沉积岩粒度分析和石英表面结构特征及其与沉积环境的关系

对粒度分析资料进行各种统计处理来研究沉积环境的水动力条件,前人已做过许多工作。作者将现代沉积物与大庆的古代沉积物的粒度分析数据进行了对比,以研究其沉积环境。

GRAIN-SIZE DISTRIBUTION AND SURFACE TEXTURE OF QUARTZ GRAINS IN SEDIMENTARY ROCKS AND THEIR RELATION TO SEDIMENTARY ENVIRONMENT

The grain-size analysis of modern and ancient sediments and the treatment of data by Folk’s formula give the following parameters: the standard deviation (δ1), mean size (Mz), kurtosis (Kg), skewness (SK1), simple skewness measure (αs) and simple sorting measure (Sos). Using these grain parameters we constructed the log-probability curves and scattered diagrams of both Sk1-δ1, and αs-Sos. According to the calculation after Sahu’s discriminant and the synthetic analysis of the data, four types of sedimentary environments wear established as follows: (1) deltaic distributary mouth bars arenaceous sediment (sample no. 1,5 and 8), (2) fluvial sediment (sample no.6), (3) delta front arenaceous sediment (sample no. 10), and (4) beach arenaceous sediment (sample no. 2 and 3).Moreover, the surface features of quartz grains in the samples were studied under a scanning electron microscope. The resulted environmental interpretation conincides fairly well with that derived from grain-size analysis, suggesting that the combination of two approaches mentioned above is an important and effective way to analyse the sedimentary environments, especially to the reconstruction of the ancient sedimentary environment.