多体系微量元素地球化学对比中存在的问题及解决途径

在微量、稀土元素地球化学对比研究中,直观地根据蛛网图上曲线相似程度而得出的结论带有很大的主观随意性,可信度低。通过2个应用实例(云南北衙金矿床;江西相山变质岩),运用Q型逐步聚类分析及模糊聚类分析与蛛网作图相结合的对比研究方法,分别对云南北衙金矿的成矿物质来源和江西相山变质岩的地层单元归属问题进行了探讨,发现该方法可获得较多精细的、为蛛网图所隐匿的、但具有重要地质意义的地球化学信息,从而得出更为严谨、客观、并具有科学再现性的结论。

TRACE ELEMENT GEOCHEMICAL COMPARISION AMONG MULTIPLE GEOLOGICAL OBJECTS-PROBLEMS AND SOLUTIONS

Conclusions based on audio-visual similarity degrees of the distribution patterns of trace elements and rare earth elements in different geological objects are subject to individual researcher`s subjectivity and thus may have low reliability. Through two examples (the Beiya gold deposit in Yunnan Province and metamorphic rocks at Xiangshan in Jiangxi Province), by means of Q-type cluster analysis and fuzzy cluster analysis on trace elements and REE data and in combination with spidergram, the source of metallogenetic materials for the Beiya gold deposit in Yunnan Province and the stratigraphic designation of metamorphic rocks at Xiangshan in Jiangxi Province are discussed respectively in this paper. Using these analyses, we are able to obtain much finer geochemical information with significant geological implications hidden in the spidergram. Thus more strict and objective conclusions with scientific duplicity may be drawn when this method is used.