风化作用对彩色丘陵泥岩颜色变化的影响

Effect of Weathering on Color Change of Colored Mudstone in Hilly Area

为探究岩石颜色与风化作用的关系,以兰州猪驮山彩色丘陵的白垩系不同颜色风化泥岩和新鲜泥岩为研究对象,通过XRF、SEM和色度测试,研究风化前后泥岩色度的变化规律。结果表明,风化泥岩的亮度L、红度a、黄度b值大于新鲜泥岩,不同颜色泥岩的色度参数有一定规律;泥岩样品经历的化学风化作用较弱,物理风化对结构的改造是影响泥岩颜色变化的重要因素;色度参数的变化可能与孔隙形状、排列状态及表面粗糙度有关。

In order to explore the relationship between rock color and weathering,this paper takes the weathered mudstone and fresh mudstone of different colors of Cretaceous in Zhutuoshan color hills of Lanzhou as the research object,studies the change rule of mudstone color before and after weathering through XRF,SEM and chroma test.The results show that the brightness L,redness a and yellowness b of weathered mudstone are larger than that of fresh mudstone,the chroma parameters of different color mudstones have certain rules.The mudstone samples experience weak chemical weathering,and the structural modification of physical weathering is an important factor affecting the color change of mudstone.The change of chromaticity parameters may be related to the shape of pores,arrangement state and surface roughness.