Hyperspectral image analysis of different carbonate lithologies (limestone, karst and hydrothermal dolomites): the Pozalagua Quarry case study (Cantabria, North‐west Spain)

TLDR

Ground‑based hyperspectral imaging combined with terrestrial lidar scanning is a novel technique for outcrop analysis applied to Early and Late Albian carbonates of the Pozalagua Quarry, and spectral absorption signatures link specific sedimentary or diagenetic products—including recent and palaeokarst, hydrothermal karst, fractures, and dolomite types—to iron, manganese, organic matter, clay, and water content. The study aims to enable quantitative evaluation of sedimentary and diagenetic features in inaccessible outcrops using this technique. An image‑processing workflow was developed to differentiate limestone from dolomite, provide additional sedimentary and diagenetic information, and quantitatively delineate diagenetic phases with high.

Abstract

Abstract Ground‐based hyperspectral imaging combined with terrestrial lidar scanning is a novel technique for outcrop analysis, which has been applied to Early and Late Albian carbonates of the Pozalagua Quarry (Cantabrian Mountains, Spain). An image processing workflow has been developed for differentiating limestone from dolomite, providing additional sedimentary and diagenetic information, and the possibility to quantitatively delineate diagenetic phases in an accurate way. Spectral absorption signatures can be linked to specific sedimentary or diagenetic products, such as recent and palaeokarst, hydrothermal karst, (solution enlarged) fractures and different dolomite types. Some of the spectral signatures are related to iron, manganese, organic matter, clay and/or water content. Ground‐truthing accessible parts of the quarry showed that the classification based on hyperspectral image interpretation was very accurate. This technique opens the possibility for quantitative data evaluation on sedimentary and diagenetic features in inaccessible outcrops. This study demonstrates the potential of ground‐based imaging spectroscopy to provide information about the chemical–mineralogical distribution in outcrops, which could otherwise not be established using conventional field methods.