Detection of mineralogical and lithological transitions in igneous Intrusion-Limestone boundaries using close-range hyperspectral remote Sensing: A resource perspective
This study presents an innovative solution for detecting complex geological formations, particularly in areas where field surveys are difficult or impossible. Even when feasible, conventional surveys often fail to delineate subtle lithological transitions without extensive laboratory analysis, which...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-08-01
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| Series: | International Journal of Applied Earth Observations and Geoinformation |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1569843225003668 |
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| Summary: | This study presents an innovative solution for detecting complex geological formations, particularly in areas where field surveys are difficult or impossible. Even when feasible, conventional surveys often fail to delineate subtle lithological transitions without extensive laboratory analysis, which alone cannot define spatial distribution. We interpreted the geology of an inaccessible limestone quarry using an integrated approach combining petrographic, chemical, and spectral analyses with close-range hyperspectral remote sensing. Petrographic and chemical analyses revealed that the outcrop was significantly altered by igneous intrusion, resulting in distinct mineralogical and lithological transitions within both igneous and carbonate bodies. Late-stage magmatic and hydrothermal activity produced four discrete igneous phases and widespread metasomatism. Hydrothermal alteration caused extensive dolomitization, transforming the original limestone units. These transitions are characterized by calcite and sericite formations in igneous rocks and quartz in carbonate rocks. Spectrally, dyke displayed Al-OH absorption indicative of plagioclase and sericite, while metasomatic interactions introduced secondary calcite with additional CO32– absorption. Dolomitization is further distinguished by Mg-OH absorption features. A 3D-CNNs model combined with spectral normalization effectively mapped these transition lithologies, clearly revealing the geological processes imprinted in the outcrop. Most dykes show intensive metasomatic, with only core portions retain pure igneous signatures. Limestones are concentrated near dyke contacts, suggesting marble formation via contact metamorphism, while dolostone dominated the outcrop due to regional dolomitization. The mapping results provide a preliminary resource assessment indicating that igneous intrusion has reduced the economic value by approximately 80% compared to pure limestone. This integrated approach accurately represents gradational lithological boundaries, addressing the limitations of conventional survey methods. |
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| ISSN: | 1569-8432 |