Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India
Geochemical alteration indexes viz. carbonate chlorite pyrite index, ishikawa alteration index, hashiguchi alteration index, chemical alteration index and silicification index are conventionally used to study the degree and type of alteration. Thin section microscopic and X-ray Fluorescence analysis...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-06-01
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| Series: | Journal of Asian Earth Sciences: X |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2590056022000147 |
| _version_ | 1818234183045087232 |
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| author | Pankajini Mahanta Sabyasachi Maiti |
| author_facet | Pankajini Mahanta Sabyasachi Maiti |
| author_sort | Pankajini Mahanta |
| collection | DOAJ |
| description | Geochemical alteration indexes viz. carbonate chlorite pyrite index, ishikawa alteration index, hashiguchi alteration index, chemical alteration index and silicification index are conventionally used to study the degree and type of alteration. Thin section microscopic and X-ray Fluorescence analysis got similar roles for alteration study. Due to sparse and expensive sampling, the regional depiction of alteration patterns and their quantitative analysis are usually unavailable for exploration geologists. Here, we provided an alternative remote proxy-based approach to map the degree and type of alteration on a large scale, using visible-near infrared and shortwave infrared bundles of WorldView-3 imagery. The chosen study area is sparsely vegetated Lawa gold deposit in the North Singhbhum Mobile Belt, India. Partial least squares regression (PLSR) modelling of geochemical alteration indexes with reflectance spectra was used to understand the spatial variation in the degree of alterations. The remotely derived alteration indexes can be linked with field and microscopic studies of Cu-Au mineralization. We found dominance of alteration processes in the following order: ferruginisation, silicification, sericitization and chloritization. Demarcated intensely hydrothermally altered zones are present near the exposed mineralized outcrop. In addition, we identified new alteration zones with ore phases as a plausible mineralized zone. |
| first_indexed | 2024-12-12T11:34:01Z |
| format | Article |
| id | doaj.art-1e66b33f0b774661bf2620f26b6c6c97 |
| institution | Directory Open Access Journal |
| issn | 2590-0560 |
| language | English |
| last_indexed | 2024-12-12T11:34:01Z |
| publishDate | 2022-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Asian Earth Sciences: X |
| spelling | doaj.art-1e66b33f0b774661bf2620f26b6c6c972022-12-22T00:25:42ZengElsevierJournal of Asian Earth Sciences: X2590-05602022-06-017100093Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, IndiaPankajini Mahanta0Sabyasachi Maiti1Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur- 721302, Dist.- West Midnapore, West Bengal, IndiaCorresponding author.; Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur- 721302, Dist.- West Midnapore, West Bengal, IndiaGeochemical alteration indexes viz. carbonate chlorite pyrite index, ishikawa alteration index, hashiguchi alteration index, chemical alteration index and silicification index are conventionally used to study the degree and type of alteration. Thin section microscopic and X-ray Fluorescence analysis got similar roles for alteration study. Due to sparse and expensive sampling, the regional depiction of alteration patterns and their quantitative analysis are usually unavailable for exploration geologists. Here, we provided an alternative remote proxy-based approach to map the degree and type of alteration on a large scale, using visible-near infrared and shortwave infrared bundles of WorldView-3 imagery. The chosen study area is sparsely vegetated Lawa gold deposit in the North Singhbhum Mobile Belt, India. Partial least squares regression (PLSR) modelling of geochemical alteration indexes with reflectance spectra was used to understand the spatial variation in the degree of alterations. The remotely derived alteration indexes can be linked with field and microscopic studies of Cu-Au mineralization. We found dominance of alteration processes in the following order: ferruginisation, silicification, sericitization and chloritization. Demarcated intensely hydrothermally altered zones are present near the exposed mineralized outcrop. In addition, we identified new alteration zones with ore phases as a plausible mineralized zone.http://www.sciencedirect.com/science/article/pii/S2590056022000147WorldView-3Alteration mappingGeochemical alteration indexPartial least squares regressionVegetated region |
| spellingShingle | Pankajini Mahanta Sabyasachi Maiti Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India Journal of Asian Earth Sciences: X WorldView-3 Alteration mapping Geochemical alteration index Partial least squares regression Vegetated region |
| title | Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India |
| title_full | Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India |
| title_fullStr | Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India |
| title_full_unstemmed | Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India |
| title_short | Remote geochemical alteration proxy for mineral exploration: A case study from Lawa gold mines, India |
| title_sort | remote geochemical alteration proxy for mineral exploration a case study from lawa gold mines india |
| topic | WorldView-3 Alteration mapping Geochemical alteration index Partial least squares regression Vegetated region |
| url | http://www.sciencedirect.com/science/article/pii/S2590056022000147 |
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