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碳酸盐矿物是黄土的重要组成部分,是古环境重建的重要指标之一。通过对地处西风区的新疆伊犁盆地昭苏黄土剖面的全岩样品和分粒级样品的X射线衍射测试,分析了其碳酸盐矿物组成,利用麦夸特算法计算了碳酸盐矿物的含量。综合碳酸盐矿物的含量、粒径分布及风化特征等因素,对其古环境意义进行了辨识,从而建立了该剖面末次冰期以来碳酸盐矿物记录的古气候环境变化序列。结果表明:昭苏剖面中原生碳酸盐矿物(方解石和白云石)含量占主导地位,次生方解石对样品中总方解石含量的贡献较少;白云石含量可能与亚轨道尺度冷暖交替导致的西风环流强度变化有关;方解石含量的变化可能指示了西风区降水量的变化;碳酸盐矿物含量揭示了昭苏地区在末次冰期时气候冷湿,在全新世时气候暖干。
Carbonate mineral is an important part of loess and is one of the important indicators of paleoenvironment reconstruction. Based on the X-ray diffraction tests of the whole rock samples and the classified samples of the Zhaosu Loess Section in the Yili Basin, located in the west wind region, the carbonate mineral compositions were analyzed. The contents of carbonate minerals content. According to the content, distribution of grain size and weathering characteristics of carbonate minerals, the paleoenvironmental significance of the carbonate minerals has been identified, and the sequence of paleoclimate changes recorded by carbonate minerals since the last glacial period has been established. The results show that the content of primary carbonate minerals (calcite and dolomite) in Zhaosu section is predominant, and the contribution of secondary calcite to total calcite content in samples is less. The dolomite content may be related to the westerly The change of calcite content may indicate the variation of precipitation in the westerly area. The carbonate mineral content reveals that the climate in the Zhaosu region was cold and wet during the last glacial period and was warm during the Holocene.