Constraints on Representative Samples from
详细信息
- 责任者：Yang Zongfeng (State Key Laboratory of Geological Processes and Mineral Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Luo Zhaohua
- 刊名：Acta Scientiarum Naturalium Universitatis Pekinensis
- 出版年：2010
- 卷期：46(6)
- 关键词：花岗岩 ; granite ; 实际矿物分析 ; modal mineral analysis
- 页码：p.951-959
- 图表：4 illus., 5 refs.
- 分类号：0700
- issnNo：ISSN0479-8023
- isbnNo：CN11-2442/N
摘要
In order to obtain the size of representative samples and its constraints, the relationships of the representative samples with crystal contents and crystal size are preliminarily discussed by statistical simulations of the holocrystalline rocks’ texture and the idealized granitic compositions. The maximum possible difference between the original and measured crystal contents of samples, and the size of representative samples are determined under the variations of crystal contents and size. The greatest difference between the original and measured crystal contents of samples can be obtained by counting the number of phenocrysts across the sections of samples. The size of representative samples can be acquired by using the average crystal size. The deviation between the measured and original crystal contents are much more higher for coarsegrained samples with the same sample size. The largest representative samples are needed when the crystal content reach 20% for phenocrysts or coarse-grained minerals in equigranular texture. Finally, two examples including the Mapeng and Fangshan intrusions are used to examine the validity and practicability.