冀西北黄土钙质结核形态及其成因动力学特征与地层环境意义

论述了冀西北山间盆地区黄土钙质结核的个体特征及群体分布特点，结合地层的时代划分，总结了钙质结核的地层学意义：中更新统结核个体大，外形多呈块状，内部以均质结构为主，在剖面中常密集成层分布；上更新统结核个体较小，多呈姜状或球状，同心结构居多，分布较稀疏。根据钙质结核在盆地内的空间分布，提出形成钙核的ＣａＣＯ３成分部分可能来自于盆地边缘基岩区，按照结晶动力学原理对钙核的形成过程进行了分析，并在此基础上，对不同特征钙质结核的形成环境进行了讨论。

FORM AND GENETIC DYNAMICS CHARACTERISTICS OF CALCAREOUS CONCRETION IN THE LOESS OF NORTHWESTERN HEBEL PROVINCE AND ITS STRATIGRAPHY SIGNIFICANCE

The characteristics of individual and colony of calcareous concretion in the loess of Northwestern Hebei Province are discussed.Combined with the time divison of strata, the significance of stratigraphy is concluded in Middle Pleistocene Series, the individual is big and block outside,and its inside mainly shows homogeneous structure,and often seen closelyspaced layers int the section;in UpperPleistocene Series,it smaller,and appears ginger and spherical,which is dominated by concentric structure,and its distribution is sparse. Based on the spatial distribution of calcareous concretion in the basin,this paper proposes the CaCO3 compositions formed calcareous concretion probablely come from the basement rock in the margin of bash.According to the principle of crystallization dynamics, the formationprocess and environment of different calcareous concretion are analysed.