陆相CaCO3的环境相模式讨论

本文认为陆相CaCO_3是喀斯特过程中的堆积物,它包括地表的石灰华类和洞穴中的洞石。这是一大类第四纪沉积物,其堆积、结构、颜色、形态受堆积环境总效应控制,涉及到古环境、古动力和能流诸多因子,构成了重要的地质环境信息库。本文从堆积环境,动力能级、形态成因的整体性、系统性上讨论,提出了陆相CaCO_3堆积的环境相多模式的认识。

MODEL OF ENVIRONMENTAL FACIES OF CONTINENTAL CaCO_3

Continental CaCO3 is a sediment formed during karst process. It is one of the sedimentary types in Quaternary period. Continental CaCO3 consists of speleothems in caves and tufas on land surface. Because continental environment is not stable and its strength of power is fluctuating, continental CaCO3 has many model systems of facies. According to sedimentary environment, the cave environment is divided into six facies models and the surface tufa environment is divided into four climatic environmental areas, six facies models and fifteen subfacies models, and mechanical energy current of three energy levels are discussed in the article. It is emphasized that sedimentation of continental CaCO3 is controlled by whole effects in environmental field, i. e.,1. isoion effect of Ca+2, hydra-tion energy effect of Ca+2 and Mg+2, lattice energy effect and pH effect in environmental chemical field, 2. temperature difference effect, and current velocity effect in physical-chemical field, and 3. bio-field effect. We think that most of continental CaCO3 is the overlap of several models, althoughthere is single model in nature. According to the study of continental CaCO3 in China, some questions of environmental changes, such as climatic fluctuation, hydrographic change, shrink of western lakes, change of sea-level, fossil earthquake and neotectonics> are discussed in the article.