【摘要】：下蜀黃土的成因和物源一直是學術(shù)界研究的熱點。對南京周家山下蜀黃土的石英粒度和石英表面微結(jié)構(gòu)進行分析,結(jié)果顯示:粉砂粒級石英顆粒(5~50μm)占絕對優(yōu)勢;20μm組分平均含量為42.76%,30μm組分平均含量為62.98%;粒度分布曲線和累積曲線總體具有顆粒偏細,呈正偏態(tài),分選較差,峰形尖銳,雙峰曲線不對稱的特征;粒級—標準偏差曲線呈"雙峰"分布,兩個明顯的標準偏差峰值分別出現(xiàn)在7.962 1μm和39.905 2μm。石英顆粒表面形態(tài)主要以次棱角狀為主;表面機械結(jié)構(gòu)具有豐富的蝶形坑、曲脊、貝殼狀斷口,部分表面出現(xiàn)平行節(jié)理面、V形坑;不同粒級組分表面形態(tài)和機械結(jié)構(gòu)特征存在差異。分析表明,南京周家山下蜀黃土屬典型風成成因堆積物,是多源區(qū)物質(zhì)高度混合搬運堆積的結(jié)果。
[Abstract]:The origin and origin of Xiashu loess has been a hot topic in academic circles. The quartz particle size and quartz surface microstructure of Xiashu loess in Zhoujiashan, Nanjing, were analyzed. The results showed that silt grade quartz particles (5 ~ 50 渭 m) were dominant, and the average content of 20 渭 m component was 42.7630 渭 m, and the average content of 20 渭 m component was 62.98 渭 m. The particle size distribution curve and the cumulative curve have the characteristics of fine particle size, positive bias, poor sorting, sharp peak shape and asymmetric bimodal curve. The grain grain-standard deviation curve showed a "double peak" distribution, and two obvious standard deviation peaks appeared at 7.962 渭 m and 39.905 2 渭 m, respectively. The surface morphology of quartz particles is mainly subangular-shaped, and the mechanical structure of the surface has abundant butterfly pits, curved ridges, shell-like fractures, parallel joints and V-shaped pits on some surfaces. The surface morphology and mechanical structure of different particle size components are different. The analysis shows that the loess in Zhoujiashan, Nanjing is a typical aeolian deposit, which is the result of high mixing transport and accumulation of materials in multi-source area.
【作者單位】： 華東師范大學地理科學學院地理信息科學教育部重點實驗室;
【基金】：國家基礎(chǔ)科學人才培養(yǎng)基金(J1310028) 國家自然科學基金項目(41371032)~~
【分類號】：S151.9
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本文編號：2425368