolia section of the upper reaches of the Yellow River has become more and more serious. Identifying the source of coarse sediment has become the prerequisite for the development and management of this section. Heavy mineral abrasion resistance, strong stability, can retain more of its parent rock characteristics, it is often used for source tracking analysis. The characteristics of coarse sediment heavy minerals in 27 samples of Ningmeng reach of the Yellow River are analyzed. It is shown that the coarse sediment heavy minerals in the reach of the river are unstable hornblende, stable emeraldite, Mine mainly stable minerals except corundum, ilmenite, zircon, rutile, pyrite, tourmaline content is minimal. The results of the stability coefficient method show that the stability coefficient is the lowest between the Ulan Buh desert and the Ulan Buh Desert and the ten major Konghe rivals, which is close to 0, indicating that the coarse sediment in the three areas of the river originates from Sand source near the different forms of import. The ZTR index in this study area is extremely low, with an average of only 0.0071, indicating that the sediment heavy minerals in the Ningxia-Mongolia section of the Yellow River are low in maturity. The silt sediment has not been transported and accumulated for long distances but imported from local sand sources. Correlation coefficient method gives three different types of mineral assemblages, indicating different types of parent rock and source environment.