Abstract:

Due to the long-term mining，the resource crisis in Xishan section of Linglong gold field is becoming more and more serious.The known main veins have been basically explored and mined by pit exploration，finding new resources has become an urgent need for mines.Through regional geological analysis and summary of metallogenic regularity，the veins in the ore-section are sorted out one by one，and it is found that the local geological structure is inconsistent with the regional structural regularity.The researchers selected the 108# vein group with stable overall occurrence but large local changes to study the metallogenic regularity and tectonic movement regularity.Through the study of the movement law of the upper and lower plates of the 108# vein group and the mineralization of 108# vein group，it was found that the main vein of 108# vein is a reverse fault with obvious displacement，while its branch vein 96#，vein 98# and vein 107# are tensile-torsional or tensile faults with no obvious displacement.At the same time，there are obvious differences in mineral structure and mineral composition，so it is speculated that there are a series of structures in the footwall of the western main vein of 108# vein，which are consistent with the structural laws of the branches in the footwall and move downward with the footwall.Therefore，108# blind branches were found in the blind zone prospecting in the speculated area at -50 elevation level of Xishan ore section.The exploration of 108# veins verified the study of this metallogenic regularity and established a branch prospecting model，that is，the upper and lower walls of the main vein of 108# vein have ore-hosting secondary structures corresponding to each other with nearly parallel arrangement and nearly equal spacing distribution，and the blind veins of 108 2# veins and 108 3# veins were successfully explored by this model.At present，the proven metal amount is 2.4 tons，which prolongs the service life of the mine.It is worth mentioning that after the upper and lower wall branches of 108# main vein were dislocated by the fault of 108# main vein，the lower branch vein and the upper branch vein experienced different metallogenic periods.In the later period，the main vein of the 108# vein blocked the ore-forming hydrothermal solution，so that the ore-bearing faults of the lower plate could form better orebodies，and the mineralization of the footwall branches vein at the far end of 108# main vein also confirmed this point.According to the results of this prospecting，the same tectonic regularity and metallogenic environment have been found in other vein groups such as 53#，55# vein group，which points out the direction for the next prospecting.

Key words: ore-controlling branch vein, ore-controlling structure, metallogenic environment, blind orebody, resource crisis, Linglong gold mine