改进的特殊地质单元综合方法——以岩脉为例

An Improved Generalization Method for Special Geological Unit:A Case Study on Dyke

岩脉总是与矿脉密切共生,对于揭示区域地质演化过程、指导找矿工作具有重要意义,但在地质图自动综合过程中,由于岩脉出露规模较小,通常被合并处理。针对地质图综合过程中岩脉信息丢失问题,提出了地质图综合过程中基于地理事实的岩脉综合方法。首先根据连续性原则,识别潜在同源的岩脉组,再推理演绎地质过程,对岩脉进行同一性判断,对岩脉进行初步合并;其次,在开方根定律的基础上,确定相应比例尺地图的载负量及面积阈值,并根据计算结果对岩脉进行取舍;最后,简化岩脉的外部轮廓以及内部结构,避免制图比例尺变换过程中导致的岩脉与其他地质单元之间的邻近冲突问题,从而实现地质图的岩脉综合处理。试验结果与现有小比例尺地质图对比表明:所提出的岩脉自动综合方法较合理,可以在保留地层岩性特征、地质构造特征的条件下,有效避免岩脉的完整性被破坏,综合过程受人为因素的影响较小。该方法为地质图综合过程中特殊地理要素高效处理提供了一个新的思路。

Dykes are always closely coexisting with ore veins in deposit,and it is of great significance in reveling regional geological evolution process and guiding prospecting work.During the process of geological mapping and geological map synthesis,dyke is often neglected or integrated with general geological unit because of its relatively small exposure scale.In veiw of the loss question of dyke information in geological map synthesis,a generalization method of dyke based on geographical fact during the geological generalization process is put forward.Firstly,based on the continuity principle,the potential homologous dyke groups are identified,through the deduction of geological evolution process,the homologous judgement of dykes is conducted and dykes are amalgamated preliminarily.Then,based on the square root law,loading capacity and area threshold of the maps with different mapping scale are calculated,so as to determine dyke retention or abandonment.Finally,the outer shape and internal construction of dykes are simplified,so as to avoid the adjacent conflict problem between dykes and other geological units in the process of mapping scale transformation,therefore,dykes generalization process of geological map is realized.The comparison results of test and existing geological maps with small scale show that the proposed automatic dyke generalization method is more reasonable,the dyke integrity can be effectively avoided under the condition of retaining the stratigraphic lithological characteristics and geological tectonic characteristics,and the generalization process is less affected by human factors.The above study results further indicated that a new ideal for the processing of special geographical elements during the generalization process of geological maps is proposed.