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本文运用电子探针和氧同位素测试等手段,分析了和田河流域沙物质及某些有关基岩所含角闪石的种类、普通角闪石的化学成分和石英的δ~(18)O值。沙物质和岩浆岩(钾长花岗岩)在所含角闪石种类以及普通角闪石化学成分上的差异性明显大于相似性,说明后者为前者提供的角闪石有限。另外,沙丘沙含有多种变质成因的角闪石。产生这种现象的合理解释是:变质岩风化产物是沙的重要物源。沙物质中石英δ~(18)O值介于变质石英氧同位素成分范围,并且粒度愈细的石英,δ~(18)O值愈高。根据基岩中云母片岩所含石英颗粒最细、δ~(18)O值最高的特点判断,细沙物质在风扬过程中混入了较多的高δ~(18)O值细粒变质石英。
In this paper, by means of electron probe and oxygen isotope test, the types of amphiboles contained in the sandstones and some related bedrock of the Hetian River Basin were analyzed. The chemical composition of the amphiboles and the δ 18 O values of quartz . The differences in the chemical composition of the amphibole type and general amphibole between the sandy material and magmatic rocks (potash-bearing granites) are significantly greater than those of the similarities, indicating that the latter provides the former with limited amphiboles. In addition, dune sand contains a variety of metamorphic amphiboles. A reasonable explanation for this phenomenon is that metamorphic weathering products are an important source of sand. The δ 18 O values of quartz in sand matter range from the oxygen isotopic composition of metamorphic quartz, and the higher the δ 18 O value is, the finer the quartz grain size is. According to the finest quartz particles contained in mica schist in bedrock and the highest δ 18 O values, fine sand metamorphic quartz with high δ 18 O values during the process of aeration .