中国东北浅覆盖区地质填图物化探信息协同辅助技术

Geochemical and Geophysical Information Integration Technology for Geological Mapping at Shallow Overburden Area in Northeast China

针对中国东北浅覆盖区地质露头少、填图效率不高、精确度和准确度较低的问题,开发了物化探信息协同辅助技术并应用于地质体类型的识别。在以覆盖层较薄、面积广大、物理风化为主、土壤位移较小为特点的东北森林沼泽浅覆盖区,利用土壤化学成分和航磁信息识别下伏地质体是可行的。基于这一前提,可将指定研究区划分为一定数量的统计单元,在各单元内,通过数学统计方法产生众数、宽度、变化频率、偏度、峰度等航磁特征参数并将其标准化,将化探指标酸度、碱度、钙含量、铝含量、钙镁含量、硅铝含量、镁铁含量、微量元素含量等特征参数标准化;然后采用逐级分类的方法,每级选择有效的物化探特征参数,在当前级别上实现单元划分并将数据分为不同数据集,在下一级别划分时重新有针对地选择参数,分别对各数据集进一步分类,直到分类结果对应较明确的地质填图单元,并最终编制出解译图。以黑龙江省大兴安岭地区某典型森林沼泽浅覆盖区为例进行了方法验证,将结果与已知地质信息比对分析,认为地质体单元识别结果与已知信息基本吻合,使得地质体类型识别更精确,边界更清晰,可为区域地质研究提供新线索。

Aiming at the difficulties of geological mapping at shallow cover areas Northeast China,such as fewer outcrops,lower efficiency,lower precision and accuracy,we developed a geophysical and geochemical information integration technology for geological body identification.It is suitable for the shallow cover area in Northeast China,where it is huge with the features of strong physical weathering and small soil displacement.In this method,the entire study area is divided into a number of statistical units,the regional aeromagnetic information in each unit is transformed into characteristic parameters,such as mode,interquartile range,frequency,skewness,kurtosis,and the regional geochemical information in each unit is transformed into the characteristic parameters,such as acidity,alkalinity,calcium content,aluminum content,content of calcium and magnesium,content of aluminum and silicon,content of magnesium and iron,and individual trace elements.Then,all the units are classified step by step based on their characteristic parameters to finally identify geological bodies.Taking somewhere in a typical shallow overburden area in Northeast China as an example,we applied this method.By comparing the results with the known geological information,the recognition results of geologic units are in good agreement with the known information.This method can provide richer geological information and new clues for regional geological research.