{"title":"Geochemical dispersion evaluation by criterion-based backward elimination at the Glojeh polymetallic Au (Ag-Cu-Pb-Zn) vein deposit, NW Iran","authors":"F. Darabi-Golestan","doi":"10.1144/geochem2023-011","DOIUrl":null,"url":null,"abstract":"\n We applied the Backward Elimination (BE) method as a criterion-based iterative stepwise method to estimate the concentration of Au from the variables Ag, Cu, Pb, and Zn. We optimized the quadratic polynomial model (QPM) on various boreholes and trenches. The results indicate that the vertical zonation of Au is associated with Ag and Cu, along with their respective elemental functions Ag×Cu, Pb\n 2\n , Pb×Zn, and Zn\n 2\n . On the other hand, the lateral dispersion of Au is determined by Pb and Zn, along with the essential functions Ag×Zn and Pb×Zn. Zonation is in-depth and is indicated primarily by Zn rather than Cu and minor Pb, with Cu-Pb-Zn gradually extending upward at the upper levels. The vertical zonation trend describes the Ag<Au<Cu<Pb<Zn sequence from proximal to distal veins, with the near-surface zone exhibiting enrichment in Zn. At the Glojeh site, the host rock value, Ag×Cu, Zn\n 2\n , and Pb×Zn, were identified as strong indicators of the vertical occurrence of Au in the upper host rock, whereas Pb\n 2\n proved more suitable for the deeper boreholes. Cu→Pb→Zn demonstrates the enrichment trend from depth to the surface. The lateral kriging surface estimation confirms the dispersion pattern of elements revealed in-depth at Glojeh. Our aims with this approach were to reduce the cost of fire-assay analysis due to high precision estimation by associated variables and determine elemental interactions and the lateral or vertical dependencies of elements.\n","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":1.0000,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geochemistry-Exploration Environment Analysis","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1144/geochem2023-011","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
We applied the Backward Elimination (BE) method as a criterion-based iterative stepwise method to estimate the concentration of Au from the variables Ag, Cu, Pb, and Zn. We optimized the quadratic polynomial model (QPM) on various boreholes and trenches. The results indicate that the vertical zonation of Au is associated with Ag and Cu, along with their respective elemental functions Ag×Cu, Pb
2
, Pb×Zn, and Zn
2
. On the other hand, the lateral dispersion of Au is determined by Pb and Zn, along with the essential functions Ag×Zn and Pb×Zn. Zonation is in-depth and is indicated primarily by Zn rather than Cu and minor Pb, with Cu-Pb-Zn gradually extending upward at the upper levels. The vertical zonation trend describes the Ag
期刊介绍:
Geochemistry: Exploration, Environment, Analysis (GEEA) is a co-owned journal of the Geological Society of London and the Association of Applied Geochemists (AAG).
GEEA focuses on mineral exploration using geochemistry; related fields also covered include geoanalysis, the development of methods and techniques used to analyse geochemical materials such as rocks, soils, sediments, waters and vegetation, and environmental issues associated with mining and source apportionment.
GEEA is well-known for its thematic sets on hot topics and regularly publishes papers from the biennial International Applied Geochemistry Symposium (IAGS).
Papers that seek to integrate geological, geochemical and geophysical methods of exploration are particularly welcome, as are those that concern geochemical mapping and those that comprise case histories. Given the many links between exploration and environmental geochemistry, the journal encourages the exchange of concepts and data; in particular, to differentiate various sources of elements.
GEEA publishes research articles; discussion papers; book reviews; editorial content and thematic sets.