摘要
通过对东秦岭及相邻华北和扬子克拉通区开展区域地球化学研究,并取得大量资料和包括区域地壳和上地幔元素丰度估值的各项成果的基础上,本文对研究区(总面积1.6×10~5km^2)地球化学分区和地球化学图的编制进行了探索,提出了如下地球化学分区原则:鉴于地球化学省的特征,根本上是由区域上地幔化学组成特殊性所决定的,故地球化学省的划分必须以区域岩石圈,尤其上地幔的化学组成差异为依据,在一个地球化学省内划分地球化学区的标志应为地壳化学组成上的差异,后者是不同地球化学区内地质构造历史不同的反映,一个地球化学区内地球化学场的特殊性主要取决于各场内不同地质作用产物的地球化学特征,所以后者应为划分地球化学场的标志,一个地球化学场内的地质-地球化学过程,随着条件或物源的侧向变化,而发生分异,并导致具有不同特征的地球化学小区的形成,据此将研究区划分为2个地球化学省、4个地球化学区和分属于3种地球化学场的42个地球化学小区,最后编制了区域地球化学图,讨论了地球化学分区的主要特征。
The paper deals with geochemical subdivision and mapping of East Qinling and its adjacent North China and Yangtze cratons on the basis of the data, including estimations of the regional crust and upper mantle compositions. It is suggested that geochemical provinces should be determined according to the difference in geochemical characteristics of the litho-sphere and of the upper mantle in particular, because the chemical specificity of the regional upper mantle decides finally the compositional features of a geochemical province. In a geochemical province geochemical domains are suggested to be determined on the basis of the difference in geochemical characteristics of the regional crust, which are the reflection of the different geologic-tectonic evolution of geochemical domains. The peculiarities of geochemical fields in one geochemical domain depend mainly on the geochemical characteristics of products of different geological processes in the fields,so the latter can serve as a criterion to sub- divide a geochemical domain into geochemical fields. Geologic-geochemical processes in one geochemical field with lateral changes of conditions or material sources can differentiate to form geochemical subfields with different chemical characters. According to the suggested criteria the studied region is subdivided into two geochemical provinces, four geochemical domains and forty two geochemical subfields which belong to three different types of geochemical fields. Finally, the regional geochemical map is made and the main characteristics of the geochemical subdivision are discussed.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
1993年第4期463-476,共14页
Earth Science-Journal of China University of Geosciences
关键词
地球化学
区划
制图
东秦岭
geochemical subdivision, geochemical province, geochemical domain, geo-chemical field, geochemical subfield.
